[Federal Register Volume 65, Number 131 (Friday, July 7, 2000)]
[Proposed Rules]
[Pages 42122-42185]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-16149]


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DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 70, 75 and 90

RIN 1219-AB14


Verification of Underground Coal Mine Operators' Dust Control 
Plans and Compliance Sampling for Respirable Dust

AGENCY: Mine Safety and Health Administration (MSHA), Labor.

ACTION: Proposed rule; notice of hearings.

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SUMMARY: MSHA is proposing to revoke existing operator respirable dust 
sampling procedures under parts 70 and 90, and to implement new 
regulations that would require each underground coal mine operator to 
have a verified mine ventilation plan. Under this proposal, MSHA would 
verify the effectiveness of the mine ventilation plan for each 
mechanized mining unit (MMU) in controlling respirable dust under 
typical mining conditions. MSHA would collect full-shift respirable 
dust samples, called ``verification samples,'' to demonstrate the 
adequacy of the dust control parameters specified in the mine 
ventilation plan in maintaining the concentration of respirable coal 
mine and quartz dust at or below 2.0 mg/m\3\ and 100 g/m\3\, 
respectively. The adequacy of these parameters would be demonstrated on 
shifts during which the amount of the material produced is at or above 
the ``verification production level'' (VPL) or the tenth highest 
production level recorded in the most recent 30 production shifts.

[[Page 42123]]

    The proposal would require mine operators to: First, set and 
maintain the dust control parameters during MSHA verification sampling 
at levels specified in the plan; second, maintain and make available to 
MSHA records of the amount of material produced by each mechanized 
mining unit during each production shift; and third, additional 
information in mine ventilation plans. For longwall mine operations, 
MSHA is also proposing to permit the use of either approved powered, 
air-purifying respirators (PAPRs) or verifiable administrative controls 
as a supplemental means of compliance if MSHA has determined that 
further reduction in respirable dust levels cannot be achieved using 
all feasible engineering or environmental controls appropriate for the 
operational conditions involved. In addition, through this rule, MSHA 
would conduct all compliance and abatement sampling under existing 
parts 70 and 90.

DATES: Comments on the proposed rule should be submitted on or before 
August 7, 2000.
    We are also announcing that we will hold public hearings on the 
proposed rule within 30 to 45 days of the publication of this rule. The 
hearing dates, times and specific locations will be announced by a 
separate document in the Federal Register. The rulemaking record will 
remain open 7 days after the last public hearing.

ADDRESSES: You may use mail, facsimile (fax), or electronic mail to 
send your comments to MSHA. Clearly identify comments as such and send 
them--(1) By mail to: Carol J. Jones, Director, Office of Standards, 
Regulations, and Variances, MSHA, 4015 Wilson Boulevard, Room 631, 
Arlington, VA 22203;
    (2) By fax to: MSHA, Office of Standards, Regulations, and 
Variances, 703-235-5551; or
    (3) By electronic mail to: [email protected]. Written comments on 
the information collection requirements may be submitted directly to 
the Office of Information and Regulatory Affairs, OMB, New Executive 
Office Building, 725 17th Street, NW, Washington, DC 20503, Attn: Desk 
Officer for MSHA; and to Carol J. Jones, Director, Office of Standards, 
Regulations, and Variances, MSHA 4015 Wilson Boulevard, Room 631, 
Arlington, VA 22203; by facsimile to MSHA, at 703-235-5551; or by 
electronic mail to [email protected].
    The hearings will be held in the following locations: Prestonsburg, 
Kentucky, (Jenny Wiley State Resort Park); Morgantown, West Virginia; 
and Salt Lake City, Utah. The hearing dates, times and specific 
locations will be announced by a separate document in the Federal 
Register.

FOR FURTHER INFORMATION CONTACT: Carol J. Jones, Director, Office of 
Standards, Regulations, and Variances, MSHA; 703-235-1910.

SUPPLEMENTARY INFORMATION:

I. Table of Contents

    The preamble discusses: revocation of existing operator respirable 
dust sampling requirements, revised procedures for adjusting the 
respirable dust standard when quartz is present, the proposed rule, 
engineering controls for respirable coal mine dust, dust control 
parameters, supplemental controls, health effects of exposure to 
respirable coal mine dust, degree and significance of the reduction in 
the number of shifts during which there are overexposures, an analysis 
of the technological and economical feasibility of this proposed rule, 
and regulatory impact and flexibility analyses.
    The preamble discussion follows this outline:

I. Table of Contents
II. Background
    A. Coal Mine Respirable Dust Task Group
    B. Advisory Committee on the Elimination of Pneumoconiosis Among 
Coal Mine Workers
III. General Discussion
    A. Revocation of the Operator Dust Sampling Program
    1. Pre-1980 Sampling Program
    2. Post-1980 Sampling Program
    3. Issues Affecting the Credibility of Operator Compliance 
Sampling
    4. Proposed Reforms to the Respirable Dust Monitoring Program
    a. Bimonthly Sampling
    b. Abatement Sampling
    c. Advantages of MSHA Compliance Sampling Over Existing Program
    B. Revised Procedures for Setting the Applicable Dust Standard 
When Quartz is Present
    1. Current Procedures
    2. Proposed Revised Procedures
    3. Validity of Averaging Percentages
    C. Respirable Dust Control Program for Underground Coal Mines
    1. Evaluating and Approving Plan Requirements for Respirable 
Dust Control
    2. Compliance with Plan Requirements for Respirable Dust Control
    3. Monitoring Effectiveness of Plan Requirements for Respirable 
Dust Control
    (a) Monitoring by Mine Operators
    (b) Monitoring by MSHA
    4. Proposed Procedures for Evaluating, Approving, and Monitoring 
Plan Requirements
    D. Hierarchy of Dust Controls
    1. Selection of Respirators: Loose-Fitting PAPRs
    2. Protection Factor for Loose-fitting Powered, Air-Purifying 
Respirators
    E. Guidelines for Determining What is a Feasible Dust Control
    F. Application of Continuous Monitoring Technology to Prevent 
Overexposure on Individual Shifts
IV. Discussion of Proposed Rule
    A. Summary
    B. Section-by-Section Discussion
V. Health Effects
    A. Introduction
    B. Hazard Identification
    1. Agent: Coal
    2. Physical State: Coal Mine Dust
    3. Biological Action: Respirable Coal Mine Dust
    C. Health Effects of Respirable Coal Mine Dust
    1. Description of Major Health Effects
    a. Simple Coal Workers' Pneumoconiosis (CWP) and Progressive 
Massive Fibrosis (PMF)
    b. Other Health Effects
    2. Toxicological Literature
    3. Epidemiological Literature
    a. Simple Coal Workers' Pneumoconiosis (CWP) and Progressive 
Massive Fibrosis (PMF)
    b. Other Health Effects
VI. Quantitative Risk Assessment
VII. Significance of Risk
VIII. Feasibility Issues
    A. Technological Feasibility
    B. Economic Feasibility
IX. Regulatory Impact Analysis
    A. Costs and Benefits: Executive Order 12866
    1. Compliance Costs
    2. Benefits
    B. Regulatory Flexibility Certification and Initial Regulatory 
Flexibility Analysis
X. Other Statutory Requirements
    A. Plain Language
    B. Unfunded Mandates Reform Act of 1995
    C. Paperwork Reduction Act of 1995
    D. National Environmental Protection Act
    E. Executive Order 12630 (Governmental Actions and Interference 
with Constitutionally Protected Property Rights)
    F. Executive Order 12988 (Civil Justice)
    G. Executive Order 13045 (Protection of Children from 
Environmental Health Risks and Safety Risks)
    H. Executive Order 13084 (Consultation and Coordination with 
Indian Tribal Governments)
    I. Executive Order 13132 (Federalism)
XI. Public Hearings
    Appendix A. Derivation of the Critical Values
    Appendix B. References
XII. Regulatory Text

II. Background

    Maintaining a work environment free of excessive levels of 
respirable coal mine dust and quartz dust (respirable dust) is 
essential for long-term health protection. Through the joint 
promulgation of the single, full-shift sample and plan verification 
proposals, miners would be further protected from the debilitating 
effects of occupational

[[Page 42124]]

respiratory disease by limiting their exposures to respirable coal mine 
dust to no more than the applicable standard on each shift.\1\
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    \1\ For details, see Quantitative Risk Assessment and 
Significance of Risk Sections.
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    Section 202(b)(2) of the Federal Mine Safety and Health Act of 1977 
(Mine Act) requires each operator to continuously maintain the average 
concentration of respirable dust in the mine atmosphere, during each 
shift to which each miner in the active workings of such mine is 
exposed, at or below 2.0 milligrams of respirable dust per cubic meter 
of air (mg/m\3\). Under current MSHA regulations, when coal mine dust 
contains more than five percent quartz, the respirable coal mine dust 
standard is further reduced, by means of a formula. Although MSHA does 
not currently enforce a separate standard for respirable quartz dust, 
the formula (10 divided by the percentage quartz) used to establish an 
applicable dust standard, in effect, limits quartz concentrations to 
100 g/m\3\.
    Consistent with the Mine Act and MSHA regulations, the primary 
focus of the federal respirable dust program is on controlling the 
concentrations of respirable dust in the work environment where miners 
work or travel through the application of feasible environmental or 
engineering control measures. Engineering or environmental control of 
respirable dust in the mine environment is the ultimate dust-control 
technique and the principal method for protecting miners' health. These 
include all methods that control respirable dust levels in the air that 
a miner breathes by either reducing dust generation, or by suppressing, 
diluting, capturing or diverting the dust that is being generated by 
the mining process. Under the Mine Act, the mine operator has primary 
responsibility for implementing a program to control respirable dust so 
that all miners work in an environment free of excessive levels of 
respirable dust. For full compliance, mine operators must develop, 
implement, and maintain effective engineering or environmental control 
measures, and evaluate them at regular intervals to assure that they 
function as intended. These control measures or ``dust control 
parameters,'' are specified in the dust control portion of the 
operator's mine ventilation plan currently required under Sec. 75.370.
    Mine ventilation plans are a long-recognized means of addressing 
health issues that are mine specific and for achieving work 
environments that are free of excessive concentrations of respirable 
dust. Currently, section 75.370 requires each operator of an 
underground coal mine to develop and follow a ventilation plan that is 
designed to control methane and respirable dust in the mine. The plan 
must be suitable to the conditions and mining systems employed at the 
mine. Although ventilation plans must be designed to control respirable 
dust, there is no requirement that the plan's effectiveness be 
verified.
    The dust control portion of the mine ventilation plan is a key 
element of the operator's strategy to control respirable dust in the 
working environment of each mechanized mining unit (MMU) during each 
shift. Section 70.2 defines an MMU to mean ``a unit of mining equipment 
including hand loading equipment used for the production of material.'' 
The plans provide a description of specific engineering control 
measures in use. The plans also contain procedures for maintenance of 
specific dust control equipment, such as scrubbers, dust collectors on 
roof bolters, and spray nozzles, or for the replacement of cutting 
picks to minimize dust generation. Once approved by the District 
Manager, the dust control parameters must be employed on a continuous 
basis. By monitoring the parameters, one can be assured that respirable 
dust levels are being adequately controlled without needing to rely on 
repeated dust sample analyses.
    Implementing dust control parameters, which have been determined 
effective under typical mining conditions, and maintaining these 
controls in proper working order provides reasonable assurance that no 
miner will be overexposed. Because technology that continuously 
monitors respirable dust and displays dust concentrations in real-time 
is not currently used in underground coal mines, adhering to effective 
ventilation plans is the only practical means of reasonably assuring, 
on a continuous basis, that miners are not overexposed. In 1996, MSHA 
implemented revised ventilation standards which, among other 
provisions, required an on-shift examination of the dust control 
parameters before coal production begins on each MMU. Based on the 
recommendations of the MSHA Task Group (MSHA, 1992), this requirement 
is intended to focus attention on the need for properly functioning 
dust controls before production begins. On-shift examinations of dust 
control parameters under existing Sec. 75.362 are important for an 
effective respirable dust control strategy.
    Recent advances in technology may make it feasible to continuously 
monitor certain parameters such as, air quantity and velocity, and 
spray water flow rate and pressure (Spencer, et al. 1996). Section 
75.362 encourages the use of such monitors as it would eliminate the 
need for periodic physical measurements of some dust controls to verify 
if they are operating properly. Although current technology allows for 
real-time data on the performance, the condition of key dust control 
parameters, and for immediate modification of controls, MSHA is not 
aware of its use by any operator.
    Since establishment of the first comprehensive dust standards in 
1969, the implementation of ventilation plans by mine operators and 
their enforcement by MSHA has had a significant impact on control of 
dust levels in underground coal mines. For example, based on federal 
mine inspector sampling results, the average dust concentration in the 
environment of a continuous miner operator (occupation code--036) has 
been reduced by 86 percent over the past 30 years, from 7.7 mg/m\3\ to 
approximately 1.1 mg/m\3\. This accounts for the significant decline in 
the percentage of operator continuous miner designated occupation (DO) 
samples exceeding 2.0 mg/m\3\, from 49 percent (over 32,000 samples/
shifts) in 1971, to 10 percent (over 2,500 samples/shifts) in 1999. 
Analysis of all valid operator DO samples indicates that in 1971, the 
2.0 mg/m\3\-dust standard was exceeded on 53,463 (44 percent) of the 
122,404 shifts sampled, compared to 3,002 (10 percent) of the 28,727 
shifts sampled in 1999 (MSHA, DO Samples by Calendar Year, 1999). 
Despite this progress, MSHA has found evidence that a significant 
number of overexposures still occur on the shifts sampled during which 
the approved dust control parameters are operating at or above approved 
levels. This evidence suggests that it is highly probable that some 
miners are overexposed to respirable dust on shifts not sampled by 
either the operator or by MSHA. In addition, recent medical 
surveillance data suggests that miners continue to be at risk of 
developing simple coal workers' pneumoconiosis (CWP), progressive 
massive fibrosis (PMF) and silicosis (Elam, April 1999).
    Certain aspects of the current respirable dust program limit MSHA's 
ability to assure the adequacy of the dust control parameters under 
typical mining conditions according to two expert panels which reviewed 
the federal program designed to prevent pneumoconiosis among coal 
miners. Both the Coal Mine Respirable Dust Task Group, an interagency 
task group

[[Page 42125]]

established in 1991 by the Assistant Secretary for Mine Safety and 
Health, and the Advisory Committee on the Elimination of Pneumoconiosis 
Among Coal Mine Workers, established in 1995 by the Secretary of Labor, 
considered all aspects of the respirable coal mine dust control program 
and made recommendations for improvement.

A. Coal Mine Respirable Dust Task Group

    In response to concerns about the Federal coal mine dust program 
(MSHA, 1992), MSHA's Coal Mine Respirable Dust Task Group (the Task 
Group) undertook an extensive review of the program to control 
respirable coal mine dust and made recommendations to improve the 
program in 1991. As part of that review, MSHA developed a special 
respirable dust ``spot inspection program'' (SIP). This program was 
designed to provide the Agency and the Task Group with information on 
the dust levels to which underground miners are typically exposed. 
Among other recommendations, the Task Group recommended that MSHA 
require mine ventilation plans to be effective under typical mining 
conditions.
    The Task Group found that MSHA's current program did not promote 
the development and implementation of quality plans. Based on its 
review of a representative number of dust control plans, the Task Group 
found that some plans lacked specificity or did not include all the 
dust control parameters actually used. For example, the plans for three 
major underground coal mines listed the air quantity, the primary means 
of controlling concentrations of respirable coal mine dust, to be 
18,000 cubic feet per minute (cfm) in the mining section. The actual 
quantities measured by MSHA inspectors at these mines during the SIP 
varied from 40,000 cfm to over 120,000 cfm.
    Based on a review of MSHA Form 2000-86 (Revised), Respirable Dust 
Sampling and Monitoring Data, similar differences were found between 
air quantity specified in approved ventilation plans and the levels 
observed at a number of longwall MMUs inspected in 1999. For example, 
20 of the 47 longwall MMUs were using significantly more air than 
specified in the ventilation plan (MSHA, September 1999). Under these 
circumstances, it would be impossible to assess whether the air volume 
specified in the plan was adequate to maintain dust concentrations at 
or below the applicable dust standard. It should be noted that air 
volume quantities, air velocities, water spray pressures, etc., 
specified in the plan are considered to be a minimum and MSHA 
encourages mine operators to exceed their plan parameters, but only 
after the levels specified in the plan have been shown to be effective 
under the conditions in effect during sampling. In addition, a lack of 
specificity in some plans made it difficult for MSHA inspectors to 
determine whether the operator was complying with the approved plan. 
Although several plans indicated that the mining equipment was to be 
provided with water sprays, the plan did not specify the location of 
the sprays or the water pressure at the spray nozzle.
    The Task Group determined that the use of minimum production levels 
for evaluating the effectiveness of dust control parameters can result 
in marginal or inadequate plans. A more detailed discussion of the 
impact of production on the quality of dust control parameters 
specified in mine ventilation plans is provided later in this document 
(in sections III.C.1. and IV.B.). Currently, MSHA relies on information 
provided by the operator to determine at what production level the plan 
should be evaluated. No production records are required for each MMU. 
Although operators must submit production data on a quarterly basis, 
the data is compiled for the entire mine. In addition, these quarterly 
reports provide information on the amount of clean coal produced, which 
are much lower than the tonnage of total material produced, and are not 
useful for establishing what constitutes a ``normal production shifts'' 
for sampling purposes.
    A follow-up survey conducted by MSHA in 1994 found that 43 percent 
or 539 of the 1,245 producing MMUs, worked at least a 9-hour shift. The 
Task Group also concluded that current regulations limiting the 
duration of sampling to eight hours do not provide for adequate 
assessment of respirable dust exposure during nontraditional shifts of 
more than eight hours.
    Implementation of the Task Group recommendations would have 
required regulatory change. The effort to implement these changes was 
suspended pending the recommendations of Advisory Committee on the 
Elimination of Pneumoconiosis Among Coal Mine Workers, which was 
convened in 1995.

B. Advisory Committee on the Elimination of Pneumoconiosis Among Coal 
Mine Workers

    On January 31, 1995, the Secretary of Labor established the 
Advisory Committee on the Elimination of Pneumoconiosis Among Coal Mine 
Workers (the Advisory Committee). The Advisory Committee was chartered 
to ``make recommendations for improving the program to control 
respirable coal mine dust in underground and surface mines in the 
United States.'' The Advisory Committee identified and addressed many 
of the same issues considered by the Task Group. Findings and consensus 
recommendations were developed for each issue (MSHA, 1996). The 
Advisory Committee concluded that the dust control portion of the mine 
ventilation plan is the key element of an operator's strategy to 
control respirable dust in the work environment. They concluded that 
the initial evaluation, approval, in-mine verification and monitoring 
to demonstrate the effectiveness of the operator's proposed dust 
control plan is critical for the protection of miners from lung 
disease. Also, believing that the credibility of the current system of 
mine operator sampling to monitor compliance with exposure limits has 
been severely compromised, the Advisory Committee concluded that 
restoration of miner and mine operator confidence in the respirable 
coal mine dust sampling program should be one of MSHA's highest 
priorities. Accordingly, there was unanimous agreement that in order to 
restore confidence in the program MSHA should take full responsibility 
for all compliance sampling currently being carried out by mine 
operators under 30 CFR parts 70 and 90.
    The November 1996 Advisory Committee Report recommended numerous 
improvements for the federal program to protect miners from simple CWP, 
PMF, and silicosis. Of these, the following have been incorporated in 
this proposal:
    1. MSHA should take full responsibility for all compliance sampling 
at a level which assures representative samples of respirable dust 
exposures under usual conditions of work without adversely impacting 
the remainder of the Agency's resources and responsibilities.
    2. MSHA should, in consultation with the operator, perform 
scheduled independent dust monitoring to verify the operator's plan.
    3. MSHA should redefine the range of production levels which must 
be maintained during sampling to verify the plan. The value should be 
sufficiently close to maximum anticipated production level in order to 
reasonably assure that the plan would be effective under typical 
operations.
    4. MSHA should review compliance and production records to 
determine when there is a need for plan verification and modification.

[[Page 42126]]

    5. MSHA should require that the results and monitoring of dust 
control parameters and production be recorded in order to correlate 
dust control parameters with dust measurements.
    This proposal is intended to eliminate overexposures on individual 
shifts and to restore the confidence of miners and mine operators in 
the respirable coal mine dust sampling program by addressing the 
shortcomings identified by the Task Group and the Advisory Committee in 
the current respirable coal mine dust program. The proposal would 
revoke the operator dust sampling programs under 30 CFR parts 70 and 90 
and require the implementation of mine ventilation plans demonstrated 
to be effective in maintaining respirable dust at or below the 
applicable standard on each shift. These ventilation plans would be 
verified by MSHA using single, full-shift respirable dust samples. The 
plans' effectiveness would be monitored on a regular basis by the use 
of inspector single, full-shift samples. The proposed rule regarding 
the use of single, full-shift measurements of respirable coal mine dust 
to determine average concentration is also published in today's Federal 
Register.
    MSHA recognizes that the Secretary of Labor's Advisory Committee on 
the Elimination of Pneumoconiosis Among Coal Workers made several 
recommendations that also impact on surface coal mine workers. These 
surface coal mine issues will be addressed by the agency in a separate 
rulemaking which is currently underway. The scope of that rulemaking 
will include many of the issues that are addressed in this underground 
rule including requirements for duct control plans, verification of 
dust control plans prior to approval, on shift examination of dust 
control measures, and the elimination of operator sampling for 
compliance purposes.

III. General Discussion

    This section describes the current respirable coal mine dust 
program and the role of mine ventilation plans in safeguarding the 
health of miners. Specifically, this section details:
    (1) The reasoning behind MSHA's decision to revoke the operator 
dust sampling programs under 30 CFR parts 70 and 90 and to take full 
responsibility for all compliance sampling;
    (2) The proposed procedures for arriving at an average quartz 
percentage that is used to establish an applicable dust standard under 
Secs. 70.101 and 90.101;
    (3) The existing means for evaluating the effectiveness of dust 
control parameters stipulated in mine ventilation plans;
    (4) The plan approval process;
    (5) Methods of assuring compliance with plan requirements; and
    (6) MSHA's efforts to monitor plan effectiveness on a regular 
basis.

There is also a detailed discussion of the hierarchy of dust controls 
and the continued need for mine ventilation plans to specify dust 
control parameters in order to preserve the primacy of engineering 
controls. Finally, as a possible alternative to plan verification, we 
have included a discussion and a request for comments on the 
application of personal continuous monitoring technology which is, or 
may become available, to prevent overexposure on individual shifts.

A. Revocation of the Operator Dust Sampling Program

    Under the Federal Coal Mine Health and Safety Act of 1969 (Coal 
Act) coal mine operators were required to take accurate dust samples at 
periodic intervals to measure the amount of respirable dust in the mine 
atmosphere where miners work or travel. The Coal Act also required that 
citations be issued whenever respirable dust samples collected either 
by an operator or by federal mine inspectors showed noncompliance with 
the applicable dust standard. The Coal Act was amended in 1977 (Mine 
Act), but the respirable dust provisions remained essentially 
unchanged.
1. Pre-1980 Sampling Program
    In 1970, federal regulations were issued that established the first 
comprehensive coal mine operator dust sampling program. Those 
regulations required the environment of the occupation on a working 
section, or MMU, exposed to the highest respirable dust concentration 
to be sampled--the ``high risk'' occupation concept. All other miners 
working in the MMU in less risky occupations were assumed to be 
protected from excessive concentrations of respirable coal mine dust if 
the high risk occupation was in compliance. Under the program, each 
operator was required to initially collect and submit ten valid 
respirable dust samples to determine the average dust concentration 
(across ten production shifts). If analysis showed the average dust 
concentration to be within the applicable dust standard, the operator 
was required to submit only five valid samples a month. If compliance 
continued to be demonstrated, the operator was required to submit only 
five valid samples every other month. The initial, monthly, and 
bimonthly sampling cycles were referred to as the ``original,'' 
``standard,'' and ``alternative'' sampling cycles, respectively. When 
the average dust concentrations exceeded the standard, the operator 
reverted back to the standard sampling cycle.
    Additionally, each working miner was sampled individually every 120 
or 180 days, depending on the miner's work assignment, or every 90 days 
for each miner (now referred to as a part 90 miner) who had a positive 
chest x-ray for coal workers' pneumoconiosis (CWP) and who elected to 
exercise the option of transferring to a less dusty area. However, 
except for the part 90 miner results, these early individual sample 
results were not used for enforcement, but were forwarded to the 
National Institute for Occupational Safety and Health (NIOSH) to 
develop a comprehensive exposure data base for research concerning 
black lung disease. Each sample was accompanied by a completed mine 
data card that included, among other things, the occupation and social 
security number of the sampled miner. This information was also 
included in the Agency's computer print-out of sampling results that 
was sent to mine operators.
2. Post-1980 Sampling Program
    In 1980, following hearings held throughout the coal fields (in 
1977 and 1978), regulations governing operator sampling were 
substantially revised by reducing the operator sampling burden, to 
simplify the sampling process, and to enhance the overall quality of 
the sampling program. The result was to replace the various sampling 
cycles with a bimonthly sampling cycle and to eliminate the requirement 
that each working miner be sampled. These are the regulations that 
currently govern the mine operator dust sampling program. Like the 1970 
rules, the current regulations continue to rely on sampling the 
environment of the DO in the MMU that is exposed to the greatest 
concentration of respirable coal mine dust, but reduced the number of 
shifts required to be sampled from ten to five.
    Other changes included replacing the requirement that each working 
miner be sampled individually with the bimonthly collection of one 
sample from each ``designated area'' (DA) to measure the dust 
concentrations associated with dust-generating sources in the active 
workings of the mine, such as along haulage ways, at underground 
crushers, or at transfer points. These locations are strategically 
selected so that the environment where miners normally work or travel 
is monitored for compliance with the applicable dust

[[Page 42127]]

standard. The operator's approved ventilation plan identifies the 
specific locations where DA samples are required to be collected and 
the dust control measures used at these locations. Another change was 
to increase the frequency of sampling part 90 miners from every 90 days 
to one sample every 60 days.
    The revised regulations also eliminated the reporting of personal 
identifiers on the dust data card due to miner concerns that the data 
may be used by mine operators to characterize the exposure of an 
individual miner in future black lung claims. It also provided for 
sampling equipment to be properly maintained and calibrated, and 
examined during the shift. Additionally, operators' were required to 
demonstrate a certain level of competence by passing a test 
administered by MSHA. Since proper use of sampling equipment is 
essential to the integrity of the sampling process, the certification 
requirement was intended to provide reasonable assurance that the 
person conducting sampling was competent to perform the task. After 
samples have been collected, certified persons are required to properly 
fill out the dust data card that accompanies each filter cassette. 
These samples must then be transmitted unaltered to MSHA within 24 
hours after the end of each sampling shift, to expedite compliance 
determinations and minimize periods of miner overexposure.
    While not specified in the regulations, operators are permitted by 
practice to note on the dust data card any reason why they believe the 
sample(s) transmitted are not valid and should not be used by MSHA to 
determine compliance. Generally, such samples are voided by MSHA and 
the operator is required to submit a substitute sample within that 
bimonthly sampling period.
    MSHA may also determine that an operator sample is invalid for many 
of the same reasons. MSHA may also void operator samples for technical 
and administrative reasons, such as samples submitted in excess of the 
number required, or DO samples if they were not taken during a ``normal 
production shift.'' ``Normal production shift'' is defined in existing 
Secs. 70.2(k)(1), 70.207(a) and (d) as a ``production shift during 
which the amount of material produced * * * is at least 50 percent of 
the average production for the last set of five valid samples * * *''
    After MSHA has processed the samples, the operator is provided with 
a report of the sample results, which must be posted on the mine 
bulletin board for a period of 31 days to provide miners ready access 
to current information on respirable dust conditions in the mine. 
Operators are also required to report to MSHA in writing any change in 
the operating status of the mine, mining unit, or designated area that 
affects the sampling requirements, within three working days after the 
change occurs.
    An operator who is found to be in violation of the reduced dust 
standard is issued a citation and must take steps to reduce the dust 
levels. After corrections have been made, the operator must collect 
five additional samples within a time period specified by MSHA to 
demonstrate compliance.
    During the development of the 1980 regulations for operator 
sampling requirements, we received comments that indicated a lack of 
confidence in our reliance on operator samples for enforcement 
purposes. In response to these concerns, MSHA published a proposed 
regulation in 1980 that would have provided miners' representatives the 
right to observe each phase of the operator dust sampling process with 
no loss in pay. The proposal intended to promote better cooperation 
between mine operators and miners in order to improve the effectiveness 
of the program. In 1985, the Agency decided not to finalize regulations 
to provide miners' representatives the right to observe operator 
sampling, stating that compliance with the 1980 revisions to the 
sampling program had resulted in greater confidence in the overall dust 
program.
3. Issues Affecting the Credibility of Operator Compliance Sampling
    As noted earlier in this proposal, there is general agreement that 
significant efforts have been made during the past 30 years to reduce 
dust levels in our Nation's mines. While most mine operators have 
conscientiously attempted to sample miners' exposure to respirable coal 
mine dust as required by regulation, because of the actions of some, 
the operator sampling program continues to be plagued by allegations of 
fraudulent sampling practices. Despite MSHA's efforts to improve the 
quality of the operator dust sampling program and to vigorously 
investigate such allegations and prosecute violators, sampling 
irregularities continue to be documented involving the physical 
alteration of the weight of dust collected on the filter, or the 
collection of samples in low-dust areas of the mine or even outside of 
the mine.
    The Advisory Committee found that during the 10 years prior to the 
publication of their report, serious questions had been raised 
regarding the representativeness of respirable dust levels measured by 
mine operators, the handling of filter cassettes, and the changing of 
work assignments and/or working conditions during sample collection. 
The credibility of the operator sampling program was questioned by 
almost all the representatives of miners who testified before the 
Advisory Committee. Since 1990, more than 160 mine operators, agents 
and contractors have pled or been found guilty of submitting fraudulent 
samples to MSHA. These disclosures correspond with the concerns 
expressed by critics of the operator sampling program.
    Detailed reviews of the respirable dust program by the Task Group 
and the Advisory Committee identified aspects of the current program 
that have the potential to negatively affect validity of sampling 
results which could impact miner health protection and, consequently, 
its credibility in the minds of the very people the program was 
designed to protect, the miner. For example, to effectively monitor the 
mine environment where miners work or travel, it is essential that 
respirable dust samples are ``representative,'' in that they reflect 
typical dust conditions to which miners are exposed. The recurrent 
pattern of disclosures of tampering with the sampling process has 
highlighted the vulnerability of the current monitoring system to the 
submission of unrepresentative samples. For example, during the period 
1980 to 1990, over 137,000 of the 750,000, or approximately 18 percent 
of the operator DO samples showed extremely low concentrations (less 
than or equal to 0.1 mg/m\3\), compared to 10 percent for the MSHA 
samples. Since 1990, 14 percent of the operator DO samples and 3 
percent of the MSHA samples were equal to 0.1 mg/m\3\.
    The fact that sampling is controlled by the mine operator also 
allows the operator to determine when and under what conditions samples 
will be collected during all current bimonthly and abatement sampling. 
This permits the operator to conduct sampling during those periods in 
the mining cycle when conditions are anticipated to result in lower 
dust levels in the mine environment. For example, the operator may 
choose to sample during periods when the volume of air on the MMU is 
greatest or when ventilation controls are operating at optimum 
efficiently. Accordingly, these sample results may not be 
representative of typical exposure levels. Other aspects of the 
monitoring system that may allow the submission of unrepresentative 
samples were reported by the Task Group in its report of

[[Page 42128]]

findings. Because some operators do not sample every bimonthly period 
or fail to submit the required number of bimonthly samples, miners may 
be potentially exposed to excessive levels of respirable dust.
4. Proposed Reforms to the Respirable Dust Monitoring Program
    Believing that one of MSHA's highest priorities must be to restore 
the confidence of miners and mine operators in the respirable coal mine 
dust sampling program, one of the Advisory Committee's key 
recommendations was that MSHA take full responsibility for all 
compliance sampling at a level which assures representative samples of 
respirable dust exposure under usual conditions of work. It also 
recommended that compliance sampling should be carried out at a number 
and frequency at least at the level required of operators and MSHA.
    Accordingly, MSHA is proposing to revoke the operator dust sampling 
programs under 30 CFR parts 70 and 90 and to take full responsibility 
for all compliance sampling (i.e., bimonthly and abatement sampling), 
in a manner that it believes will be more protective than the current 
operator sampling program. MSHA intends to monitor miners' dust 
exposure and compliance with the dust control provisions of the 
approved mine ventilation plan, or with the respirable dust control 
plan for a part 90 miner at underground mines, in accordance with the 
procedures and guidelines established in Chapter 1 of the Coal Mine 
Health Inspection Procedures Handbook, as modified herein.
(a) Bimonthly Sampling
    MSHA would collect a full-shift sample from the working environment 
of at least five different occupations, if available, on each producing 
MMU, instead of sampling only the DO for five consecutive shifts or on 
shifts worked on five consecutive days as under the current bimonthly 
sampling program. Proposed revised Sec. 70.2(j) defines full shift, for 
purposes of bimonthly compliance sampling, as the entire work shift 
including travel time but excluding any time in excess of 480 minutes. 
A full-shift sample would also be collected from each DA located inby 
the section dumping point (i.e., intake air and roof bolter DAs) 
bimonthly, and from all other DAs once each year. All part 90 miners 
would be sampled bimonthly as under the current program.
    MSHA would issue a citation for noncompliance when a single, full-
shift measurement demonstrates, at a high level of confidence, that the 
applicable dust standard is exceeded. Although MSHA would collect 
multiple occupational samples from each MMU, we would issue only one 
citation on a single shift on any one MMU unless more than one dust-
generating source was involved.
(b) Abatement Sampling
    Under this proposal, MSHA would also assume responsibility for all 
abatement sampling. As recommended by the Advisory Committee, MSHA 
would utilize single, full-shift samples to demonstrate abatement. 
Since the criteria under which the effectiveness of ventilation plans 
are required to be verified are significantly more stringent than those 
for bimonthly sampling, MSHA does not anticipate issuing many citations 
to MMUs and sectional DAs. However, should an MMU be cited for 
violation of the applicable dust standard, and a determination be made 
by the inspector who was onsite that the dust control parameters are no 
longer adequate for the present operating conditions, MSHA would 
require the operator to revise the dust control portion of the mine 
ventilation plan under proposed Sec. 70.219. MSHA would then verify the 
effectiveness of the revised plan. Citations for violating the 
applicable dust standard would not be based on verification sampling.
    If on the other hand, a determination is made that a change in the 
plan is not warranted, the operator would take corrective action to 
prevent miners from being exposed on subsequent shifts. MSHA would then 
sample the MMU, similarly to bimonthly compliance purposes described 
previously in paragraph (a) of this section. All five of the 
occupational samples taken on a single shift would have to be below the 
applicable standard to demonstrate abatement. If any sample result 
exceeds the applicable standard, but not at a sufficiently high level 
of confidence to warrant a citation, then MSHA may sample additional 
shifts or initiate the plan verification process.
    We solicit comments on whether MSHA should require a higher level 
of confidence that the applicable standards are being complied with 
before abating a citation for excessive dust. Specifically, should 
abatement determinations be based on the critical values specified in 
Sec. 70.209? We also solicit comments on whether abatement sampling 
should be conducted at or above the Verification Production Level (VPL) 
as defined in Sec. 70.2(aa). Requiring that abatement be demonstrated 
under more typical production conditions, as represented by the VPL, 
would provide assurance that miners will continue to be protected on a 
majority of the production shifts.
    MSHA proposes to conduct abatement sampling involving non-MMU DAs 
and part 90 miners in the same way as it conducts bimonthly sampling. A 
violation would be abated if the result of an abatement sample was less 
than the applicable standard. If sample results exceed the applicable 
standard but not at a sufficiently high level of confidence to warrant 
a citation, MSHA may collect additional single, full-shift samples.
    As in the case of MMU abatement samples, we solicit comments on 
whether MSHA should require a higher level of confidence that abatement 
samples for non-MMU DAs and for part 90 miners demonstrate compliance 
with the applicable standards before abating a citation for excessive 
dust. Specifically, should abatement determinations be based on the 
critical values specified in Sec. 70.209?
(c) Advantages of MSHA Compliance Sampling Over Existing Program
    According to section 101(a)(9) of the Mine Act, no health standard 
promulgated under this title shall reduce the protection afforded 
miners by an existing mandatory health standard.
    For the reasons listed below, MSHA believes that, through the joint 
promulgation of this proposed rule and the proposed single, full-shift 
sample rule, miners would be further protected from the debilitating 
effects of occupational respiratory disease by limiting their exposures 
to respirable coal mine dust and quartz dust on every shift.
     Providing and maintaining a work environment free of 
excessive levels of respirable dust is essential for long-term health 
protection. While monitoring of the work environment provides an 
indication of how effective the existing dust control measures are, 
monitoring alone does not control dust levels. Requiring mine operators 
to implement and maintain dust control parameters which, for the first 
time, have been determined effective under typical mining conditions, 
will provide reasonable assurance that no miner will be overexposed on 
individual shifts.
     Implementing single, full-shift sample determinations will 
more likely detect excessive dust concentrations and thus protect 
miners. Averaging samples taken on multiple shifts can mask 
overexposures on individual shifts. Although MSHA would be sampling 
fewer shifts, MSHA believes the proposed sampling methodology

[[Page 42129]]

would provide a more accurate representation of dust conditions to 
which miners are exposed.
     Under the existing operator sampling program, only the DO 
is sampled. Under the proposed program, MSHA would sample multiple 
occupations on the same shift. This would provide a more comprehensive 
assessment of dust conditions to which miners are exposed.
     Since MSHA will be doing all the sampling, we will be able 
to monitor the dust control parameters and work practices in effect 
during sampling. This will enable MSHA to determine the effectiveness 
of the operator dust control program.
     Unlike the current sampling program, which allows 
operators control over when to sample and under what operating 
conditions, MSHA's visits will be unannounced. As a result, all phases 
of the mining cycle are likely to be sampled eventually (i.e., 
construction activity, longwall start-up, turning crosscuts, etc.), and 
samples should be more representative of typical mining conditions.
     The miners' representative will have walkaround rights 
during sampling, thereby increasing miners' confidence in the dust 
sampling program.

B. Procedures for Setting the Applicable Dust Standard When Quartz is 
Present

    Section 202(b)(2) of the Mine Act and the implementing MSHA 
regulations require each operator to continuously maintain the average 
concentration of respirable dust in the mine atmosphere during each 
shift to which each miner in the active workings of such mine is 
exposed at or below 2.0 mg/m\3\. Under current MSHA regulations in 
Secs. 70.101, and 90.101, the applicable coal mine dust standard is 
lowered further, by means of a formula (10 divided by the percentage of 
quartz) prescribed by Secretary of Health, Education, and Welfare in 
1971, whenever the respirable coal mine dust in the mine atmosphere of 
the active workings contains more than five percent quartz. \2\ This is 
based on the recognition that the toxicity of coal mine dust increases 
when higher levels of quartz are present. Consequently, as the quartz 
content of respirable coal mine dust present in the mine atmosphere 
increases over five percent, the applicable respirable coal mine dust 
standard is correspondingly lowered. For example, if 10 percent quartz 
was present, the mine operator would have to continuously maintain 
respirable dust at or below 1.0 mg/m\3\.
---------------------------------------------------------------------------

    \2\ The applicable dust standard for intake air in 
Sec. 70.100(b) and for miners who have exercised rights under part 
90 regulations in Sec. 90.100 is 1.0 mg/m\3\. Those standards are 
also lowered if quartz exceeds 5 percent. However, no effect occurs 
until the quartz content exceeds 10 percent.
---------------------------------------------------------------------------

    The following provides an overview of MSHA's current and proposed 
revised procedures for arriving at an average quartz percentage that is 
used to establish an applicable dust standard.
1. Current Procedures
    Until 1985, the applicable dust standard was adjusted based on the 
percentage of quartz determined from a single, full-shift (8 hours or 
less in duration) respirable dust sample taken by an MSHA inspector. 
Since MSHA sampled less frequently than we currently do, a reduced 
standard could remain in place anywhere from 12 to 24 months. During 
that period the level of quartz could have either increased or 
decreased significantly. As a result in December 1985, MSHA implemented 
the procedures in effect. This program, for the first time, enabled 
mine operators to participate voluntarily in the process of setting 
reduced dust standards. These procedures are contained in Chapter 1 of 
MSHA's Coal Mine Health Inspection Procedures Handbook.
    The most significant program change involved the use of individual 
quartz percentages determined from one MSHA and, under certain 
conditions, up to two coal mine operator full-shift respirable dust 
samples, referred to as ``optional samples,'' to arrive at an average 
quartz percentage. It also provides for the automatic reevaluation of 
work areas and occupations on a reduced dust standard every six months.
    Under the existing system, if an MSHA sample contains more than 
five percent quartz, an operator is afforded the opportunity to submit 
an optional sample. Provided it has sufficient weight gain (0.45 mg), 
the quartz content will be averaged with the MSHA sample when sample 
results do not differ by more than  2.0 percent, and the 
standard set accordingly. If an operator fails to submit an optional 
sample or it contains insufficient weight for analysis, the standard is 
adjusted based on the MSHA sample alone. Operators are afforded the 
ability to submit a second optional sample whenever sample results 
differ by more than  2.0 percent. All three results are 
then used to compute the average quartz percentage.
    Also, in November 1994, MSHA refined its analytical procedure 
enabling us to analyze inspector low-mass respirable dust samples 
(0.100 to 0.449 mg) for quartz. Only those samples containing 25 
micrograms or more of quartz were used in the standard-setting process. 
However, this change applied only to filters that were preweighed to 
0.001 mg for use by MSHA enforcement personnel. It did not apply to 
operator-submitted optional samples, which were collected with filters 
preweighed to 0.01 mg, for which we required a minimum of 0.45 mg of 
dust to be analyzed for quartz. The ability to accurately analyze 
samples containing small amounts of dust reinforced MSHA's views about 
the severity of quartz exposures in some coal mining operations.
    A review of MSHA data for FY 1999 shows that of the 778 entities 
(i.e., MMUs, DAs, designated work positions (DWPs), roof bolters, and 
part 90 miners) (MSHA, Results of Quartz Sampling Operator Involvement, 
1999) placed on an initial reduced standard as a result of an MSHA 
sample containing more than five percent quartz, 753 (96 percent) of 
the entities submitted an optional sample. One would expect the level 
of participation to be high since failure to respond would result in 
the setting of a lowered dust standard based on the result of the MSHA 
sample, which first triggered the standard-setting process. Of the 753 
entities submitting an optional sample, 231 were afforded the ability 
to submit a second optional sample (Ibid.). Again, as expected, over 73 
percent (170) of those 231 entities submitted a second optional sample, 
probably because doing so could reduce the quartz average quartz 
percentage used to establish the applicable dust standard. For 
comparison, in FY 1992, 93 percent of the operators afforded the 
opportunity submitted an optional first sample, and 82 percent of the 
operators given the opportunity submitted a second optional sample.
    However, as the following data show, operator participation tended 
to decline significantly when operators were given the opportunity to 
submit samples involving established entities on reduced standards. Of 
the 1122 entities given the option to submit a sample, only 450 or 29 
percent responded, compared to 96 percent for entities placed on an 
initial reduced standard. In 1992, 32 percent of the operators elected 
to participate.
2. Proposed Revised Procedures
    Consistent with MSHA's decision to assume full responsibility for 
compliance sampling, the Agency is also proposing to rely only on MSHA 
samples as the basis for setting the applicable dust standard when 
quartz is present. As discussed below, while the proposed scheme 
reduces the burden and cost on mine operators to take and

[[Page 42130]]

submit optional samples, it does not diminish the protections afforded 
operators under the current program. It continues to consider temporal 
variability associated with quartz determinations by averaging three 
MSHA samples collected on different shifts. MSHA recently published a 
proposed ``Program Policy Letter (PPL) on Samples Used to Determine the 
Respirable Dust Level When Quartz is Present'' for public comment [64 
FR 65671, November 23, 1999] whereby the applicable dust standard would 
be set based on the results of multiple MSHA samples. It proposes that 
mine operator samples would no longer be used in combination with MSHA 
samples to determine the average quartz percentage that is used to set 
an applicable dust standard. In the proposed rule, MSHA is adopting the 
sampling approach set out in the PPL. The proposed rule supercedes the 
proposed PPL, and consequently, the proposed PPL is withdrawn.
    We believe that results under the proposed process will be more 
representative of the quartz level to which miners are exposed. Unlike 
the current process, which may cause a standard to be set based on the 
quartz content of a single MSHA sample, three valid MSHA samples would 
be used to set a reduced standard under the proposed revised procedures 
[64 FR 65671].\3\ Since MSHA is sampling underground mines bimonthly 
and surface mines semi-annually, we will have no difficulty in 
collecting the required number of samples to arrive at the average 
quartz percentage. If initial sampling shows that miners may be exposed 
to excessive levels of quartz, MSHA intends to sample at a greater 
frequency to ensure that miners are being protected. This level of 
sampling should also allay any operator concerns regarding the 
collection of ``misleadingly high'' samples during atypical periods. 
MSHA would also begin reporting quartz levels to the nearest tenth of a 
percent. This is intended to be more protective for the miner than the 
current truncation of results to a full percentage point.
---------------------------------------------------------------------------

    \3\ Unlike MSHA's objective in compliance sampling, the 
objective in measuring quartz content is to establish a reduced 
standard that will apply to all shifts. This enables an operator to 
design a ventilation plan that will be protective on every shift. 
Therefore, it is appropriate to estimate the quartz content by 
averaging quartz measurements obtained over an extended time period.
---------------------------------------------------------------------------

    Under the proposed revised procedures, when an MSHA sample contains 
more than five percent quartz, we would average the percent of quartz 
present in three most recent MSHA respirable coal mine dust samples to 
set the applicable dust standard. If an MMU, DA, DWP, or part 90 miner 
is already on a reduced standard, a new applicable dust standard will 
be established by averaging the results of the first two MSHA samples 
taken under the proposed procedures with the quartz percentage 
associated with the reduced standard in effect. If fewer than two MSHA 
samples are taken, the existing reduced standard will continue to 
remain in effect.
    Assume an MMU is on a 1.0 mg/m\3\-standard (10 percent quartz). If 
the first MSHA sample contains 7.2 percent of quartz, the existing 
standard of 1.0 mg/m\3\ would continue to remain in effect. If, 
however, the next sample contains 16.1 percent, the average quartz 
percentage would be 11.1 percent [(10.0% + 7.2% + 16.1%)  3 = 
11.1%], resulting in a 0.9 mg/m\3\-standard (10  
11.1% = 0.9 mg/m\3\). For MMUs, DAs, DWPs, or part 90 miners not on a 
reduced standard, MSHA would collect and analyze three samples for 
quartz to determine if a reduced standard was warranted.
    Under the proposed procedures, if the newly-established standard is 
lower than the one in effect, the new standard would become effective 
seven days after the date of the notice informing the mine operator of 
the change in the applicable dust standard. However, if it is higher 
than the current standard, the newly-established dust standard would 
become effective on the date of the notice.
    As published elsewhere in today's Federal Register, MSHA is also 
proposing to take enforcement actions on the basis of inspector single, 
full-shift, respirable dust measurements. For entities on a reduced 
standard, MSHA would delay any enforcement action until the sample is 
analyzed for quartz. If an exposure measurement significantly exceeds 
the existing standard and the quartz content of that sample would cause 
the standard to be lowered below the existing reduced standard, the 
operator would be cited for violation of the applicable standard 
currently in effect. On the other hand, if the quartz content of the 
sample would cause the dust standard and the corresponding citation 
threshold value (CTV) to increase so that the single, full-shift 
measurement would no longer indicate noncompliance, no citation would 
be issued. This is illustrated by way of the following example.
    For example, suppose that the MMU is on a 1.3-mg/m\3\ standard and 
a single, full-shift measurement of 1.6 mg/m\3\ is obtained. Since this 
measurement exceeds the applicable standard, the operator is in 
violation of the standard. However, analysis of the DO sample shows 
that the sample contained 6 percent quartz which, if used, would result 
in a 1.7-mg/m\3\ standard. This indicates that the quartz level in the 
environment of the DO has changed, suggesting that the current standard 
may no longer be valid. Therefore, since the original measurement of 
1.6 mg/m\3\ is less than the 1.7-mg/m\3\ standard that should have been 
in effect on the shift sampled, a citation should not be issued.
    Since MSHA samples are viewed to be more representative of the 
respirable dust concentration to which miners are exposed, MSHA is 
proposing to revise section 70.101 to clarify that the Secretary will 
determine the quartz level by sampling. Operator samples may no longer 
be submitted for determining the applicable standard. It is our belief 
that the procedures being proposed for setting reduced standards should 
be more protective for the miners than those in effect. The proposed 
approach provides for stringent monitoring exposure to quartz which is 
consistent with Advisory Committee's recommendation that MSHA increase 
surveillance and reduce exposure to this serious health hazard.
    As under the current program, if operating conditions should change 
following establishment of a lowered dust standard that affect the 
level of quartz in the working environment, mine operators or miners' 
representatives will be able to request MSHA to conduct a quartz 
reevaluation. In the absence of continuous monitoring, mine operators 
should be cautious in preventing overexposures when abnormal conditions 
(such as cutting rock to install an overcast or other frequent but 
short-lived events involving cutting of rock) are encountered between 
MSHA sampling visits.
3. Validity of Averaging Percentages
    The average quartz percentage used to set the applicable dust 
standard for a particular sampling location or area of a mine is 
determined in accordance with accepted mathematical procedures for 
arriving at an average value from a set of values (i.e., adding 
together the individual quartz percentages and dividing by the number 
of analyses that are in the set). MSHA believes that this is the most 
appropriate method to use.
    One commenter who responded to the PPL (op cit.) contended that 
MSHA's approach of arriving at the average quartz percentage was 
mathematically incorrect. This commenter recommended that, to more 
accurately

[[Page 42131]]

reflect the true quartz concentration, the average quartz percentage be 
calculated by dividing total mass of quartz in micrograms by the total 
mass of dust collected (based on three samples in the example 
submitted). In the commenter's example, the average percentage obtained 
using MSHA's proposed averaging method was larger than that obtained 
using the commenter's approach.
    The following two scenarios in Table III-1 clearly demonstrate that 
MSHA's averaging method does not always result in a larger average 
quartz percentage value.

         Table III-1.--For Two Scenarios, Using Alternate Methods, Percent of Quartz in Respirable Dust
----------------------------------------------------------------------------------------------------------------
                       Scenario I                                               Scenario II
----------------------------------------------------------------------------------------------------------------
    Dust mass           SiO2 mass            % SiO2           Dust mass          SiO2 mass           % SiO2
----------------------------------------------------------------------------------------------------------------
           1.7               0.136                  8                1.7               0.17                 10
           1.0               0.04                   4                1.0               0.08                  8
           2.5               0.3                   12                2.5               0.15                  6
----------------------------------------------------------------------------------------------------------------
 MSHA's Method             Average of % SiO2 = 8           MSHA's Method            Average of % SiO2 = 8
----------------------------------------------------------------------------------------------------------------
   Commenter's                                               Commenter's
         Method      Sum (SiO2 Mass)  Sum (Dust           Method      Sum (SiO2 Mass)  Sum (Dust
                                Mass) = 9.2%                                             Mass) = 7.7%
----------------------------------------------------------------------------------------------------------------

    These examples show that for situations where MSHA would have 
determined a quartz percentage of 8 percent, the commenter's method 
would yield 9 percent in one case and 7 percent in the other.

C. Respirable Dust Control Program for Underground Coal Mines

    The primary focus of the underground coal mine respirable dust 
program is to limit the concentration of respirable dust to which 
miners are exposed in the work environment. To ensure that miners are 
not being exposed to excessive concentrations of respirable dust, 
current regulations require mine operators to:
     Design a mine ventilation plan that effectively controls 
respirable dust under typical mining conditions;
     Implement the plan's dust control parameters when approved 
by MSHA before commencing production;
     Maintain the dust control parameters specified in the 
approved plan and to monitor their function and operation through 
required on-shift examinations; and
     Evaluate their effectiveness with bimonthly samples in 
order to provide reasonable assurance that the dust control parameters 
continue to function as intended.
    To control dust in the work environment, existing Sec. 75.370 
requires mine operators to develop and submit ventilation plans that 
are designed to control methane and respirable dust in the mine to MSHA 
for approval. Each plan must be suitable to the conditions and mining 
system in use at the mine. These plans provide detailed requirements 
for the protection of miners by specifying engineering controls. These 
engineering controls may include:
     The quantity and the velocity of the air current used to 
ventilate the MMU;
     The number, type, and location of water sprays;
     The pressure and quantity of water delivered by the 
sprays; and
     Additional environmental controls, such as dust scrubbers 
or devices which collect mine air and filter out dust particles.
    Plans also contain procedures for maintenance of dust control 
equipment used on the mining machine and roof bolter. Mine operators 
frequently do not fully describe all dust controls in use at the mine. 
If such information is not fully disclosed, it is impossible for MSHA 
to fully enforce the plan provisions and to determine when the MMU is 
out of compliance with the ventilation plan.
    When an operator submits a proposed mine ventilation plan or 
revision in accordance with Sec. 75.370, the MSHA district office 
reviews it for completeness and adequacy. The District Manager will 
approve the plan if it meets MSHA requirements, and he is confident 
that the dust control parameters specified will have a reasonable 
likelihood of maintaining dust concentrations within the allowable 
limits. Most proposed plans or revisions are approved immediately, or 
tentatively approved, based on engineering judgement, or experience, or 
both, until they are assessed by MSHA inspector sampling or, to a 
lesser extent and only under certain circumstances, by mine operator 
bimonthly sampling. Generally, MSHA samples within 60 days of plan 
approval. Current regulations prohibit a mine operator from initiating 
any mining activity without an approved ventilation plan. MSHA allows 
operators to commence mining by granting tentative approval. However, 
plans may be implemented which are later determined to be inadequate 
under typical mining conditions under the existing process.
1. Evaluating and Approving Plan Requirements for Respirable Dust 
Control
    Under the current program, the effectiveness of the plan's dust 
control parameters is assessed through sampling of the DO and other 
occupations associated with the MMU. Since there is no requirement for 
verifying plan effectiveness, we have had to rely on samples that may 
not be representative of dust concentrations to which miners are 
exposed.
    MSHA sampled annually at each underground mine until recently. The 
Agency now samples bimonthly in each underground coal mine. This 
increased sampling effort is part of MSHA's initiative to increase 
confidence in the federal respirable dust program and to eliminate 
simple CWP, PMF, and silicosis among coal miners. During sampling 
inspections, we monitor compliance with the applicable dust standard, 
measure the concentration of respirable quartz dust; and identify 
occupations other than the DO that the mine operator should routinely 
monitor because they are at risk of exposure to excessive 
concentrations of respirable dust.
    Under current inspection procedures, MSHA inspectors sample at 
least five different occupations, if available, on each MMU on each 
shift. Samples are normally taken under the mining conditions in effect 
during sampling. In conjunction with this sampling, the MSHA inspector 
checks and measures the dust control parameters early in the shift to 
determine whether the ventilation plan is being followed. The inspector 
records the findings, and all

[[Page 42132]]

the dust controls and work practices in use during sampling on MSHA 
Form 2000-86 (Revised), Respirable Dust Sampling and Monitoring Data. 
MSHA will issue a citation if the mine operator fails to follow any of 
the dust control parameters specified in the plan. Normally, the 
citation requires immediate corrective action to abate the violation. 
This may involve, for example, unplugging some water sprays or 
increasing the amount of ventilating air delivered to the MMU. At the 
conclusion of the sampling shift for an MMU, the inspector determines 
the total amount of material that was mined (in tons) during the shift.
    If the average concentration of the samples taken in one shift is 
less than, or equal to, the applicable standard, and the actual 
production is at least 60 percent of the average production over the 
last 30 production shifts, the MSHA inspector will normally terminate 
sampling after the first day and will recommend that the plan 
parameters be approved by the District Manager. This would occur even 
if the samples were found to contain more than 5 percent of quartz. 
Such a finding could result in MSHA lowering the dust standard below 
that in effect at the MMU. Since 1985, MSHA has provided mine operators 
the opportunity to participate in the process to establish a lower dust 
standard based on the level of quartz. Mine operators can submit up to 
two optional samples which are averaged with the MSHA sample to 
determine the average percentage of quartz which is used to establish a 
new dust standard for the MMU. MSHA published a proposed Program Policy 
Letter for comment (64 FR 65671, November 23, 1999) whereby the 
standard would be determined based solely on the results of multiple 
MSHA samples. Under that proposal, mine operator samples would no 
longer be used to calculate a reduced dust standard. Instead, 
applicable dust standards will be set based solely on the results of 
MSHA samples.
    If the average concentration falls below the standard in effect, 
but one or more samples exceed it, no decision is made regarding the 
plan's effectiveness or regarding compliance with the applicable 
standard. Instead, the inspector must collect additional samples on 
subsequent production days or shifts to establish that the dust control 
provisions of the ventilation plan are adequate.
    To a lesser extent, if MSHA is unable to schedule a mine visit 
within the period established by the individual district, the District 
Manager may rely on the results of operator bimonthly sampling to 
approve a plan. Generally, this occurs in the case where a plan is 
upgraded with a change which has been established as effective. MSHA 
does not routinely approve plans based on operator bimonthly sampling 
because these samples may be collected during periods when production 
is not reflective of typical production levels. The current program 
permits the operator to submit samples which may not be representative 
of normal dust conditions in the working environment. Under current 
regulations, operator bimonthly samples will be considered valid, 
unless voided by MSHA, when the MMU produces at least 50 percent of the 
average level reported for the last set of five valid bimonthly 
samples. Since a mine's ``normal production'' level for sampling 
purposes and the typical production level may diverge greatly over the 
course of several sampling periods, granting approval under these 
conditions may not reflect the plan's effectiveness under more typical 
mining conditions.
2. Compliance with Plan Requirements for Respirable Dust Control
    Once MSHA determines that the dust control measures are adequate 
and approves the mine ventilation plan, the specified dust control 
parameters are to be employed on a continuous basis to safeguard the 
health of miners. Since maintaining the approved dust control 
parameters provides reasonable assurance that respirable dust can be 
controlled, failure to comply with these requirements would defeat the 
purpose of the mine ventilation plan and needlessly expose miners to 
excessive concentrations of respirable dust. Section 75.362 requires 
mine operators to perform an on-shift examination of the dust control 
parameters before the MMU begins production in order to assure full 
compliance. Any deficiencies must be corrected before production 
begins.
    Compliance with approved plan parameters is checked during MSHA's 
routine sampling inspections: as part of six-month plan reviews, during 
other non-sampling inspections or investigations, or in conjunction 
with an ongoing sampling inspection.
3. Monitoring Effectiveness of Plan Requirements for Respirable Dust 
Control
    Because of the dynamic nature of mining, conditions can change 
significantly in a short period of time. For example, an increase in 
the concentration of respirable quartz dust will require the applicable 
standard to be reduced below the level that was effective when the dust 
control parameters were first evaluated. Such changes can directly 
impact the effectiveness of the dust-control measures. It is important 
to regularly monitor the adequacy of the approved dust control 
requirements to ensure that they remain suitable for the current 
conditions at the mine and to determine whether the plan should be 
upgraded. Currently, both MSHA and the mine operator regularly monitor 
the operator's dust control program. However, for MMUs the mine 
operator is responsible for making sure that all provisions of the 
ventilation plan are in effect on every shift.
    (a) Monitoring by Mine Operators. Since 1980, the current 
regulations have required mine operators to take five valid samples 
from the DO in each MMU on a bimonthly basis and submit them to MSHA 
for processing, to determine compliance with the applicable dust 
standard. Section 70.207(e) identifies the DO for each method of 
mining. These are collected either on consecutive normal production 
shifts, or on production shifts worked on consecutive days, during 
which the amount of material produced by the MMU is at least 50 percent 
of the average production reported for the last bimonthly sampling 
period. These samples must be collected portal-to-portal during the 
entire shift or for 8 hours, whichever time is less.
    Bimonthly samples have provided a periodic evaluation of the 
quality of the air miners breathe. They also have provided some insight 
into the effectiveness of the operator's dust control system on the 
days in which the samples are taken. Mine operators may exceed their 
minimum plan requirements once they have been approved as effective 
under current evaluation criteria. Currently, there is no requirement 
for mine operators to record the dust control measures in use as part 
of the on-shift examination. Because there is no requirement for such 
records, MSHA cannot assess the continued adequacy of the approved dust 
control requirements unless the inspector observes the sampling 
process.
    Although the current operator sampling program may limit the 
utility of bimonthly samples for plan approval purposes, they allow 
MSHA to identify approved plans that may no longer be suitable to the 
conditions at a mine. If multiple individual samples, or their average, 
exceed the applicable dust standard after the required on-shift 
examination has been conducted, the approved plan parameters may no 
longer be effective and may need to be upgraded. If cited, the operator 
must

[[Page 42133]]

take corrective action to lower the concentration of respirable dust to 
within the permissible concentration as described in current 
Sec. 70.201(d). The operator must demonstrate, through sampling, that 
the underlying condition(s) which caused the violation has been 
corrected. Since MSHA inspectors are not present to observe the 
action(s) taken by the operator to abate the violation, the ventilation 
plan is usually not amended to include the changes the operators make 
to the parameters in order to abate the violation. However, if the 
operator has a record of noncompliance and MSHA determines that the 
approved plan parameters may no longer be adequate, MSHA will notify 
the operator to submit an improved plan. Under current plan approval 
procedures, if the operator fails to address MSHA's concerns after 
receiving the second notification, MSHA will move to revoke the 
operator's mine ventilation plan. If the plan is revoked, the mine must 
not operate.
    As discussed earlier, MSHA is proposing to revoke operators' 
sampling program in underground mines and assume full responsibility 
for all compliance sampling.
    (b) Monitoring by MSHA. One of the objectives of MSHA's dust 
sampling program is to verify that the controls specified in the 
approved mine ventilation plan continue to control concentrations of 
respirable dust under existing mining conditions. As part of this 
program, the dust control parameters must be checked and measured early 
in the shift to assure compliance with the approved plan. These checks 
also verify that the operator is performing the required on-shift 
examinations. Operators have the opportunity to adjust their dust 
controls to reflect that which has been approved so the plan can be 
evaluated. However, most operators choose not to make adjustments for a 
number of reasons. While inspection procedures require the ventilation 
plan to include the dust control measures in use during the evaluation, 
most approved plans do not incorporate all the measures that were 
actually in place during MSHA sampling. This makes it difficult for 
MSHA to assess the continued adequacy of the approved dust control 
parameters. Frequently, decisions must be based only on prior 
experience or engineering judgment.
    When an operator is cited based on MSHA samples, the inspector may 
require the operator to describe what type of corrective action will be 
taken. However, if a plan change is required, MSHA must follow similar 
plan approval procedures. The operator must be notified in writing that 
the plan is inadequate. In this case, MSHA has sample results and a 
record of the actual parameters in place which can be used to document 
the need for a plan change. Most plans which are revised simply 
incorporate only those dust controls that were in use when MSHA 
sampled.
    MSHA reviews each mine ventilation plan every six months under 
Sec. 75.370. The review includes: all plan revisions, respirable dust 
inspection reports, citations for exceeding the applicable dust 
standard, and comments from representatives of miners. When a 
deficiency in the respirable dust control portion of the plan is found, 
the MSHA inspector records comments on MSHA Form 2000-86. MSHA sends 
these results to the mine operator along with an explanation of whether 
the operator must make any changes, the reasons for the changes, and 
the date for submitting a plan revision. MSHA will send a second 
notification if the operator fails to respond. MSHA may revoke the 
operator's mine ventilation plan if the operator does not comply.
4. Proposed Procedures for Evaluating, Approving, and Monitoring 
Ventilation Plan Requirements
    The dust control portion of the mine ventilation plan is the key 
element of an operator's strategy to control respirable dust in the 
work environment, thereby protecting miners. In recognition of this, 
MSHA's proposal makes a number of changes to the process for 
evaluating, approving, and monitoring mine ventilation plans, many of 
which are based on the Advisory Committee's recommendations.
    Consistent with the Advisory Committee recommendations, MSHA 
proposes to add provisions to verify the effectiveness of the 
ventilation plan in controlling dust, at a production level high enough 
to demonstrate the plan's effectiveness under typical operating 
conditions. This would require that MSHA implement procedures for 
reviewing compliance and production records. It would also require that 
dust control parameters and production associated with samples on a 
given shift be recorded in order to demonstrate that parameters 
specified continue to be effective in controlling dust.
    This proposal would require a ventilation plan to include all 
engineering or environmental controls necessary for maintaining dust 
concentrations at acceptable levels. A plan must also include any 
specific work practices or other means used to supplement these 
controls in order to minimize the dust exposure of individual miners. 
Unlike plans under the current program, you would have to identify all 
measures necessary for achieving continuous compliance with the 
applicable dust standard in the plan.
    MSHA proposes to require you to include information on the length 
of each normal production shift in Sec. 75.371(f) and to specify the 
VPL as defined in Sec. 70.2 in every ventilation plan. The VPL is the 
tenth highest production level recorded in the most recent 30 
production shifts. This value will represent the minimum production 
level at which effectiveness of the plan must be demonstrated.
    We believe that the production criteria used to evaluate plan 
effectiveness may not adequately represent typical conditions under 
which miners work. Requiring that plans be verified at or above the VPL 
would provide assurance that excessive dust concentrations will be 
avoided, even on shifts with higher-than-average production. This is 
more protective of miners than the current practice of evaluating plan 
adequacy based on MSHA inspector samples taken when production can be 
as low as 60 percent of the average production.
    MSHA would require you to maintain records of the amount of 
material produced by each MMU during each shift. This would enable you 
to establish the VPL. Because verification of a plan's effectiveness is 
conditioned on the VPL, these records are necessary to ensure that the 
VPL continues to represent higher-than-average production. Although a 
VPL would be included in the ventilation plan, MSHA would not cite you 
for producing at levels exceeding the VPL.
    Under the proposed plan verification procedures, MSHA will notify 
you of when we intend to initiate verification sampling. To enable MSHA 
to evaluate the effectiveness of the plan parameters at or above the 
VPL, you must make sure that all the dust control parameters specified 
in your ventilation plan are fully implemented. On the date scheduled 
for verification sampling, you should arrange to be producing at or 
above the VPL specified in the plan, using only the dust control 
parameters and other measures listed in the plan.
    Under the proposal, MSHA would perform the sampling necessary to 
verify your plan. We will collect full-shift samples from the work 
environment of multiple occupations on each MMU, including the DO. We 
will collect all samples in accordance with procedures described in 
Chapter 1 of MSHA's Coal Mine Health Inspection Procedures Handbook (op 
cit.). In addition, on every shift on which we

[[Page 42134]]

collect verification samples, we would measure and record all of the 
quantitative engineering or environmental parameters. We would also 
record any other means used to reduce miners' dust exposure on the 
sampled shift. We will provide you with this information, along with 
verification sample results, for posting on your mine bulletin board.
    In accordance with section 103(f) of the Mine Act, you must provide 
miners and their representatives the same walkaround rights during plan 
verification sampling as they are provided during any other physical 
inspection made pursuant to the provisions of section 103(a) by an 
authorized representative of MSHA.\4\
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    \4\ MSHA believes that under the guidance of the Interpretive 
Bulletin 43 FR 17546 (April 25, 1978) these rights arise when: (1) 
an ``inspection'' is made for the purposes set forth in section 
103(a), and (2) the inspector is physically present at the mine to 
observe or monitor safety and health conditions as part of direct 
safety and health enforcement activity.
    Verification sampling is necessary to obtain information related 
to approval of the mine's ventilation plan and whether coal mine 
dust will be adequately controlled to protect miners health. 
Consequently, miners and their representative would have the right 
to accompany the inspector with no loss of pay for the time during 
which the representative exercises this right. However, this right 
is limited by Section 103(f) to only one such representative of 
miners.
---------------------------------------------------------------------------

    Unlike the existing program, the proposal would allow you, for the 
first time, to use either approved PAPRs or verifiable administrative 
controls to supplement your engineering or environmental controls for 
compliance purposes at longwall mining operations. This would be 
permitted only on an interim basis and only after MSHA determined that 
you had exhausted all feasible engineering or environmental controls.
    Finally, under this proposal, MSHA has established rigorous 
criteria for determining when to approve a plan. We would approve a 
plan only when a sufficient number of verification samples demonstrate, 
at a high level of confidence, that the plan is effective at production 
levels at or above the VPL.

D. Hierarchy of Dust Controls

    Consistent with the Mine Act, engineering or environmental controls 
have been the principal method used for preventing or minimizing 
miners' exposure to these primary and secondary dust sources in the 
workplace over the past 30 years. Control of dust throughout the work 
environment gives reasonable assurance that all miners in the area will 
be adequately protected. Well-designed engineering or environmental 
controls provide consistent and reliable protection to all workers 
because they are not dependent upon constant human supervision or 
intervention, except for the periodic checks, to insure that they are 
functioning as intended. MSHA requires mine operators to utilize all 
feasible engineering or environmental controls, which are specified in 
the mine ventilation plan, to maintain concentrations of respirable 
dust in the work environment of MMUs at or below the applicable dust 
standard. Engineering or environmental controls include all methods 
that control the level of respirable dust by reducing dust generation 
(e.g., machine parameters) or by suppressing (e.g., water sprays, 
wetting agents, foams, water infusion, etc.), diluting (e.g., 
ventilation), capturing (e.g., dust collectors) or diverting (e.g., 
shearer clearer, passive barriers, etc.) the dust being generated by 
the mining process. The importance of using engineering or 
environmental controls was not only recognized by the Advisory 
Committee, but also by NIOSH in its criteria document: Occupational 
Exposure to Respirable Coal Mine Dust (NIOSH, 1995), when it 
recommended that such controls must continue to be relied upon as the 
primary means of protecting coal miners. The primacy of engineering or 
environmental controls is preserved under this proposal. The proposal 
requires mine operators to utilize all feasible engineering or 
environmental controls to reduce concentrations of respirable dust to a 
level at or below the applicable standard.
    Administrative controls are another method of avoiding 
overexposure. Administrative controls refer to work practices that 
reduce miner's daily exposure to respirable dust hazards by altering 
the way in which work is performed. They consist of such actions as 
rotation of miners to areas having lower dust concentrations, 
rescheduling of tasks, and modifying work activities. The Task Group 
found that administrative controls were used increasingly, even when it 
was feasible to implement additional engineering or environmental 
controls. The use of administrative controls was found to be increasing 
at mines employing longwall mining systems. The most frequent 
administrative control in use consisted of restricting the activities 
of miners required to work downwind of the longwall operator, or the 
occupation designated as 044 by MSHA. This particular form of 
administrative control is in use at some of the 51 longwall MMUs that 
were operating on October 28, 1999. MSHA has observed the use of this 
particular administrative control, even after changing the location of 
the DO from the 044 to the 060 occupation--the miner who works nearest 
the return air side of the longwall working face. Unlike engineering or 
environmental controls, to be effective, administrative controls rely 
on the ability of miners to follow specified procedures. However, 
difficulty in ensuring that miners adhere to the administrative 
controls, labor/management agreements, and limitations on the number of 
qualified miners capable of handling specific tasks may limit the use 
and effectiveness of such controls. The Advisory Committee Report 
states that the use of administrative controls does not reduce the 
operator's responsibility to maintain ambient dust levels in active 
workings at or below the standard. However, the Advisory Committee 
noted that ``while not a substitute for engineering controls, 
administrative controls, which restrict the amount of time that miners 
spend in an area with uniform exposure level, can result in lower 
personal exposures (MSHA, 1996).''
    Under the Mine Act and current regulations, mine operators are 
required to make approved respiratory equipment available to all 
affected underground miners whenever exposure to concentrations of 
respirable dust exceeds the applicable dust standard. However, miners 
are not compelled to use them. While required for interim protection, 
mine operators cannot use respirators as a substitute for engineering 
or environmental control measures. Engineering or environmental 
controls have been found to provide more consistent and reliable 
protection to all workers. In comparison to respirator programs, the 
effectiveness of engineering or environmental controls does not rely 
heavily upon constant supervision or miners' consistent and correct use 
of the equipment. Furthermore, we can measure dust concentrations to 
which miners are exposed when engineering or environmental controls are 
in use. It is more difficult to monitor the effectiveness of a 
respirator program because the assessment methods are indirect. For 
these reasons, MSHA's longstanding policy has been that respirators 
should be used in underground coal mines only as an interim method of 
protection until feasible engineering or environmental controls are 
available.
    Approved respirators are not acceptable substitutes for feasible 
engineering or environmental controls.

[[Page 42135]]

    It is MSHA's position that technology is available to control 
respirable dust to at or below the applicable standard at MMUs 
employing continuous and conventional methods of mining. However, MSHA 
recognizes that, unlike other mining systems, longwall MMUs may have 
acute dust problems caused by the face-ventilation airstream carrying 
the shearer-generated face dust over the miners working along the face 
downwind of the shearer operator (occupation code 044). This makes it 
more difficult to control the work environment on a consistent basis.
    Improvements in dust control technology have not kept pace with 
increases in production technology associated with high-production 
longwall MMUs. Average longwall shift production reported during 
bimonthly sampling has increased more than five-fold since 1980, from 
approximately 890 tons per shift (tps) to more than 4,900 tps in 1998. 
In fact, 49 percent of the shifts sampled averaged 4,000 to 8,000 tps, 
while approximately 8 percent of the shifts exceeded 8,000 tps. A major 
milestone in mining history was achieved in 1997, when a single 
longwall mine produced more than 1 million tons of coal in a single 
month (Fiscor, 1998).
    Unfortunately, as more coal is mined, greater quantities of 
respirable dust are generated. The increase in longwall production 
levels has resulted in the generation of far more dust which must be 
controlled (Webster, et al., 1990; Haney, et al., 1993; O'Green, 1994). 
According to published literature, several thousand milligrams of 
respirable dust per ton of coal cut can be formed and liberated during 
the cutting process (National Research Council, 1980). Of course, the 
quantity of respirable dust produced by the cutting process can vary 
greatly, depending on the type of coal, its moisture content, the 
amount of rock bands in the coal, sharpness of the cutting bits, the 
particular mining machine, and many other factors. Although a 
considerable amount of respirable dust is formed by the cutting 
operation, most of these particles do not become airborne. 
Nevertheless, given the amount of dust that is produced per ton of coal 
mined, a larger quantity of respirable dust would be generated from 
cutting 8,000 tons of coal than from cutting 4,000 tons. An operator is 
not required to produce, on a sampled shift, more than 50 percent of 
the average production reported during the last bimonthly period. 
Therefore, dust concentrations on sampled shifts may be substantially 
lower than what is typical and therefore not reflect the dust exposure 
on that shift.
    While significant efforts have been made to implement available 
control technology, no significant new advancements in longwall control 
technology have been reported since 1989 (U.S. Bureau of Mines, 
undated). From 1989 to 1999, the percentage of operators' longwall DO 
samples exceeding 2.0 mg/m\3\ dropped from 34 percent to 20 percent, 
reflecting the impact of the implementation of those advances in 
longwall control technology. Although this represents a significant 
improvement, especially in view of the five-fold increase in average 
shift production, the 1999 data clearly show that miners continue to be 
overexposed on a significant number of shifts.
    Over the past ten years, MSHA and the former U.S. Bureau of Mines, 
now part of NIOSH, have made unsuccessful efforts to conduct a joint 
research program that would evaluate the effectiveness of available 
longwall dust control technology. The objective of such research would 
have been to quantify the effects of employing all state-of-the-art 
dust-control technology available for a longwall operation. 
Unfortunately, such a study has never been undertaken because no 
industry partner has agreed to participate. Based on our experience, 
MSHA's position remains that feasible engineering and environmental 
controls exist for maintaining dust exposures at or below the 
applicable standard, even at longwall operations. MSHA has concluded 
that the proposed plan verification process will lead to further 
improvements in the design and quality of mine ventilation plans. At 
some high-producing longwall MMUs, however, the engineering or 
environmental controls available may not succeed in sustaining 
continuous compliance with the applicable dust standard at certain 
locations downwind of the longwall operator (occupation code--044).
    Mining industry representatives have repeatedly urged MSHA to 
accept the use of powered, air-purifying respirators (PAPRs) (e.g., 
Racal Airstream helmets),\5\ as an alternative means of 
complying with the applicable dust standard when engineering or 
environmental controls failed or were not feasible. The Airstream 
helmet originated in the early 1970s at the Safety in Mines Research 
Establishment in England which developed it primarily for mining use to 
provide protection for head, eyes, and lungs in a single convenient 
unit. Because these devices provide a continuous stream of filtered air 
over the miner's face, it has been suggested that they be viewed as 
miniature environmental controls, rather than respirators. In September 
1997, Energy West Mining Company (Energy West) petitioned the Secretary 
of Labor to amend the mandatory health standards for underground coal 
mines at 30 CFR part 70 to allow Airstream helmets or other types of 
PAPRs to be used as a supplemental means of complying with the 
applicable dust standard. The petition for rulemaking proposed that the 
Secretary issue a standard which would supersede the current interim 
statutory standard, specified in Section 202(h) of the Mine Act. Energy 
West contended that PAPRs are necessary as a supplemental means of 
controlling respirable dust because even the most diligent application 
of feasible engineering/environmental controls could not always prevent 
overexposure. MSHA has consistently acknowledged that PAPRs can be 
effective as an interim method of protecting miners when properly 
selected, used, and maintained. However, MSHA has never considered the 
Racal Airstream helmet (or the 3M\TM\ Airstream\TM\ Helmet-
Mounted PAPR), or any other respiratory protective device approved and 
labeled as such by the National Institute for Occupational Safety and 
Health (NIOSH), to be an engineering, environmental, or administrative 
control. Hence, it cannot be used as an environmental control to comply 
with the respirable dust standard.
---------------------------------------------------------------------------

    \5\ References to specific equipment, trade names or 
manufacturers does not imply endorsement by MSHA.
---------------------------------------------------------------------------

    In order to provide the greatest possible protection for all miners 
under typical mining conditions, MSHA is proposing to permit, under 
certain circumstances, the limited use of either approved loose-fitting 
PAPRs or verifiable administrative controls for compliance purposes. 
This would provide you with the flexibility to select the most 
appropriate option for supplementing your engineering or environmental 
controls. We believe that permitting longwall mine operators to use 
loose-fitting PAPRs or verifiable administrative controls for 
compliance purposes will not reduce the level of protection afforded 
longwall miners by the existing standard.
    This aspect of the proposal is limited to longwall mine operations 
because technology is available to control respirable dust at or below 
the applicable standard at MMUs employing continuous and conventional 
methods of mining. Their use at longwall operations would be permitted

[[Page 42136]]

only after MSHA determines that for a specific MMU, excessive dust 
concentrations cannot be prevented in the environment of miners 
required to work downwind of the longwall shearer operator (occupation 
code--044) by implementing all feasible engineering or environmental 
controls. We solicit comments concerning the availability of feasible 
engineering or environmental controls to lower dust levels.
1. Selection of Respirators: Loose-Fitting PAPRs
    Loose-fitting PAPRs completely surround the head and cover the face 
with a full visor or shield. The functional and physical 
characteristics of loose-fitting PAPRs as described below make them 
especially well-suited to underground coal mining conditions, and it is 
for these reasons that MSHA determined that loose-fitting PAPRs are the 
most suitable type of respirator protection for these conditions.
    A loose-fitting PAPR protects the wearer from excessive levels of 
respirable dust by providing a continuous flow of filtered air and 
imposing minimal breathing resistance upon the wearer. Loose-fitting 
PAPRs do not require fit-testing,\6 7\ unlike tight-fitting 
respirators. Furthermore, it is not necessary to be clean shaven for 
this type of PAPR to be protective.
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    \6 7\ Quantitative fit testing and qualitative fit testing are 
methods used to determine the facepiece seal and fit of a tight-
fitting respirator.
---------------------------------------------------------------------------

    Loose-fitting PAPRs provide safety advantages over other forms of 
PAPRs or tight-fitting respirators. In addition to protecting the 
lungs, the helmet and visor of a PAPR can simultaneously protect the 
eyes and head from high-velocity nuisance dust, spray, and small pieces 
of coal from the cutting drums and face and from loose coal falling 
from the roof. Loose-fitting PAPRs provide easier communication between 
miners, rather than the muffled communication between workers which is 
experienced between miners wearing tight-fitting facepieces.
    The Racal Airstream helmet has been in use in underground 
coal mines since the late 1970s. Over 50 percent of the longwall mines 
operating have miners who wear Airstream helmets for added protection. 
This respirator was developed primarily for mining use by the Safety in 
Mines Research Establishment (SMRE) in England. It combines face, head, 
and respiratory protection in a single convenient unit. The support 
hardware which provides the filtered air is packaged in the helmet. 
Power for the system is provided by a belt-mounted battery. Dusty air 
enters the helmet through a rear entrance port, passes through a pre-
filter assembly that removes the coarse material, and then passes 
through the fan and into a final-filter assembly that is located 
between the head of the wearer and the outer helmet shield. The 
filtered air then sweeps down across the wearer's face, behind the 
face-shield visor, and exits at the chin. Soft plastic seals join the 
face-shield visor to the sides of the head and jaw limiting entry of 
unfiltered mine air (Greenough, 1979). The original Airstream helmet 
has undergone numerous design improvements since it was first 
introduced in British coal mines in the mid 1970s. The Airstream helmet 
is produced by 3M (3M\TM\ Helmet-Mounted Airstream\TM\ series).
2. Protection Factor for Loose-fitting Powered, Air-Purifying 
Respirators
    The type and degree of protection of any respirator depends on the 
ability of a respirator to prevent hazards from entering the worker's 
breathing zone. In an underground coal mine, the level of protection 
afforded by a loose-fitting PAPR to protect a miner depends on the type 
and condition of the filter material of the air-purifying element, the 
nature and concentration of the respirable coal mine dust, proper 
maintenance of the PAPR and battery pack, and especially, how 
consistently the miner properly wears the PAPR, including having the 
visor properly lowered. The protection factor, the ratio of the 
respirable dust concentration outside the respirator to the 
concentration inside, measure how much protection a respirator might 
provide to the wearer.
    In the NIOSH Respirator Decision Logic (May 1987), based on 
simulated laboratory tests and some workplace protection tests (none of 
which replicated conditions in underground coal mines) NIOSH assigned 
loose-fitting, helmeted PAPRs, properly worn, a protection factor (APF) 
of 25. NIOSH made the following cautionary statement:

    Despite the fact that some of the PF's [APFs] have a statistical 
basis, they are still only estimates of the approximate level of 
protection. It must not be assumed that the numerical values of the 
APF's presented in this decision logic represent the absolute 
minimum level of protection that would be achieved for all workers 
in all jobs against all respiratory hazards. The industrial 
hygienist or other professional responsible for providing 
respiratory protection or evaluating respiratory protection programs 
is therefore encouraged to evaluate as accurately as possible the 
actual protection being provided by the respirator (NIOSH, May 
1987).

    Furthermore, in its Guide to Industrial Respiratory Protection 
(September 1987), published after the NIOSH Respirator Decision Logic, 
NIOSH offered an additional caveat with regard to the effectiveness of 
PAPRs:

    Until recently, powered air-purifying respirators were 
considered positive pressure devices. Field studies by NIOSH as well 
as others, have indicated that these devices are not positive 
pressure, and that their assigned protection factors are 
inappropriately high (NIOSH, September 1987).

    There is virtually no positive pressure in the PAPR. Respirable 
dust may invade the miners' breathing zone through openings along the 
side and bottom of the visor, even when it is maintained in the full 
lowered position. The extent to which respirable dust invades a miner's 
breathing zone, depends, in part, on the MMU's ventilation air velocity 
and on the miner's work rate and his angle of orientation to the 
airflow.
    Questions have arisen concerning the applicability of NIOSH's APF 
of 25 for loose-fitting PAPRs to some work environments. It has been 
contended that NIOSH overestimates the minimum level of protection 
provided in the workplace even when used within the context of a good 
respirator program (Myers, et al., 1984). The environmental conditions 
assumed in NIOSH's estimation of the APF for loose-fitting PAPRs are 
not consistent with those in underground longwall mining operations. 
For example, various unique conditions of coal mining (obstructed views 
and difficulty communicating) may compel miners to lift their visors. 
Once the visor is raised, the respirator is no longer being worn in 
accordance with conditions required for an APF of 25. Also, the high 
velocities of air customarily found on longwall mining faces, are not 
comparable to the air velocities experienced in most industry sectors 
nor in those represented in the studies used to determine the APF of 
25. The actual fit or seal of the respirator helmet to the wearer, 
repeated work-task motions in confined work spaces, raising the visor, 
and high air velocities along the longwall face all may significantly 
reduce the actual degree of protection provided in the workplace. 
Unlike an APF, an effective protection factor (EPF) reflects the 
protection provided by a respirator over an actual work shift given 
specific occupational environmental conditions such as ventilation 
velocity, when the wearer performs typical work activities and uses the 
respirator in a typical manner.
    Laboratory and in-mine studies (EPF studies) show that mine 
ventilation air flow or velocity, the primary means

[[Page 42137]]

longwall operators use to control respirable dust levels, may be the 
single biggest factor affecting the level of protection provided by the 
PAPR on a longwall mining face. Cecala, et al., (1981) found protection 
of loose fitting PAPRs (Racal Airstream helmets) to be 
inversely related to ambient air velocity in both laboratory and in-
mine settings (Ibid). In other words, increased air velocity leads to 
decreased effectiveness of the PAPR.
    The level of protection from a loose-fitting PAPR is also affected 
by the orientation of the helmet to the airflow. Cecala's wind tunnel 
tests clearly showed that, at the higher flow rates, helmet efficiency 
was greatest when facing directly against the airflow and was reduced 
when the helmet was oriented in other directions. This is extremely 
important since miners are more likely to orient their heads at an 
angle to the airflow, or to face downwind, than to face directly into 
the airflow.
    Cecala's in-mine testing of the loose-fitting, helmeted PAPRs 
produced an EPF confirming the inverse relationship between wind speed 
and the level of protection provided by PAPRs shown during wind tunnel 
testing. Air velocity in underground mines is measured in units of feet 
per minute (fpm). Under normal face-velocity conditions (less than 400 
fpm), the Airstream helmet averaged a respirable dust reduction of 84 
percent, which is equivalent to an EPF of 6.4. However, under high 
face-velocity conditions (1,200 fpm), the helmet's dust reduction 
efficiency decreased significantly, averaging only 49 percent, which is 
equivalent to an EPF of 2.
    Other researchers have reported that helmeted PAPR systems are 
vulnerable to inward leakage into the wearer's breathing zone (Howie, 
et al., 1987; Sherwood, 1991). For example, Howie, et al., found that 
increasing airflow velocities from approximately 400 to 800 fpm doubled 
the inward leakage of the helmet when the airflow impinged on the 
wearer's head only, and increased the leakage further when the airflow 
impinged on the wearer's body and head (Howie, 1987). Subsequent 
testing of a redesigned unit at a wind velocity of approximately 700 
fpm showed decreased inward leakage, yielding a protection factor of 
6.3. This met the target protection factor of 5, which was subsequently 
proposed by the European Community to be the standard for powered 
helmet respirators.
    More recent studies conducted by Bhaskar, et al. (1994) at four 
medium-velocity western longwalls indicated loose-fitting PAPRs had an 
average dust reduction efficiency of 83.8 percent (Ibid.). Although a 
different sampling procedure was used, this result is consistent with 
the average value of 84 percent obtained by Cecala, et al., under 
normal mine face-velocity conditions. During the test period, the 
headgate velocity ranged from 345 to 500 fpm, with approximately 88 
percent of the recorded velocities falling below 500 fpm. The tailgate 
velocities ranged from 280 to 550 fpm and only one exceeded 500 fpm. No 
tests were conducted under high mine face-velocity conditions.
    The headgate and tailgate velocities observed by MSHA inspectors at 
55 longwall MMUs were reviewed in 1999. The headgate and tailgate 
velocities ranged from 365 to 1,645 fpm and from 200 to 1,400 fpm, 
respectively. More importantly, headgate velocities at 60 percent of 
the MMUs exceeded 500 FPM and some 18 percent exceeded 800 fpm. 
Approximately 55 percent of tailgate velocities exceeded 500 fpm and 11 
percent exceeded 800 fpm.
    PAPRs have been demonstrated to be effective on longwall MMUs when 
air velocities do not exceed 500 fpm, but, as described above, there is 
evidence that their effectiveness is reduced when air velocities are 
increased. Therefore, given the range of observed longwall face air 
velocities to which miners are exposed and the proposed requirement 
that the verified ventilation plan demonstrate that the longwall 
shearer operator (occupation code--044) be at or below the applicable 
standard, MSHA is proposing to grant a protection factor of two for 
loose-fitting PAPRs used under this proposal. Multiplying either the 
respirable dust standard or the verification limit (whichever is 
applicable) by the protection factor yields the maximum concentration 
of respirable dust against which a particular type of respirator can be 
used. In other words, if MSHA permits a longwall operator to use PAPRs, 
then the maximum concentration of respirable coal mine dust and quartz 
dust against which these particular respirators can be used are 4.0 mg/
m\3\ and 200 g/m\3\, respectively. A complete respiratory 
protection program is required to assure that a respirator's protective 
value is not compromised by improper fitting or usage.
    MSHA's determination is based on the best scientific and technical 
information available as well as sound engineering judgment. However we 
encourage you to submit comments on the protection factor. We are 
particularly interested in obtaining more recent data that may be 
available concerning protection factors as well as the conditions for 
the use of PAPRs. If you believe MSHA should establish a different 
protection factor, please submit these data supporting your position.

E. Guidelines for Determining What Is a Feasible Dust Control

    The proposal would require a mine operator to implement all 
feasible engineering or environmental controls that are technologically 
and economically feasible. The Federal Mine Safety and Health Review 
Commission (Commission) has addressed the issue of what MSHA must 
consider, when determining what is a feasible control for enforcement 
purposes. In cases involving the noise standard for metal and nonmetal 
mines, the Commission has held that a control is feasible when it: (1) 
reduces exposure, (2) is economically achievable, and (3) is 
technologically achievable. See Secretary of Labor v. Callanan 
Industries, Inc., 5 FMSHRC 19 00 (1983), and Secretary of Labor v. A. 
H. Smith, 6 FMSHRC 199 (1984).
    In determining technological feasibility of an engineering control, 
the Commission has ruled that a control is deemed achievable if through 
reasonable application of existing products, devices, or work methods 
with human skills and abilities, a workable engineering control can be 
applied to the exposure source. The control does not have to be ``off-
the-shelf'' or already available but, it must have a realistic basis in 
present technical capabilities. Further, the Commission has held that 
MSHA must assess whether the cost of the control is disproportionate to 
the ``expected benefits,'' and whether the cost is so great that it is 
irrational to require its use to achieve those results. The Commission 
has expressly stated that cost-benefit analysis is unnecessary in order 
to determine whether an engineering control is feasible. According to 
the Commission, an engineering control may be feasible even though it 
fails to reduce the exposure to permissible levels in the standard, as 
long as there is a significant reduction in exposure.
    Consistent with the Commission case law, MSHA would consider three 
factors in determining whether engineering or environmental controls 
are feasible at a particular mine: (1) the nature and extent of the 
overexposure; (2) the demonstrated effectiveness of available 
technology; and (3) whether the committed resources are 
disproportionate to the expected results. As explained in the 
discussion of proposed Sec. 70.211 in Section IV of the

[[Page 42138]]

proposal, the formal determination of whether all feasible engineering 
or environmental controls have, in fact, been implemented at a specific 
mine to prevent excessive dust concentrations would be made by the 
Administrator for Coal Mine Safety and Health based on the best 
available information, experience, and engineering judgment.

F. Application of Continuous Monitoring Technology to Prevent 
Overexposures on Individual Shifts

    Because approved technology that continuously monitors respirable 
dust and displays dust concentrations in real-time is not available, 
effective ventilation plans remain the only practical means to provide 
reasonable assurance, on a continuous basis, that miners are not 
overexposed on individual shifts. However, MSHA recognizes that person-
wearable continuous respirable dust monitors under development may lead 
to significant improvements in monitoring the work environment in order 
to improve miner health protection. In an effort to reduce occupational 
respiratory disease among underground coal miners, MSHA encourages mine 
operators to adopt new and better dust monitoring technology as part of 
the approved ventilation plan.
    Unlike the current monitoring system, which relies on periodic 
sampling and requires that corrective action be taken after the 
necessary delay in obtaining dust level information, continuous 
monitoring would allow mine operators and miners to be aware of the 
actual dust conditions at all times, thereby enabling immediate action 
to avert possible overexposure. The ability to monitor dust exposure 
continuously during the shift, predict end-of-shift cumulative 
exposures, and to display the actual end-of-shift exposure would be far 
more effective in preventing simple CWP and PMF than the current 
system.
    The health benefits of continuous monitoring were clearly 
recognized by both the Task Group and the Advisory Committee. Both 
recommended development, field testing, and immediate deployment of 
such monitors for a variety of purposes. The Task Group concluded that 
continuous monitoring of the mine environment and dust control 
parameters offered the best long-term solution for improving the 
existing federal program designed to prevent simple CWP and PMF among 
coal miners. Similarly, the Advisory Committee stated in its report 
that:

    Worker exposure to excessive levels of dust can be prevented by 
implementing a hazard surveillance program that provides mine 
personnel with current information on actual dust levels in the work 
environment at all times, and on the status of key dust control 
parameters. The availability of this information on a real-time 
basis would enable mine personnel to focus attention immediately on 
the need to adjust control parameters to avert possible 
overexposure. The recent development of continuous dust and 
continuous dust control parameter monitors, which have both direct 
reading and data recording/processing capabilities, offers the 
potential to improve monitoring of the work environment 
significantly and contribute to the effective control of exposure. 
(MSHA, 1996).

    MSHA has sought a means to measure the concentration of respirable 
coal mine dust in coal mines on a continuous basis for nearly two 
decades. Beginning in the 1970's, at the request of MSHA, the former 
U.S. Bureau of Mines funded several developments of fast-response, 
direct-readout respirable dust monitors for measuring the concentration 
of respirable dust.
    One type of fast-response respirable dust monitor determined the 
mass of respirable dust particles collected on a grease-coated disk by 
the attenuation of beta radiation caused by the dust spot on the 
impaction disk. The unit was capable of operating for long periods, 
taking up to 450 1-minute samples, and printing the individual and 
time-integrated concentrations on a tape.
    Other devices have used light-scattering technology to measure and 
provide an immediate direct readout of dust concentrations. Since light 
scattering is often dependent on particle characteristics such as size, 
surface properties, and refractive index, this type of dust monitor 
does not measure a mass concentration directly and can provide only a 
relative measurement. However, it can be calibrated in the laboratory 
to give an approximate mass concentration.
    The light-scattering technology was later incorporated in a 
machine-mounted, continuous respirable dust monitor for use in 
underground mines. In the early 1980's, however, it was determined that 
this technology was not effective for monitoring compliance with the 
applicable dust standard. Nevertheless, instruments which used the 
light scattering principle were found to be useful tools to locate dust 
sources and to determine its magnitude. Such instruments continue to be 
especially useful for evaluating dust-control techniques such as dust 
collectors and water sprays that can be turned on and off quickly and 
repeatedly.
    The 1992 Task Group report recommended the accelerated development 
of a fixed-site underground dust monitor, capable of providing 
continuous information on dust levels and personal sampling devices 
capable of providing both short-term and full-shift exposure 
measurements. In response to this recommendation, the former Bureau of 
Mines, with MSHA's assistance, again evaluated existing technology that 
could be used in the development of a fixed-site underground mine dust 
monitor. This was made possible because of advances in sensing and 
electronic signal processing technology that had occurred since 
development of the first generation machine-mounted dust monitor in the 
late 1970's. Eventually a fixed site/machine-mounted continuous 
respirable dust monitor based on the proprietary mass-measurement 
technology known as the tapered element oscillating microbalance 
(TEOM) was developed and field tested.
    The TEOM technique is capable of continuously weighing a filter 
upon which dust is collected. It provides a real-time record and a 
permanent record of the total mass collected on the filter. The device 
can display the time-weighted average (TWA) concentration of respirable 
coal mine dust (total mass of dust collected divided by the length of 
time the unit was operated), the instantaneous (real-time) 
concentration, and the projected full-shift concentration. This would 
allow a mine operator to adjust control measures or optimize mining 
procedures to prevent miner overexposure. The full-shift concentration 
of respirable coal mine dust would be available at the end of the 
shift. The developer of the fixed-site monitor is also working on a 
person-wearable, end of shift/continuous respirable dust monitor using 
the same TEOM technology.
    In addition to the TEOM technology, NIOSH is developing another 
person-wearable device that has the potential for continuously 
monitoring the mine environment. This device measures the mass of 
respirable dust indirectly based on the amount of pressure drop 
detected across the collection filter.
    MSHA is seeking ways to encourage voluntary deployment of this 
technology, once it has been verified as reliable. MSHA has considered 
allowing mine operators to adopt a continuous personal monitoring 
strategy as part of the approved ventilation plan, in lieu of plan 
verification. Under this approach, the operator would have the 
flexibility of choosing from several technologies available for 
continuous personal monitoring. If an operator adopts continuous 
personal monitoring, the following additional information, at a

[[Page 42139]]

minimum, would be required for the mine ventilation plan:
    1. The specific continuous personal monitoring device the operator 
intends to use which has been approved by the Secretary;
    2. The DO and other occupations or individuals, including part 90 
miners, that will be sampled on every production shift and the length 
of the production shift to be sampled;
    3. The procedures for preventing exposure above the applicable dust 
standard;
    4. The manufacturer's calibration and maintenance requirements, and 
a description of how records of calibration and maintenance will be 
made available to MSHA, miners and the miner's representatives; and
    5. A description of how end-of shift measurements will be recorded, 
who will certify that such records are accurate and properly taken, how 
long such records will be maintained, where such records will be made 
available for inspection by MSHA, miners and the miner's 
representatives, and how miners will be notified on each production 
shift of the end-of-shift measurements.
    At the present time, we do not believe that technology to enable 
continuous monitoring of respirable dust has advanced to the point 
where it could be relied upon as an alternative to plan verification. 
In the future, when this technology is available, MSHA will consider 
the implementation of such an alternative to the proposed plan 
verification program. We request comments on this approach as a 
possible alternative to plan verification. MSHA is specifically 
interested in any proposals for the use of continuous personal 
monitoring, as well as any information which may be available 
concerning developing technology. Should an operator be interested in 
implementing a continuous personal monitoring program at a specific 
mine, MSHA will review the plan and consider development of a pilot 
program to develop information which may be useful for future 
rulemaking. MSHA is interested in comments concerning the specific 
provisions which should be included in the ventilation plan to assure 
that, if an operator does develop a continuous monitoring program, 
miners will not be overexposed on any individual shift.

IV. Discussion of Proposed Rule

A. Summary

    As recommended by the Advisory Committee in 1996, MSHA is proposing 
to assume responsibility for all compliance sampling for respirable 
dust in underground coal mines as required under CFR parts 70 and 90. 
This proposal includes revocation of bimonthly compliance sampling 
requirements, abatement sampling requirements, the process for 
establishing a reduced standard when quartz is present, and operator 
sampling requirements for miners who have evidence of the development 
of pneumoconiosis under part 90. In order to provide a greater level of 
protection than that provided under these sampling requirements, MSHA 
is proposing to require each underground coal mine operator to have a 
verified mine ventilation plan. Under this proposal, MSHA would verify 
the effectiveness of the mine ventilation plan for each mechanized 
mining unit (MMU) in controlling respirable dust under typical mining 
conditions.
    Mine ventilation plans have long been recognized as a means of 
addressing mine-specific health and safety issues. Existing Sec. 75.370 
requires that each mine operator design a ventilation plan to control 
methane and respirable dust in the mine. It further requires that the 
plan be suitable to the conditions and mining system at the mine. 
However, there is no current provision requiring the effectiveness of 
mine ventilation plans to be verified under typical mining conditions.
    Since 1970, beginning with enforcement of the Federal Coal Mine 
Health and Safety Act of 1969, the level of respirable dust in 
underground coal mines has been significantly reduced. Although much 
progress has been made, MSHA sampling data indicate that some work 
environments continue to have excessive concentrations of respirable 
dust. It is MSHA's position that excessive dust levels can be 
substantially reduced, if not eliminated, by implementing the Advisory 
Committee's recommendations to enhance plan quality and strengthen the 
plan approval process. Toward this end, this proposal would revise 30 
CFR by revising part 70, subparts A, B, and C amending two existing 
sections of part 75.
    This proposal would require evidence that the mine ventilation plan 
is effective in controlling respirable dust as required by Sec. 75.370. 
Within the first 30 days of operating a new MMU, or when required to do 
so by the District Manager, mine operators would have to specify the 
operating parameters of an effective plan and then MSHA would verify 
the plan's effectiveness based on a sufficient number of full-shift 
samples taken at designated locations.
    Under this proposal, we would collect full-shift respirable dust 
samples, called ``verification samples,'' to demonstrate the adequacy 
of the dust control parameters specified in the mine ventilation plan 
in maintaining the concentration of respirable coal mine and quartz 
dust at or below 2.0 mg/m\3\ and 100 g/m\3\, respectively.
    For purposes of plan verification, ``full-shift'' would refer to 
the entire work shift during which material is produced by an MMU. 
Currently, many mining operations have work shifts of more than 8 
hours. Miners working extended shifts should be protected from the 
hazards of respirable dust and quartz by the ventilation plan. 
Accordingly, the proposed verification samples would not be limited to 
8 hours or less, as under the current bimonthly operator sampling 
regulations.
    A sample would be valid for verification purposes only if the shift 
on which it was taken met certain requirements. This is necessary in 
order to verify that dust controls specified in the plan are sufficient 
to prevent excessive dust concentrations, even when a higher-than-
average amount of material is produced. The proposed operator's 
requirements for a shift used for verification sampling are:
    (1) The dust controls and work practices utilized must be those 
listed in the mine ventilation plan;
    (2) MSHA's measurements of the engineering or environmental control 
parameters must not exceed 115% of the quantities specified in the 
plan; and
    (3) The amount of material produced must be at least the 
``verification production level'' or VPL.
    The VPL is defined as the tenth highest production level recorded 
in the most recent 30 production shifts.
    The proposed rule would require mine operators to: (1) Set and 
maintain the dust control parameters during MSHA verification sampling 
at levels specified in the plan; (2) maintain and make available to 
MSHA records of the amount of material produced by each mechanized 
mining unit during each production shift; and (3) provide additional 
information in mine ventilation plans.
    The number of samples necessary to verify that the dust control 
parameters proposed for an MMU are effective would depend on the 
individual sample. Since all such measurements are subject to potential 
sampling and analytical errors, some of them may fall slightly below 
the verification limit even when the true concentration of respirable 
coal mine dust or quartz does not. Therefore, to ensure that the 
verification limits have actually been met, it is necessary to provide 
for a margin of error in each measurement.

[[Page 42140]]

The ``critical values'' established by MSHA provide this margin of 
error. If the VPL is achieved and dust concentrations are sufficiently 
low, the District Manager could approve a plan based on as few as one 
shift of sampling. However, if dust concentration measurements are 
higher, or if the actual production was less than the VPL MSHA would 
sample additional shifts.
    Consistent with the Mine Act and its implementing regulations, 
MSHA's longstanding policy has been to preserve the primacy of 
engineering controls, to the extent that they are technologically and 
economically feasible. Consequently, MSHA has not accepted the use of 
approved respiratory protection or administrative controls as a means 
of achieving compliance with the respirable dust standard. In order to 
provide all miners with the highest possible level of health 
protection, as intended by the Mine Act, MSHA is now proposing to 
permit the use of approved PAPRs or verifiable administrative controls 
to supplement engineering or environmental controls under certain 
circumstances for compliance purposes. Their use would be limited to 
longwall mining operations and permitted only after MSHA has 
determined, upon request of the operator, that all feasible engineering 
or environmental controls cannot maintain the mine atmosphere within 
applicable standards. In such cases, specific requirements governing 
the use of PAPRs or verifiable administrative controls would be 
specified in the mine ventilation plan.
    Finally, the proposal would require you to maintain, and make 
available to MSHA inspectors, records of the amount of material 
produced by each MMU during each production shift over a running six-
month period. This, along with routine bimonthly and other sampling 
data, would enable us to review the suitability of the plan parameters 
on an ongoing basis.
    Although a VPL would be included in the ventilation plan, we would 
not cite you for producing at levels exceeding the VPL. We would expect 
production on an MMU to exceed the VPL on about 33 percent of all 
production shifts. If the District Manager determines that your 
production exceeds the VPL on more than about 33 percent of the 
production shifts over a six-month period, then this may trigger the 
plan verification process using a higher VPL.
    These and other provisions of the proposed rule are explained in 
more detail in the following section-by-section discussion.

B. Section-by-Section Discussion

    This section of the preamble explains, section-by-section, the 
provisions of the proposed rule. The text of the proposed rule is 
included at the end of the document.

Section 70.2  Definitions

    The existing definitions of certified person, concentration, and 
designated area (DA) are being modified to more clearly convey the 
intended meaning under the proposal. These modifications reflect 
necessary changes as a result of the removal of existing paragraphs and 
the transfer of other paragraphs, as well as the addition of new 
references. The proposal also includes definitions of new terms to 
clarify the mine ventilation plan verification process as it applies to 
mechanized mining units (MMUs). Some of the definitions are for 
technical terms developed specifically for this proposal, such as 
``verification limit'' and ``verification production level.'' Finally, 
the definitions of ``certified person,'' ``normal production shift,'' 
and ``valid respirable dust sample'' would be removed.
    We explain these new and revised definitions of terms below. You 
should also closely examine each proposed section where the term is 
used to review the context in which it is used.
    The following existing definitions are being modified:

Concentration

    The existing definition would be modified so that ``concentration'' 
refers to an 8-hour Mining Research Establishment (MRE) equivalent 
measure of the amount of sampled material contained per unit volume of 
air. The proposed revision would include the constant factor of 1.38 
which the Secretary currently uses to convert concentration of 
respirable dust measured with approved sampling devices to an 
equivalent concentration as measured with an MRE instrument.
    MSHA developed the existing coal mine dust standards from 8-hour 
shift exposure measurements. Therefore, if you take a sample over a 
period other than eight hours, you must adjust the concentration 
measurement to be equivalent to an eight-hour exposure. This will 
protect miners working shifts longer than eight hours, and would be 
accomplished by multiplying the sampler flow rate by 480 minutes, 
regardless of the length of time during which the sample was actually 
collected. (In these examples, to determine equivalent concentrations 
of respirable coal mine dust: MRE equivalent concentration (mg/m\3\)=
[GRAPHIC] [TIFF OMITTED] TP07JY00.001

where: rate of sampling = 0.002 m\3\/min).

    For example, suppose a DO sample is collected over a 9-hour shift 
that includes one hour of travel time. Suppose that the amount of dust 
accumulated during travel is negligible, and the amount of dust 
accumulated during production is 1.5 mg. If the concentration were not 
adjusted to an 8-hour equivalent, it would be diluted by the time spent 
traveling and calculated as 1.92 mg/m\3\. Under the proposed 
definition, the calculated concentration would be 2.16 mg/m\3\.
    The proposed definition does not change the daily limit on 
accumulated exposure intended by the existing exposure limit for coal 
mine dust. Since the current limit was based on an assumption that 
exposure occurs over an 8-hour shift, it corresponds to a daily 
cumulative exposure limit of 8  x  2.0 = 16 mg-hr/m\3\. The proposed 
definition of concentration would maintain this same MRE-equivalent 16 
mg-hr/m\3\ daily limit, regardless of the length of any shift worked.
    To continue the example, the exposure accumulated during a day is 
the same, whether from 8 hours at an average of 2.16 mg/m\3\ or from 9 
hours at an average of 1.92 mg/m\3\. In either case, the MRE-equivalent 
exposure accumulated for the day is 17.3 mg-hr/m\3\, which exceeds the 
intended daily limit of 16 mg-hr/m\3\. Under the proposed definition, 
this would be reflected by the fact that the calculated concentration 
exceeds 2.0 mg/m\3\. MSHA solicits comments on this method of adjusting 
concentrations to an 8-hour equivalent.

[[Page 42141]]

Designated Area (DA)

    The existing definition would be modified to permit the Secretary 
to identify designated areas and to remain consistent with existing 
procedures which have been in effect since 1980. Once identified, the 
location of these DAs and the respirable dust measures to be used at 
the dust generating sources for these locations must be contained in 
the operator's mine ventilation plan as provided for under 
Sec. 75.371(t). However, the operator would not be required to sample 
these DA's under the proposal. MSHA is also proposing to transfer the 
requirement for identifying each DA specified in existing 
Sec. 70.208(e), which will be removed, to revised Sec. 70.2(e).

Mechanized Mining Unit (MMU)

    The existing definition would be modified by removing 
Sec. 70.207(e) (Bimonthly sampling; mechanized mining units) which will 
be deleted, and revising Sec. 70.207; and by transferring the 
requirements for identifying each MMU specified in existing 
Secs. 70.207(f)(1) and (f)(2), to revised Sec. 70.2(o).

Quartz

    The existing definition of quartz would be modified by specifying 
the analytical method that MSHA has been using since 1983 to determine 
the quartz content of respirable dust samples. The reason for this 
modification is to standardize the procedure, thereby enabling other 
laboratories to reproduce quartz determinations made by MSHA.
    The following new definitions are being proposed:

Critical Value

    ``Critical value'' would mean the maximum acceptable full shift 
dust concentration measurement demonstrating that the applicable 
verification limit has been met at a high level of confidence. Appendix 
A explains how each critical value was derived. The specific critical 
values and their use are detailed in Secs. 70.209 and 70.213.

Dust Control Parameters

    ``Dust control parameters'' would mean the respirable dust control 
requirements of a mine ventilation plan, including engineering or 
environmental controls, maintenance procedures, and any other 
requirements described in a ventilation plan. These requirements are 
intended for the protection of miners from excessive levels of 
respirable dust and must be in place on every production shift. To 
assure compliance with the ventilation plan, you must check the dust 
control parameters on each MMU before beginning production, as required 
under Sec. 75.362(a)(2). This term has not been formally defined until 
now.

Engineering or Environmental Controls

    ``Engineering or environmental controls'' would mean all methods 
that control the level of respirable dust in the work environment by 
either reducing dust generation or by suppressing, diluting, capturing 
or diverting the dust being generated during the mining process. 
Throughout the proposal, the terms ``engineering'' and 
``environmental'' controls are used interchangeably. The 
Racal Airstream helmet (or the 3M\TM\ Airstream\TM\ Helmet-
Mounted PAPR), or any other respiratory protective device approved and 
labeled as such by the National Institute for Occupational Safety and 
Health (NIOSH), is not defined as an engineering or environmental 
control.

Full Shift

    ``Full shift'' is defined differently for purposes of plan 
verification and abatement sampling, and for bimonthly compliance 
determinations. For purposes of abatement and plan verification, ``full 
shift'' would mean an entire work shift, including travel time to and 
from the MMU. Because of the way MSHA intends to define 
``concentration,'' this would be equally protective regardless of the 
production and travel times. For example, suppose miners at one MMU 
travel for one hour and mine for eight hours. Miners at another travel 
for two hours and also mine for eight hours. Suppose, further, that the 
dust concentration during travel is negligible and that the dust 
concentrations are identical during production at the two MMUs. Then 
the amount of dust accumulated on a filter will be the same, say 1.0 
mg, in both cases. Applying the proposed definition, the dust 
concentration calculated for both MMUs would be 1.44 mg/m\3\.
    For purposes of bimonthly compliance determination, MSHA would 
continue its current practice of limiting sampling to a 480-minute 
maximum. MSHA solicits comments on whether ``full shift'' for 
compliance sampling purposes should be defined in the same way as for 
abatement and plan verification purposes. MSHA also solicits comments 
on whether ``full shift'' should be defined, as proposed, in the same 
way for abatement and plan verification purposes.

Material Produced

    ``Material produced'' would mean the total amount of coal and/or 
other substance extracted by an MMU during any production shift. In 
order to properly assess the effectiveness of the mine ventilation plan 
requirements for respirable dust control and for subsequent monitoring 
purposes, MSHA proposes to require that the operator record and make 
available records of the amount of material produced by each MMU each 
shift under a new paragraph (h) of Sec. 75.370.

MRE

    ``MRE'' would mean Mining Research Establishment of the National 
Coal Board, London, England.

Powered Air-Purifying Respirators (PAPRs)

    ``Powered, air-purifying respirators (PAPR)'' would mean a NIOSH 
approved loose-fitting respirator that uses a blower to force the 
ambient air through air-purifying elements to deliver filtered air to 
the miner's breathing area. Under the proposal, an operator who employs 
longwall mining has the option of using either powered, air-purifying 
respirators (PAPRs) or verifiable administrative controls as a 
supplemental means of control once MSHA has determined that 
concentrations of respirable dust have been reduced as low as is 
feasible with engineering and environmental controls. This may include 
RACAL Airstream helmets or similar devices that are available 
now or in the future. The reason for excluding other types of approved 
respirators is discussed in section II.B.1.

Verifiable Administrative Control

    ``Verifiable administrative control'' would mean a work practice 
intended to reduce the miner's full shift exposure to respirable dust 
hazards by altering the way in which work is performed. Examples 
include rotation of miners to areas having lower concentrations of 
respirable dust, rescheduling of tasks, and modifying work activities 
to reduce exposure. A ``verifiable administrative control'' must be (1) 
capable of review to confirm proper implementation; (2) clearly 
understood by miners; and (3) applied consistently over time.

Verification Limits

    ``Verification limits'' would mean the maximum dust concentration 
for which the ventilation plan has been verified as effective in 
maintaining during the full shift. There are two separate verification 
limits: An MRE-equivalent concentration of 2.0 mg/m\3\ for respirable 
coal mine dust and an MRE-equivalent concentration of 100 g/
m\3\ for respirable quartz dust. Both of these

[[Page 42142]]

limits apply to dust concentrations measured over a full shift.
    MSHA does not enforce a separate standard for quartz dust. It 
regulates exposures to quartz and coal mine dust by reducing the 
applicable standard for coal mine dust, by means of a formula, when 
quartz content of the respirable dust is above 5 percent. This formula 
(10 divided by the concentration of quartz, expressed as a percentage) 
establishes an applicable coal mine dust standard that, in effect, 
limits quartz concentrations in the mine environment to no more than 
100 g/m\3\. For example, when the quartz content is 5 percent, 
the applicable standard is 2.0 mg/m\3\; when the quartz content is 10 
percent, the applicable standard is 1.0 mg/m\3\. Five percent of 2.0 
mg/m\3\ and 10 percent of 1.0 mg/m\3\ are each 0.100 mg/m\3\ or 100 
g/m\3\.
    The Advisory Committee recognized that a significant quartz 
exposure hazard continues to exist in coal mines, especially for 
operations such as roof bolting. Based on MSHA data, 66 percent of 
underground coal mines are operating on a reduced dust standard due to 
the respirable dust in the mine environment containing a high 
percentage of quartz. MSHA data also indicates that 73 percent of the 
over 600 roof bolters and over 29 percent of the MMUs sampled bimonthly 
by mine operators are operating under reduced dust standards. The 
number of reduced standards in effect indicates that a significant 
potential health risk due to quartz exposure continues to exist. Under 
the current program, miners can be exposed to excessive quartz levels 
while the dust standard-setting process takes place. For example, 
consider a recent situation where an MSHA dust sample of a roof bolter 
was 0.9 mg/m\3\; a level that was in compliance with the applicable 
standard, 1.3 mg/m\3\. However, when the sample was analyzed for quartz 
the results indicated that the actual concentration of quartz dust in 
the mine environment exceeded 270 g/m\3\; or more than two and 
a half times above the permissible level of 100 g/m\3\. The 
only action that could be taken in this particular situation was to 
initiate the dust standard-setting process, which, on average, can take 
at least one month or longer. The existing standard-setting process 
continues from the time the operator is cited for violating the reduced 
standard through the time MSHA enforces final corrective action.
    Under this proposal, MSHA would require operators to anticipate the 
potential for quartz exposure and to incorporate controls prior to 
approval of the mine ventilation plan. In order to verify that the 
operator has incorporated such controls, MSHA would determine the mass 
of quartz contained in each verification sample and express the 
concentration of quartz in the mine air as an airborne concentration 
and not as percent quartz in the dust during the verification process.
    This process would require operators to address both the potential 
for respirable coal mine dust and quartz dust exposure. As recommended 
by the Advisory Committee, the proposed plan verification process would 
establish a monitoring and compliance framework to aid MSHA and the 
coal mine operator in targeting mining situations where quartz exposure 
constitutes a significant hazard and enhanced dust control procedures 
are required.

Verification Production Level (VPL)

    The ``VPL'' would mean the tenth highest production level recorded 
in the most recent 30 production shifts. It is an estimate of the 67th 
production percentile within an MMU. (Sec. 70.208 explains how to 
establish the VPL if you do not have records for 30 production shifts.)
    We believe that the production criteria used to evaluate plan 
effectiveness may not adequately represent typical conditions under 
which miners work. Requiring that plans be verified at or above this 
VPL would provide assurance that excessive dust concentrations would be 
avoided on a majority of production shifts. MSHA believes that using 
this VPL is more protective of miners' health than the current practice 
of evaluating plan adequacy based on MSHA inspector samples taken when 
production can be as low as 60 percent of the average production. We 
note however, that a VPL defined as a higher production percentile than 
is being proposed would likely assure that miners would be more 
protected on a majority of production shifts. The Agency welcomes 
comments on both the use of a VPL and the appropriate production 
percentile to use to define it.
    Since approximately 50 percent of all production shifts are 
expected to exceed average production, it follows that the vast 
majority of all production shifts exceed 60 percent of average 
production. Therefore, by using 60 percent of average production as the 
lower range of the production criteria for plan evaluation purposes, as 
required under current inspection procedures, we have no assurance that 
the plan would be effective under the vast majority of production 
conditions.
    If you do not have records for 30 production shifts, you can use 
the minimum production actually achieved on a shift used to verify the 
plan's effectiveness as your VPL.

Verification Sample

    ``Verification sample'' would mean a sample collected for purposes 
of plan verification. In order to be valid the sample must be collected 
on a full shift during which the amount of material produced is at or 
above the VPL. Only those engineering or environmental controls and 
other measures listed in the mine ventilation plan may be employed, at 
levels not exceeding 115% of the quantities specified in the plan 
during the shift in which the sample is collected. For example, if the 
plan specifies an air quantity of 4,000 cfm, the quantity measured 
during verification must not exceed 4,600 cfm (4,000 cfm x 1.15 = 
4,600).

Section 70.100  What are the respirable dust standards when quartz is 
not present?

    MSHA is proposing no substantive changes to existing Sec. 70.100(a) 
and (b), except for removing the reference to Sec. 70.206 (Approved 
sampling devices; equivalent concentrations) from existing paragraphs 
(a) and (b) and replacing it with revised Sec. 70.2(c). The 
requirements of revised Sec. 70.2(c) are similar to the previous 
standard in Sec. 70.206. The proposal retains the respirable dust 
standard of 2.0 mg/m\3\ in existing paragraph (a) and the intake air 
standard for respirable dust of 1.0 mg/m\3\ in existing paragraph (b).

Section 70.101  What is the respirable dust standard when quartz is 
present?

    MSHA is proposing to retain the existing formula (10 divided by the 
concentration of quartz, expressed as a percentage) for reducing the 
respirable dust standard below 2.0 mg/m\3\ when the quartz content of 
the respirable dust in the mine atmosphere is above 5 percent. However, 
the Agency is proposing to change how it arrives at an average quartz 
percentage that is used to establish an applicable dust standard.
    MSHA recently published a proposed ``Program Policy Letter (PPL) on 
Samples Used to Determine the Respirable Dust Level When Quartz is 
Present'' for public comment [64 FR 65671, November 23, 1999] whereby 
the standard would be determined based solely on the results of 
multiple MSHA samples. Under this proposal, as in the PPL, MSHA would 
no longer be using a combination of MSHA and mine operator sampling for 
determining the average quartz percentage, which has been the practice 
since 1985. Instead, as discussed in section III.B, this proposal

[[Page 42143]]

would establish MSHA sampling as the exclusive basis for determining 
the reduced standard and require three valid MSHA samples to set a 
reduced standard. Since we are sampling underground mines bimonthly, we 
will have no difficulty in collecting the required number of samples to 
arrive at the average quartz percentage. We believe our samples will be 
more representative of the level of quartz to which miners are exposed 
than as determined currently. This increased level of sampling should 
also allay any operator concerns regarding the collection of 
``misleadingly high'' samples during atypical periods. We would also 
begin reporting quartz levels to the nearest tenth of a percent. This 
is intended to be more protective for the miner than under the current 
program of truncating results to the nearest full percent. We believe 
that the method for establishing reduced standards will be more 
protective for the miners than the current program.

Verification of Ventilation Plan Effectiveness.

    Existing Sec. 75.370 requires you to develop an underground coal 
mine ventilation plan that is designed to control methane and 
respirable dust in the mine. It further requires that the plan be 
suitable to the conditions and mining systems at the mine. Proposed 
Secs. 70.201 to 70.211 sets forth the steps that MSHA will follow to 
demonstrate that your mine ventilation plan required by Sec. 75.370 is 
effective in controlling respirable dust under typical mining 
conditions. This demonstration would be required before MSHA approves 
the mine ventilation plan.
    Under Secs. 70.201 to 70.211, MSHA would verify the effectiveness, 
for the control of respirable dust, of all mine ventilation plans 
submitted to the District Manager for approval under Sec. 75.370. To do 
this, MSHA would collect full shift samples, called ``verification 
samples.'' For MSHA to approve the plan, these samples would have to 
demonstrate that the plan's dust control parameters are effective in 
maintaining concentrations of respirable coal mine dust and quartz dust 
in the working environment of MMUs at or below 2.0 mg/m\3\ and 100 
g/m\3\, respectively, under typical mining conditions.
    MSHA has drafted the regulatory text of this proposal in a question 
and answer format. The remainder of the Section-by-Section discussion 
also follows this format. As discussed in Chapter IV paragraph A below, 
we request your comments on this format.

Section 70.201  Who must have a verified ventilation plan?

    Section 75.370 requires all underground coal mine operators to 
submit a mine ventilation plan for approval. The proposed Sec. 70.201 
would require the verification of these plans in terms of their 
effectiveness in controlling dust.

Section 70.202  What is a verified ventilation plan?

    A ventilation plan submitted under Sec. 75.370 must be designed to 
control respirable dust and must be suitable to the conditions and 
mining systems at the mine. In order for the plan to be verified under 
this proposal, the plan's dust control parameters must be demonstrated 
to be effective, at a high level of confidence, in maintaining the 
concentration of respirable coal mine dust and quartz dust in each MMU 
at or below 2.0 mg/m\3\ and 100 g/m\3\, respectively. This 
demonstration would be based on MSHA full shift verification samples, 
which are collected when the amount of material produced is at or above 
the VPL and only the engineering or environmental controls and other 
measures included in the ventilation plan are in place, at levels not 
exceeding 115% of the quantities specified in the plan.

Section 70.203  What will trigger the plan verification process?

    There are several ways in which the plan verification process could 
be initiated. You would trigger the process by submitting a new 
ventilation plan under Sec. 75.370, or amending a previously approved 
ventilation plan under Sec. 75.371(f). The verification process could 
also be triggered if the District Manager requires you to change your 
plan after determining that your dust control parameters are no longer 
effective. Finally the verification process could be triggered if you 
propose revisions to a previously verified ventilation plan and the 
District Manager determines that the proposed revisions may cause the 
plan to be inadequate.
    Once your ventilation plan has been verified as effective, it 
should not be necessary to reverify your plan every six months. 
However, you may be required to change your plan parameters based on 
(1) results of the MSHA six-month review of the ventilation plan as 
required by Sec. 75.370(g), (2) excessive dust concentrations measured 
by MSHA sampling, or (3) a new reduced applicable dust standard which 
is less than the highest respirable coal mine dust concentration that 
was previously used to verify the plan. For example, if you are cited 
by MSHA for exceeding the applicable dust standard the District Manager 
may have cause to question the adequacy of the previously-approved 
plan.
    Also, depending on sampling results and production records, if your 
production exceeds the VPL during MSHA sampling, the District Manager 
may require you to verify the ventilation plan at the higher production 
level. For example, suppose your VPL is 10,000 tons and all five MSHA 
concentration measurements exceed the applicable standard on a shift 
for which the production is 12,000 tons. Then, if your production 
records indicate that you have exceeded the VPL on more than 33 percent 
of all production shifts during the previous six months, MSHA would 
initiate the verification process.

Section 70.204  When will MSHA conduct verification sampling?

    The District Manager will notify you of the schedule for 
verification sampling after granting provisional approval of your 
ventilation plan. However, before you receive provisional approval, you 
may be required to change your plan if the District Manager determines 
that your dust control parameters are inadequate or unsuitable for the 
current mining conditions. If provisional approval is not granted, you 
may not operate the affected MMUs. Since more than 700 existing mine 
ventilation plans may require verification, MSHA will not be able to 
verify all plans immediately. Under proposed Sec. 70.204 the District 
Manager would notify you of the date when MSHA intends to collect 
verification samples.

Section 70.205  What must I (the operator) do to comply this standard?

    When the District Manager notifies you that your mine has been 
scheduled for verification sampling, you would need to make sure that 
all the dust control parameters specified in your ventilation plan are 
fully implemented. Since the objective of plan verification is to 
determine the effectiveness of the plan's dust control parameters in 
controlling respirable dust under typical mining conditions, paragraph 
(a) would require you to utilize only the dust control parameters 
listed in the ventilation plan that was provisionally approved by the 
District Manager. On the date scheduled for verification sampling, you 
should establish production levels at or above the VPL specified in the 
plan, using only the dust control parameters and other measures listed 
in the plan.

[[Page 42144]]

    Recognizing that engineering or environmental controls such as air 
quantity and velocity are subject to measurement error and cannot 
easily be controlled with absolute precision, MSHA would allow the 
measured levels to be up to 115% of the levels specified in the plan. 
If, on the date of verification sampling, a measured quantity exceeds 
the corresponding quantity specified in the plan by more than 15 
percent, you will have the option to either (1) adjust the parameter(s) 
to what is specified in the plan before verification sampling begins or 
(2) make no adjustment to the parameter(s) prior to verification 
sampling. Under the second option, plan approval will be contingent on 
incorporating into your plan the maximum values of parameters in effect 
during verification sampling. If verification samples were taken when a 
parameter measurement exceeded 115 percent of the level specified in 
the plan, then (assuming none of the verification samples exceeded the 
critical values) that parameter quantity, as measured, would be 
incorporated in the plan ultimately approved by the District Manager.
    As of the effective date of the final rule, you would be required 
to begin maintaining records of the amount of material produced by each 
MMU during each shift. This would enable you to establish the 
``verification production level'' (VPL)--the minimum production level 
at which you must demonstrate the plan's effectiveness.
    Before you submit a previously approved ventilation plan to the 
District Manager for review and approval, proposed paragraph (c) would 
require you to provide additional information. This additional 
information is described under Sec. 75.371(f) of this proposal.
    To enable us to maximize our inspection resources and to promote an 
orderly verification process, proposed paragraph (d) would require you 
to notify the District Manager in a timely manner if you are unable to 
meet the conditions for verification sampling on the scheduled date. 
Failure to provide notification may be cause for revocation of the 
provisional approval of your ventilation plan.
    In accordance with section 103(f) of the Mine Act and the 
recommendations of the Advisory Committee, miners and their 
representatives would be provided the same walkaround rights during 
plan verification sampling as they are provided during any other 
physical inspection made pursuant to the provisions of section 103(a) 
by an authorized representative of MSHA.
    MSHA believes that under the guidance of the Interpretive Bulletin 
(43 FR 17546, April 25, 1978) these rights arise when: (1) An 
``inspection'' is made for the purposes set forth in section 103(a), 
and (2) the inspector is physically present at the mine to observe or 
monitor safety and health conditions as part of direct safety and 
health enforcement activity.
    The process of plan verification sampling is necessary to obtain 
information related to approval of the mine's ventilation plan and 
whether coal mine dust will be adequately controlled to protect miners 
health. Consequently, miners and their representative would have the 
right to accompany the inspector with no loss of pay for the time 
during which the representative exercises this right. However, this 
right is limited by Section 103(f) to only one such representative of 
miners.

Section 70.206  Who will MSHA sample and where will MSHA place the 
sampling device(s) when conducting verification sampling?

    MSHA will sample specific occupations within an MMU to demonstrate 
your plan's adequacy. These occupations would be selected because, 
based on past experience, within an MMU they would likely be exposed to 
the highest respirable coal mine dust concentration and, therefore, 
would be at greatest risk of overexposure. Therefore, MSHA would sample 
the environment of the DO (as under existing Sec. 70.207), the roof 
bolter operator(s) (occupation codes--012, 014 or 046), the longwall 
jack setters (occupation code--041), and any other occupation that the 
District Manager may designate for sampling after reviewing your 
ventilation plan.

Section 70.207  How many shifts will MSHA sample to verify my 
ventilation plan?

    This proposed section would explain that the number of shifts 
required to verify your ventilation plan would depend on two factors: 
first, the actual operating conditions during the shift that is 
sampled; and, second, the sample results. To qualify as a verification 
sample, the amount of material produced by the MMU must equal or exceed 
the VPL, and the dust control parameters must be at levels not 
exceeding 115 percent of the quantities specified in the plan. 
Therefore, the number of shifts depends largely on how quickly and 
consistently you are able to achieve these operating conditions. We may 
need to sample several production shifts before the production level on 
any single shift qualifies for verification purposes. We may verify the 
plan based on this single shift--but only if all concentration 
measurements on the sampled shift are at or below the appropriate 
critical values proposed in Sec. 70.209. This would demonstrate the 
plan's effectiveness at a high level of confidence. If any of the 
measurements exceed the appropriate critical value, then we would 
collect verification samples taken on one to three additional shifts, 
depending on the concentrations measured on those shifts. Since these 
additional shifts must also meet the criteria for production, and use 
only the engineering or environmental controls and other measures 
specified in the ventilation plan, we may have to sample a total of 
more than four shifts.
    Assuming that you make no special effort to meet the VPL during 
verification sampling, there is a 67-percent probability that a 
randomly selected production shift would not meet the VPL. 
Consequently, if you made no special production effort, there would be 
a 13-percent chance we would need to sample more than five shifts and a 
1.7-percent chance we would have to sample more than 10 shifts. \8\ On 
the other hand, again assuming no special production effort, there 
would be a 98-percent chance we would need 10 or fewer shifts and a 70-
percent chance that we would need three or fewer shifts. \9\ This 
assumes that the dust concentration measurement for each shift does not 
exceed the critical value corresponding to the number of shifts 
sampled. If you make a special effort to achieve high production on the 
sampled shifts, then fewer shifts would be required.
---------------------------------------------------------------------------

    \8\ Assuming no special production effort, the probability of 
needing more than n shifts to be sampled before you met the minimum 
production level required to verify the plan: P(X>n)= (.667) \n\; 
for example, the probability of more than 10 shifts being needed, 
P(X>10) = (.667) \10\ = 1.7 percent.
    \9\ Assuming no special production effort, the probability of 
needing n or fewer shifts to be sampled before you met the minimum 
production level required to verify a plan: 
P(Xn)=1-P(Xn); for example, the probability of 
10 or fewer shifts being needed, (1-(.667) \10\) = 98 percent.
---------------------------------------------------------------------------

Section 70.208  What if 30 shifts of production data are not to 
establish the verification production level (VPL)?

    If you are starting a new MMU or mine, you may not have 30 shifts 
of production data available when you submit a new ventilation plan. In 
such cases, proposed Sec. 70.208 requires you to establish the VPL as 
the minimum production level actually achieved on a shift used to 
verify the plan's effectiveness. For example, assume we initiate 
verification sampling of your longwall MMU. Based on the dust

[[Page 42145]]

concentration measurements obtained on the first shift sampled, your 
MMU happens to exceed either 1.85 mg/m\3\ for respirable coal mine dust 
or 93 g/m\3\ for quartz dust but not the verification limits. 
According to the applicable critical values table in Sec. 70.209, we 
would need to sample at least two more shifts to verify your plan's 
effectiveness, provided that no sample exceed 1.93 mg/m\3\ for 
respirable coal mine dust or 97 g/m\3\ for quartz dust. Assume 
that the highest production level was achieved on the third shift 
sampled and the dust concentration measurements obtained on that shift 
were low enough, according to the applicable critical values table in 
Sec. 70.209, to verify plan effectiveness based on a single shift. In 
this case, you would establish a VPL equal to the production achieved 
on that shift. If, on the other hand, the dust concentration 
measurements obtained on the third shift with the highest production 
level were not low enough to verify the plan on a single shift and a 
determination of the plan's adequacy was based on these three shifts, 
your VPL would be the minimum production achieved during verification 
sampling. In any case, the VPL would become part of your ventilation 
plan.

Section 70.209  When will MSHA approve my ventilation plan?

    This is a new section that proposes ``critical values'' that the 
District Manager would use to determine whether your plan's dust 
control provisions should be approved. These critical values, which 
differ according to the number of shifts used for verification, are 
listed in Table IV-1. When verification sample results do not exceed 
the appropriate critical value for respirable coal mine dust or quartz 
dust, we can be confident that the engineering or environmental 
controls in place during verification sampling successfully prevented 
excessive dust concentrations at the sampled locations. Therefore, MSHA 
would approve your plan when the dust control parameters are in place 
during verification sampling and none of the measurements obtained from 
your verification samples exceeded the appropriate critical value. 
Appendix A explains how the critical values were derived.

    Table IV-1.--Critical Values for Verifying Plan Effectiveness. The
 Result of Each Verification Sample Collected Must Be Less Than or Equal
                    to the Appropriate Critical Value
------------------------------------------------------------------------
                                                Critical      Critical
                                                value for     value for
    Number of shifts meeting criteria for       coal mine    quartz dust
            verification sampling              dust  (mg/   (g/
                                                  m\3\)         m\3\)
------------------------------------------------------------------------
1...........................................          1.71            87
2...........................................          1.85            93
3...........................................          1.93            97
4 or more...................................          2.0            100
------------------------------------------------------------------------

    The proposed approval process would allow the District Manager to 
base verification sampling on a reasonably small number of shifts, 
while maintaining a high level of confidence that approved ventilation 
plans adequately prevent excessive dust concentrations. We would have 
to sample at least one full shift under the operating conditions 
specified in the mine ventilation plan before we could make any 
determination of the plan's adequacy. The plan would be approved if all 
samples on that shift meet the criteria for a verification sample as 
defined in Sec. 70.2, and none of the sample results exceed the 
appropriate critical value for a single shift listed in Table IV-1. 
However, if any verification sample resulted in a coal mine dust 
measurement greater than 1.71 mg/m\3\ or a quartz dust measurement 
greater than 87 g/m\3\, samples would be taken on additional 
shifts.
    The following two examples illustrate how we would determine if 
your plan's dust control provisions should be approved:

    Example 1: Suppose samples were taken on two shifts. We would 
approve the dust control provisions of your plan if all quartz and 
coal mine dust measurements obtained on the two shifts were less 
than 1.85 mg/m\3\ or 93 g/m\3\, respectively. On the other 
hand, if one of the roof bolter samples resulted in a quartz 
concentration measurement of 95 g/m\3\, then we would not 
approve your plan, based on these two shifts alone. Instead, at 
least one additional shift would be needed. Verification samples 
from only one additional shift would be sufficient if none of the 
coal mine dust measurements on that shift exceeded 1.93 mg/m\3\, and 
none of the quartz measurements exceeded 97 g/m\3\. (Dust 
control parameters and production on this additional shift, as well 
as on the first two shifts, would need to meet the criteria for 
verification samples in proposed Sec. 70.2 (bb).)
    Example 2: Suppose verification samples were taken on four or 
more shifts. We would approve the dust control provisions as 
proposed if no measurement exceeded 2.0 mg/m\3\ of coal mine dust or 
100 g/m\3\ of quartz dust.

Section 70.210  What must I (the operator) do if one or more 
verification samples exceed either verification limit?

    This is a new section that would require you to take certain 
actions whenever a verification sample results in a measurement 
exceeding the verification limit for either respirable coal mine dust 
(2.0 mg/m\3\) or quartz dust (100 g/m\3\). You would be 
required to immediately identify the cause of the high dust 
concentration and prevent miners from being overexposed on subsequent 
shifts.
    When you receive notice from MSHA that you have exceeded either 
verification limit, you must immediately take corrective action. You 
must lower excessive respirable dust concentrations, so that none of 
your full shift measurements exceed verification limits in any of the 
identified occupational environments or sampling locations. At the same 
time, you must make approved respiratory equipment available to 
affected miners in accordance with Sec. 70.300.
    You would also be required to document the corrective actions taken 
for the District Manager, within five days of MSHA's notification that 
you have exceeded a verification limit. This documentation must 
describe all of your corrective actions, including proposed changes in 
dust control parameters. You would be encouraged to seek technical 
assistance from the District Manager to help you determine what 
additional corrective measures would be reasonably likely to reduce 
excessive dust concentrations.
    The District Manager will notify you if your ventilation plan is 
provisionally approved and when MSHA will again commence verification 
sampling. The District Manager may require you to make additional 
changes in your plan parameter(s) based on the results of verification 
sampling before starting sampling over again. If no changes are 
required, MSHA will continue

[[Page 42146]]

verification sampling from the point at which it stopped.
    The District Manager would choose, on a case-by-case basis, between 
resuming verification sampling or starting plan verification anew. MSHA 
would not necessarily require a revision of the ventilation plan nor 
start the ventilation verification process over again because a 
verification sample exceeded the verification limit by a small amount, 
such as 0.05 mg/m\3\. The decision to continue with your current 
ventilation plan or start over again with a new ventilation plan, would 
be based on the information you provide regarding the cause of any 
excessive dust concentration measurements and the steps you have taken 
to prevent similar occurrences in the future. For example, suppose dust 
concentration measurements are excessive due to a deviation in your 
established operating procedures. It should be possible for you to 
prevent such occurrences in the future without changing the ventilation 
plan. If the District Manager finds this to be the case, and accepts 
your proposed action to prevent similar occurrences, MSHA would resume 
verification sampling. However, the District Manager may determine that 
the ventilation plan is not adequate for current operating conditions 
and require you to change the plan parameters. If so, MSHA would start 
the verification sampling process over again.
    MSHA would not issue citations for exceeding verification limits 
during the plan verification process. However, MSHA will issue 
citations under proposed Sec. 70.210(a) for failure to take action 
required to address the cause of the excessive dust levels once you 
have been notified by MSHA.

Section 70.211  What if verification samples continue to exceed either 
verification limit even though I (the operator) believe all feasible 
engineering and environmental controls are in place?

    This proposed section would continue to require you to use all 
feasible engineering or environmental controls before implementing any 
supplemental means of control at longwall mining operations. For 
continuous and conventional mining operations MSHA would suggest 
additional engineering and environmental controls. Even if these 
controls do not prevent full shift respirable dust concentrations from 
exceeding the verification limits, you must continue to use them to 
reduce respirable dust to the lowest feasible level. Engineering or 
environmental controls have been the primary form of dust control for 
the past 30 years. The Advisory Committee recommended that engineering 
or environmental controls remain the primary means of protecting coal 
miners. Consistent with the Mine Act and the Advisory Committee's 
recommendation, under this proposal engineering or environmental 
controls continue to be recognized the primary means to control 
exposure to respirable dust.
    If you operate an MMU employing either a continuous or conventional 
mining method, we believe feasible engineering or environmental 
controls are available to control respirable dust to an acceptable 
level. Controls include better design of water spray systems for dust 
suppression and air movement, use of dust collectors, and improved face 
ventilation systems.
    Of approximately 800 continuous miner MMUs operating in over 500 
underground mines, over 90 percent employ extended cut techniques and 
are being operated remotely (Elam, August 1999). As a result, the 
continuous miner operator, the occupation normally identified as the DO 
for bimonthly sampling purposes, is no longer required to work close to 
the face area where material is being extracted.
    Roof bolting machines, a major generator of respirable quartz dust 
on continuous miner MMUs, must be equipped with suitable drill dust 
controls. Under Sec. 72.630, drill dust must be controlled by 
permissible dust collectors, by water, water with a wetting agent, by 
ventilation, or by any other method approved by MSHA.
    These and other approaches, as well as results of laboratory and 
field studies of the effectiveness of various dust controls, can be 
found in several detailed compilations prepared by the former U.S. 
Bureau of Mines, whose responsibilities have now been transferred to 
NIOSH. (U.S. Bureau of Mines various reports, undated). If you exceed 
either verification limit, the District Manager will suggest that you 
implement additional controls.
    As discussed in section II. B., MSHA recognizes that improvements 
in control technology have not kept pace with the increase in 
production technology associated with high-production longwall MMUs. 
Average longwall shift production reported during bimonthly sampling 
has increased from 890 tons per shift in 1980, to over 4900 tons per 
shift in 1999. Given the state of longwall dust control technology, the 
currently-available engineering or environmental controls may not 
succeed in sustaining continuous compliance at certain locations 
downwind of the longwall operator (occupation code--044) at some high-
production longwall MMUs under typical mining conditions.
    For your longwall operation, if you believe that you have 
implemented all feasible engineering or environmental controls, you may 
submit a written request to MSHA's Administrator for Coal Mine Safety 
and Health in Arlington, Virginia, to request for MSHA to review your 
longwall mining operation and determine if you have, in fact, 
implemented all feasible engineering controls.
    Upon receipt of such a request, MSHA would solicit guidance from a 
panel of experts which would be established for making such 
determinations. Members of this panel would have extensive knowledge in 
respirable dust control and would represent the following organizations 
within MSHA: Technical Support, Division of Health, the MSHA District 
having jurisdiction over your mine, and one other MSHA District. In 
some cases, we may solicit advice from NIOSH. As part of their 
deliberations, the expert panel may visit your mine to observe the 
various controls in operation. Any decisions reached by this panel 
would be based on the review of available information, their combined 
experience in dust control, and sound engineering judgement.
    If the Administrator determines that you are using all feasible 
engineering or environmental controls, we would notify you in writing 
that you have been granted approval to use either PAPRs approved under 
42 CFR 84 or verifiable administrative controls as a supplemental means 
of control to protect miners required to work downwind of the longwall 
operator. You would also be informed that the location of the DO would 
be changed from the 060 to the 044 occupation, or other occupation 
designated by the District Manager depending on how your longwall MMU 
is ventilated. You must continue to maintain the work environment of 
the new DO at or below the verification limits using engineering or 
environmental controls, as demonstrated during plan verification. As 
discussed earlier, while it may be difficult to make the environment 
safe for some miners working on the longwall face under certain mining 
conditions, MSHA believes that an acceptable work environment can be 
provided for the longwall operator (occupation code--044) and other 
miners on a continuing basis. You must choose either PAPRs or 
verifiable administrative controls for your ventilation plan. The 
notification would grant approval of an interim verification plan 
allowing the use of PAPRs or administrative controls as a

[[Page 42147]]

supplemental means of compliance. You must introduce additional 
engineering or environmental controls as they become available and 
feasible. Every six months, as part of our regular review of your mine 
ventilation plan, we would follow-up on your efforts to comply with 
this requirement.

Sections 70.212 through 70.215

Use of Approved Powered, Air Purifying Respirators

    These sections would establish the requirements for utilizing PAPRs 
to supplement engineering or environmental controls.

Section 70.212  For my longwall operation, what must I (the operator) 
do in order to use approved PAPRs to supplement engineering or 
environmental controls?

    This proposed section would require you to submit a revised 
ventilation plan to MSHA within five days of receipt of MSHA's written 
approval in accordance with Sec. 70.211 if you choose to use approved 
PAPRs to supplement engineering or environmental controls. Your revised 
plan must specify the engineering or environmental controls you believe 
are capable of maintaining respirable dust concentrations (1) at or 
below the verification limits in the environment of the new DO 
(previously occupation 060, and currently occupation 044 or another 
occupation designated by the District Manager), and (2) at or below two 
times the verification limits in the environment of any miner working 
on the longwall face (downwind of the DO) who is required to wear a 
PAPR.
    This is based upon the demonstrated effectiveness of PAPRs on 
longwall MMUs and the range of longwall air velocities observed by MSHA 
inspectors discussed earlier in section II.B.2, which led MSHA to 
reduce the protection factor assigned to loose fitting, helmeted PAPRs 
from 25 to two. In other words, the maximum full shift, MRE-equivalent 
concentration of respirable dust allowed in the environment of any 
miner working on the longwall face (downwind of the DO) who is required 
to wear a PAPR cannot exceed 4.0 mg/m\3\ of respirable coal mine dust 
and 200 g/m\3\ of respirable quartz dust.
    In addition to specifying all feasible engineering or environmental 
controls to be used, you would be required to include in your plan a 
written respiratory protection program for PAPRs for all affected 
miners as described in Sec. 72.710. MSHA's District Manager may require 
you to modify the respiratory protection program before granting 
provisional approval of your ventilation plan.
    Once MSHA grants provisional approval, we will verify the 
effectiveness of the revised dust control provisions of the ventilation 
plan. We will sample the environment of the DO and of those miners that 
your plan requires to wear approved PAPRs. If effectiveness of the plan 
is verified, it would become your interim ventilation plan.
    In order to continue using PAPRs for compliance purposes, you would 
be required to maintain the effectiveness of your engineering or 
environmental controls, as well as the effectiveness of your approved 
PAPR respiratory protection program. We believe that the effectiveness 
of a PAPR is dependent upon proper training and continued maintenance. 
Training and maintenance procedures are part of an effective 
respiratory protection program. The provision 30 CFR 72.710 requires 
all respirators used in an underground coal mine to be selected, 
fitted, used, and maintained in accordance with the provisions of the 
American National Standards Institutes ``Practices for Respirator 
Protection ANSI Z88.2-1969.'' These provisions include training miners 
in the use and maintenance of respirators and the limitations of the 
specific respirator worn. Necessary maintenance includes examining it 
for defects prior to use, charging the batteries properly, and 
appropriate replacement of parts including, but not limited to, the 
filter elements, visors, batteries, blowers, and face seals. 
Furthermore, all respiratory equipment used in an underground coal mine 
must be approved by the National Institutes for Occupational Safety and 
Health (NIOSH) under 42 CFR part 84.
    The use of PAPRs is not intended to be permanent. Their use as a 
supplemental control would be permitted only on an interim basis, until 
feasible engineering or environmental controls become available. You 
would have to implement any feasible engineering and environmental 
controls, as they become available.

Section 70.213  For my longwall operation, when will MSHA approve my 
interim ventilation plan incorporating a PAPR respiratory protection 
program?

    Approval of your interim mine ventilation plan would depend on the 
results of verification sampling and the operating conditions in effect 
for each sample. Paragraph (b) adds additional criteria or ``critical 
values'' for coal mine dust and quartz dust to those specified in 
Sec. 70.209. These additional critical values, listed in Table IV-2, 
would apply to the environments of workers required to wear PAPRs under 
the plan. The critical values given in Sec. 70.209 would continue to 
apply to DO samples. However, once an interim ventilation plan is 
approved, the position of the DO will change. Your plan would be 
approved if it reflects the dust control parameters in place during 
verification sampling and none of the verification samples exceed the 
corresponding critical values. No DO dust sample obtained during the 
verification process can exceed 2.0 mg/m\3\ (respirable coal mine dust) 
or 100 g/m\3\ (respirable quartz dust). Since we estimate a 
protection factor of two, no verification sample from the environment 
where workers are required to wear PAPRs could exceed 4.0 mg/m\3\ (coal 
mine dust) or 200 g/m\3\ (quartz dust).

  Table IV-2.--Critical Values for Verifying Plan Effectiveness in the
Environment of Workers Required To Wear PAPRs. The Result of Each Sample
  Used To Verify Plan Effectiveness for Such Work Environments Must Be
          Less Than or Equal to the Appropriate Critical Value
------------------------------------------------------------------------
                                                Critical
                                                value for     Critical
    Number of shifts meeting criteria for       coal mine     value for
            verification sampling             dust (g/m\3\)   (g/
                                                                m\3\)
------------------------------------------------------------------------
1...........................................          3.54           174
2...........................................          3.77           187
3...........................................          3.89           194
4 or more...................................          4.0            200
------------------------------------------------------------------------


[[Page 42148]]

Section 70.214  For my longwall operation, under what circumstances may 
I (the operator) continue to use PAPRs to supplement engineering or 
environmental controls?

    In order to continue use of PAPRs to supplement your engineering or 
environmental controls, you must comply at all times with the dust 
control provisions of your interim mine ventilation plan. This 
includes: (1) implementing and maintaining all feasible engineering or 
environmental controls on each shift; and (2) complying with all 
provisions of your approved PAPR respiratory protection program. In 
addition, to ensure the continued effectiveness of your approved dust 
control parameters, no DO sample taken by an MSHA inspector could 
exceed the applicable dust standard. Furthermore, no MSHA measurement 
for any miner working downwind of the DO could exceed twice the 
applicable dust standard.
    Finally, you would be required to continue to seek improvements and 
implement, when they became available, any feasible engineering or 
environmental controls. MSHA will follow-up on your efforts in this 
regard as part of its regular six-month review of your mine ventilation 
plan under Sec. 75.370.
    Respirator programs require continuous administrative attention to 
assure continued effectiveness. MSHA's District Manager would evaluate, 
at least quarterly, the effectiveness of all installed engineering or 
environmental controls, the effectiveness of your PAPR respiratory 
protection program, and your performance in complying with all other 
plan provisions.

Section 70.215  What if an MSHA DO sample exceeds the applicable dust 
standard, or an MSHA sample for a miner required to wear a PAPR exceeds 
twice the applicable dust standard.

    This proposed section would require you to review your dust control 
procedures and promptly take action which would prevent similar 
occurrences in the future. Also, you must review your approved PAPR 
respirator program to assure its continued effectiveness. Dust levels 
in excess of the applicable standard could result from a change in 
operating conditions, because of an abnormal condition or work 
practice, or due to production exceeding the VPL. If you determine that 
you cannot comply with the dust standard, you would need to amend your 
interim ventilation plan and submit it to the District Manager for 
review and approval.
    If you are cited under Sec. 75.371 for failure to comply with your 
approved interim plan, the District Manager may conduct an 
investigation to determine if you are complying with the dust control 
provisions of your approved interim ventilation plan. If the 
investigation discloses that you are not following your plan, MSHA may 
revoke approval of your plan.
    Finally, the District Manager may revoke your interim plan and 
withdraw permission to use PAPRs for compliance purposes if you have a 
record of noncompliance with your interim ventilation plan, or if MSHA 
samples indicate that miners are not adequately protected. If this 
occurs, your revised interim plan must include a VPL at which you can 
comply with the applicable standard.

Sections 70.216 Through 70.218

Use of Verifiable Administrative Controls

    These sections establish requirements for using verifiable 
administrative controls to supplement engineering or environmental 
controls.

Section 70.216  For my longwall operation, what must I (the operator) 
do in order to use verifiable administrative controls to supplement 
engineering or environmental controls?

    ``Verifiable administrative controls'' are work practices that 
reduce miners' daily exposure to respirable dust by altering the way in 
which work is performed such as rotating miners to areas having lower 
concentrations of respirable dust. To be considered verifiable 
administrative controls, it is necessary that the practices: (1) Can be 
reviewed to confirm proper implementation, (2) are clearly understood 
by miners, and (3) can be applied consistently over time. If you choose 
to use verifiable administrative controls for compliance purposes, 
paragraph (a) requires you to submit a revised ventilation plan to 
MSHA's District Manager within five days of receiving MSHA's written 
approval in accordance with Sec. 70.211. This plan must specify: (1) 
the feasible engineering or environmental controls to be used for 
reducing respirable dust concentrations to the lowest possible level; 
(2) the verifiable administrative controls to be implemented on the 
longwall MMU; and (3) the procedures to be employed for ensuring 
compliance with the verifiable administrative controls on every shift.
    Once MSHA grants provisional approval, we will verify the 
effectiveness of the revised dust control provisions of the ventilation 
plan. We will sample all miners working on the longwall face, including 
the DO (occupation code 044 or other occupation designated by the 
District Manager), to demonstrate effectiveness of the proposed dust 
control provisions. If effectiveness of the plan is verified, it would 
become your interim ventilation plan.
    The use of verifiable administrative controls is not intended to be 
permanent. Their use for compliance purposes would be permitted only on 
an interim basis, until feasible engineering or environmental controls 
become available. You would have to implement any feasible engineering 
and environmental controls, as they become available. You must make 
sure that you continue to comply with your approved administrative 
controls, and you must maintain the effectiveness of your engineering 
or environmental controls. Finally, you must implement any feasible 
engineering or environmental controls methods that become available, 
and that would prevent full shift dust concentrations from exceeding 
the applicable dust standard at any location at which miners normally 
work at the longwall face.

Section 70.217  For my longwall operation, when will MSHA approve my 
interim ventilation plan incorporating verifiable administrative 
controls?

    Approval of the dust control provisions of your interim ventilation 
plan depends on the results of your verification samples and on the 
actual operating conditions under which each sample was taken. None of 
the samples obtained during the verification process may exceed 2.0 mg/
m\3\ (coal mine dust) or 100 g/m\3\ (quartz dust). Under 
paragraph (b), MSHA's District Manager may approve the dust control 
provisions of your interim plan if (1) the plan reflects all dust 
controls, including administrative controls in effect during 
verification sampling and (2) none of the samples used to verify plan 
effectiveness exceed the appropriate critical values as specified and 
explained in Sec. 70.209.

Section 70.218  For my longwall operation with an approved interim 
ventilation plan, what if an MSHA sample exceeds the applicable dust 
standard?

    Under this section, you must immediately review your dust control 
procedures, including the effectiveness of your administrative 
controls, and take action to prevent similar occurrences in the future 
if any MSHA compliance sample exceeds the applicable dust

[[Page 42149]]

standard. Dust levels in excess of the applicable standard could result 
from a change in operating conditions, because of an abnormal condition 
or work practice, or due to production levels which exceed the VPL. If 
changes are made in your interim ventilation plan, you must submit them 
to the District Manager for review and approval.
    If you are cited under Sec. 75.371 for failure to comply with your 
approved plan, the District Manager may conduct an investigation to 
determine if you are complying with the dust control provisions of your 
approved interim ventilation plan. If the investigation discloses that 
you are not following your plan, approval of your plan may be revoked.
    Finally, the District Manager may revoke your interim plan and 
withdraw permission to use administrative controls for compliance 
purposes if you have a record of noncompliance with your interim 
ventilation plan, or if MSHA samples indicate that miners are not 
adequately protected. If this occurs, your revised interim plan must 
include a VPL at which you can comply with the applicable standard.
Actions Necessary When You Are in Violation of Respirable Dust 
Standards

Section 70.219  What must I (the operator) do if I am cited for 
exceeding the applicable dust standard?

    If you are cited for violating Sec. 70.100 or Sec. 70.101, you 
would be required to promptly review your dust control practices to 
determine the cause of the excessive dust concentration. You would also 
be required to take corrective action to prevent miners from being 
overexposed in the future by lowering the concentration of respirable 
dust to comply with the applicable dust standard. You would be required 
to take these actions within the abatement period fixed in a citation.
    After reviewing your dust control practices and taking corrective 
action, you would be required to incorporate changes reflecting these 
actions into your ventilation plan in accordance with 
Sec. 75.370(a)(2). If, in your opinion, the corrective actions taken do 
not warrant a change in your plan's dust control parameters, you would 
need to explain that in your response to the District Manager. This 
will enable the District Manager to determine if the ventilation plan 
should be changed and re-verified.
    Based on the dust parameters that were in use for the results of 
the compliance sample(s) dust concentrations measured by MSHA samples, 
and the information submitted by the operator regarding the type(s) of 
corrective action that were taken, MSHA may elect to sample the cited 
entity to determine the effectiveness of your abatement actions. If 
these samples indicate compliance with the applicable dust standard, 
you would be required to incorporate your corrective actions in your 
mine ventilation plan. At a minimum you would be required to 
incorporate in your plan the actual parameters that were in effect when 
MSHA sampled. If the MSHA samples indicate continued noncompliance, 
then MSHA may revoke approval of your ventilation plan.
Information To Be Posted on the Mine Bulletin Board

Section 70.220  What information must I (the operator) post on the mine 
bulletin board?

    This proposed section would provide ready access to current 
information relating to the plan verification process and to the 
respirable dust conditions in the mine. You would be required to post 
on the mine bulletin board the actual values of specific dust control 
parameters measured by MSHA on shifts used for plan verification and 
all sample results. For the same reason, the proposal would require 
that all written notifications received from the District Manager 
regarding any aspect of the plan verification process. You could remove 
the information from the mine bulletin board after the plan is approved 
by the District Manager.
    Also, you would also be required to post the results of MSHA 
compliance sampling on the bulletin board. These results must be posted 
for at least 31 days. These posting requirements are intended to 
promote miner awareness of the conditions under which the mine 
ventilation plan has been shown to be effective in controlling dust 
levels in their work environment. The goal is consistent with the 
statutory intent that miners play a role in preventing unhealthy 
conditions and practices where they work.
Status Change Reports

Section 70.221  What action must I (the operator) take if the 
operational status of my mine, MMU, or DA changes?

    In order to conduct verification and compliance sampling, it is 
essential that you provide current information to us concerning the 
production status of MMUs and DAs within those mines that are in 
producing status. Therefore, to reduce the chances of visiting a mine 
whose operating status prevents the MSHA inspector from sampling, you 
would continue to be required to report the change in operational 
status of the mine, MMU, or DA to the MSHA District Office or to any 
other MSHA office designated by the District Manager. You would also be 
required to report a change in operational status if it would affect 
the verification sampling requirements under this proposal. Status 
changes would be reported in writing within three working days after 
the status change occurred. The reporting of changes in operational 
status is not a new requirement and is contained in existing 
Sec. 70.220. MSHA is renumbering existing Sec. 70.220 as Sec. 70.221.

Changes to Part 75

Section 75.370  Mine Ventilation Plan; Submission and Approval

    This proposal would amend Sec. 75.370 by adding a new paragraph 
(h). Paragraph (h) would require that records of the amount of material 
produced each production shift by each MMU during the previous six-
month period be made available for inspection by authorized 
representatives of the Secretary and the miners' representative.
    These records are essential for the plan verification process. The 
records are needed to establish the verification production level (VPL) 
required under proposed Sec. 75.371(f) and to confirm that the 30-shift 
period on which the VPL is based represents typical production 
conditions for the MMU. Additionally, MSHA and the miners' 
representative need these records to monitor changes in production 
levels that may affect the plan's adequacy. Finally, because 
verification of a plan's effectiveness is conditioned on the VPL, these 
records are necessary to determine if the VPL used in approving a plan 
continues to reflect typical production levels at the mine.
    The production records for each MMU may be maintained in any form 
utilized by the operator to measure the total amount of material 
produced, so long as the method is the same as that used to establish 
the VPL required for plan verification. For example: number of loaded 
shuttle cars, feet of advance, raw tonnage, or number of longwall 
passes would each be an acceptable method of recording production--so 
long as the same method was consistently used.

Section 75.371  Mine Ventilation Plan; Contents

    The proposal would revise paragraphs (f) and (t). Existing 
paragraph (f) would be revised to require the ventilation plan to 
include any specific work practices used to minimize the dust

[[Page 42150]]

exposure of individual miners, information on the location of the roof 
bolter(s) during the mining cycle for each continuous miner section, 
and the cut sequence for each longwall mining section.
    Also, every ventilation plan would be required to include 
information on the length of each normal production shift and to 
specify the VPL as defined in Sec. 70.2. Although a VPL would be 
included in the ventilation plan, MSHA would not cite you for producing 
at levels exceeding the VPL. We would expect production on an MMU to 
exceed the VPL on about 33 percent of all production shifts. If the 
District Manager determines that your production exceeds the VPL on 
more than 33 percent of the production shifts over a six-month period, 
then this may trigger the plan verification process using a higher VPL.
    For interim plans involving the use of powered, air purifying 
respirators (PAPRs) or verifiable administrative controls, the plan 
must also include the information respectively required under 
Sec. 70.212(b) or Sec. 70.216(a). This additional information is 
necessary to fully assess the adequacy of mine ventilation plans.
    Since MSHA is proposing to revoke existing Secs. 70.207 and 70.208 
which require sampling by mine operators, existing paragraph (t) would 
be revised to remove the provision that mine operators identify in the 
mine ventilation plan the locations where samples for designated areas 
(DA) will be collected, including the specific location of each 
sampling requirement, and the reference to Sec. 70.208. However, to 
ensure that the mine atmosphere where miners are normally required to 
work or travel is continuously maintained in compliance, proposed 
paragraph (t) would continue to require mine operators to identify in 
the mine ventilation plan the location of each DA, defined in proposed 
Sec. 70.2(e), and the particular dust control measures that would be 
used at the dust generating sources for these locations. These 
locations would continue to be sampled by MSHA inspectors as discussed 
earlier (see Background Section) to determine compliance with the 
applicable standard and to assess the adequacy of the operator's dust 
control measures.

Part 90

    The proposed rule would revoke all operator sampling requirements 
associated with coal miners who have evidence of the development of 
pneumoconiosis under Part 90. MSHA is republishing the entire 
regulatory text of Part 90 as it would appear under the proposal for 
ease of review. Aside from a few technical clarifications which are 
described below, the only change to Part 90 would be to remove all 
references to operator sampling.

Section 90.1  Scope.

    The scope of part 90 would not change under the proposal. However, 
the phrase ``including respirable dust sampling for Part 90 miners'' 
would be removed from the end of the sentence which states that ``the 
rule also sets forth the operator's obligations.''

Section 90.2  Definitions.

    All definitions would remain unchanged under the proposal with the 
exception of those for ``concentration'' and ``mechanized mining unit'' 
which have been clarified as described below. The definition for 
``valid respirable dust sample'' would be removed because mine 
operators would no longer collect Part 90 samples under the proposal. 
No discussion has been included below if the definition would not 
change under the proposal. For ease of reference, subsection references 
have been added for each definition.
    Concentration is a measure of the amount of substance contained per 
unit volume of air.
    The existing definition would be modified so that ``concentration'' 
refers to an 8-hour Mining Research Establishment (MRE) equivalent 
measure of the amount of sampled material contained per unit volume of 
air. The proposed revision would include the constant factor of 1.38 
which the Secretary currently uses to convert concentration of 
respirable dust measured with approved sampling devices to an 
equivalent concentration as measured with an MRE instrument.
    The existing coal mine dust standards were developed from 8-hour 
shift exposure measurements. Therefore, if a sample is taken over a 
period other than eight hours, the concentration measurement must be 
adjusted to be equivalent to an eight-hour exposure. This is necessary 
in order to provide equal protection to miners working shifts greater 
than eight hours and would be accomplished by multiplying the sampler 
flow rate by 480 minutes, regardless of the length of time that the 
sample was actually collected.
    For this example, suppose a DO sample is collected over a 9-hour 
shift that includes one hour of travel time. Suppose that the amount of 
dust accumulated during travel is negligible, and the amount 
accumulated during production is 1.5 mg. If the concentration were not 
adjusted to an 8-hour equivalent, it would be diluted by the time spent 
traveling and calculated as 1.92 mg/m\3\. Under the proposed 
definition, the calculated concentration would be 2.16 mg/m\3\.
    The proposed definition does not change the daily limit on 
accumulated exposure intended by the existing exposure limit for coal 
mine dust. Since the current limit was based on an assumption that 
exposure occurs over an 8-hour shift, it corresponds to a daily 
cumulative exposure limit of 8  x  2.0 = 16 mg-hr/m\3\. The proposed 
definition of concentration would maintain this same MRE-equivalent 16 
mg-hr/m\3\ daily limit, regardless of the length of any shift worked.
    To continue the example, the exposure accumulated during a day is 
the same, whether from 8 hours at an average of 2.16 mg/m\3\ or from 9 
hours at an average of 1.92 mg/m\3\. In either case, the MRE-equivalent 
exposure accumulated for the day is 17.3 mg-hr/m\3\, which exceeds the 
intended daily limit of 16 mg-hr/m\3\. Under the proposed definition, 
this would be reflected by the fact that the calculated concentration 
exceeds 2.0 mg/m\3\. MSHA solicits comments on this method of adjusting 
concentrations to an 8-hour equivalent.
    Mechanized mining unit has been revised to refer to the proposed 
rule new Sec. 70.205. The definition also clarifies that each MMU is 
assigned a four digit identification number by MSHA. The MMU retains 
the identification number regardless of where the unit relocates within 
the mine. When two sets of mining equipment are provided in a series of 
working places and only one production crew is employed at any given 
time on either set of mining equipment, the two sets of equipment are 
to be identified as a single MMU. When two or more MMUs are 
simultaneously engaged in the production of material within the same 
working section, each such MMU is identified separately.

Section 90.100  Respirable dust standard.

    The Part 90 respirable dust standard would not change. Since MSHA 
would collect all Part 90 samples under the proposal, the sentence 
which provides that ``concentrations shall be measured with an approved 
sampling device and expressed in terms of an equivalent concentration 
determined in accordance with Sec. 90.206'' would be removed.

Section 90.101  Respirable dust standard when quartz is present.

    Because MSHA would collect all Part 90 samples, this section would 
be

[[Page 42151]]

changed by removing the sentence which provides that ``concentrations 
shall be measured with an approved sampling device and expressed in 
terms of an equivalent concentration determined in accordance with 
Sec. 90.206.''
    An example has been added to explain how a reduced standard is 
established when respirable dust associated with a part 90 miner 
contains quartz in the amount of 20%.

Section 90.102  Transfer; notice.

    This section would remain unchanged.

Section 90.103  Compensation.

    This section would remain unchanged.

Section 90.104  Waiver of rights; re-exercise of option.

    This section would remain unchanged.

Section 90.201  MSHA Respirable dust sample reports; Operator status 
change reporting requirement.

    Under the proposal, mine operators would no longer collect 
respirable dust samples under Subpart C of Part 90. Consequently, all 
of Subpart C, ``Sampling Procedures,'' including Secs. 90.201-209 would 
be removed. Existing Sec. 90.210 would be renumbered as Sec. 90.201. 
The requirements of this section would remain unchanged.

Section 90.202  Operator status change reports.

    Under the proposal, mine operators would no longer collect 
respirable dust samples under Subpart C of Part 90. Consequently, all 
of Subpart C, ``Sampling Procedures,'' including Secs. 90.201-209 would 
be removed. Existing Sec. 90.220 would be renumbered as Sec. 90.202. 
The requirements of this section would remain unchanged.

Section 90.300  Respirable dust control plan; filing requirements.

    There would be no change in the filing requirements for respirable 
dust control plans under the proposal.

Section 90.301  Respirable dust control plan; approval by District 
Manager; copy to part 90 miner.

    There would be no change in the approval process or notice 
requirements for respirable dust control plans under the proposal.

V. Health Effects

A. Introduction

    Since the 1800s, occupational respiratory disease associated with 
working in a coal mine has been commonly referred to as ``Black Lung.'' 
As coal is mined, respirable-sized dust is generated. Depending upon 
the mine location and its geologic features, silica may also be present 
in the mine atmosphere. Dust in air that is breathed by miners has the 
potential to be deposited in their lungs. Some of this dust may be 
retained. Coal mine dust remaining in the lungs of miners for prolonged 
periods of time has the potential to result in respiratory diseases, 
sometimes even after occupational exposure to respirable coal mine dust 
has stopped. There is a clear and direct relationship between miners' 
cumulative exposures (i.e., dose multiplied by the time exposed to the 
coal mine dust) to respirable coal mine dust and the severity of 
resulting respiratory conditions (as discussed more extensively, later 
in this section).
    Diseases resulting from long-term retention of coal mine dust in 
the lung include chronic coal workers' pneumoconiosis (simple CWP), 
progressive massive fibrosis (PMF), silicosis, and chronic obstructive 
pulmonary disease (COPD) (e.g., asthma, chronic bronchitis, emphysema). 
Historically, the medical term, ``pneumoconiosis,'' has included simple 
CWP and PMF and their sub-categories. Chronic, or simple, CWP is 
partitioned into three levels of severity, proceeding from lowest to 
highest: category 1, category 2, and category 3. Progressive Massive 
Fibrosis is similarly divided into three categories of increasing 
levels of severity: A, B and C.
    Miners with simple CWP have a substantially increased risk of 
developing PMF. In the advanced stages of pneumoconiosis (i.e., PMF), a 
significant loss of lung function may occur and respiratory symptoms 
(e.g., breathlessness, wheezing) may persist. Miners are at risk of 
increased morbidity and premature mortality due to simple CWP, PMF and 
various other respiratory diseases.
    Factors that are important in the development of simple CWP, PMF 
and COPD include the type of dust (e.g., coal and/or silica), dust 
concentration (to which the miner was exposed), number of years of 
exposure, age of the miner (often measured as age at time of medical 
examination), and rank of the coal (the higher the rank the greater the 
risk).
    In 1998, MSHA estimated that approximately 45,000 miners and 39,000 
miners were employed at underground and surface coal mines, 
respectively (Mattos, 1999). A small percentage of the mining involved 
anthracite coal, the highest rank coal, while most involved bituminous 
coal which is a medium rank coal.
    There are complementary data sources, described below, which 
provide estimates of the prevalence of occupational respiratory disease 
among coal miners. Together these data demonstrate the progress over 
the last thirty years in the reduction of occupational respiratory 
disease among coal miners, as well as the need for further action to 
reduce occupational lung disease among today's coal miners.
    Estimates of the prevalence of simple CWP and PMF among the 
underground coal miners are gathered from the x-ray program, through 
which operators are required to provide miners the opportunity to be 
evaluated periodically for the presence of occupational lung disease, 
mandated pursuant to Section 203(a) of the Mine Act (30 U.S.C. 843(a)). 
However, miners are not required to participate. From 1970 to 1995, the 
prevalence of simple CWP and PMF among miners participating in the 
mandated x-ray program has dropped from 11 percent to 3 percent (MSHA, 
Internal Chart, 1998).
    In accordance with 30 CFR part 50, those cases of occupational 
illnesses which both surface and underground coal mine operators learn 
of must be reported to MSHA. Under this requirement, mine operators 
reported 224 cases of pneumoconiosis (simple CWP and PMF, combined) in 
1998 (Mattos, 1999). Of these, 138 cases occurred among coal miners who 
worked underground, while the remaining 86 cases occurred among surface 
coal miners (Mattos, 1999). There were also 14 cases of silicosis, 
eight in underground mines, reported to MSHA in 1998 in accordance with 
30 CFR part 50 (Mattos, 1999). Since miners participate in both these 
programs at their own discretion, these data do not include the 
occupational health experience of all coal miners. The prevalence of 
occupational lung disease among participating miners may significantly 
differ from the prevalence among non-participants. Thus, the data from 
these programs may not be representative of the true magnitude of the 
prevalence of simple CWP and PMF among today's coal miners.
    In the 1990s, MSHA conducted a series of one-time medical 
surveillance programs, in various regions of the country, to develop a 
more accurate estimate of the prevalence of simple CWP and PMF. Through 
these special programs, MSHA tried to minimize obstacles which may 
prevent some miners from either participating in or reporting to 
operators the results of respiratory diagnostic procedures. Nine

[[Page 42152]]

geographical cohorts of miners, from around the country, were 
encouraged to participate in an independent x-ray program (MSHA, 
Internal Chart, 1999). These cohorts included eight active surface coal 
mining communities in the states of Pennsylvania, Kentucky and West 
Virginia, as well as the towns of Poteau, Oklahoma and Gillette, 
Wyoming. A ninth cohort included underground miners in Kentucky. The 
process was designed to encourage miner participation by providing for 
a greater degree of anonymity than may be available under the program 
provided by Section 203(a) of the Mine Act (30 U.S.C. 843(a)). Across 
the eight surface cohorts surveyed, the prevalence rate of simple CWP 
and PMF combined, among participants was 4.8%. The prevalence rate 
among the participating underground Kentucky miners was 9.2%.
    Also, as part of its ongoing effort to ``end black lung now and 
forever,'' beginning in October 1999, MSHA implemented a pilot program 
to provide miners at both surface and underground mines with 
confidential health screening. Referred to as the ``Miners' Choice 
Health Screening,'' the program addresses the key recommendations of 
the Secretary's Advisory Committee by (1) increasing participation 
toward the 85-percent level and (2) expanding the scope of the 
eligibility to include surface coal miners and surface coal mine 
independent contractors. The pilot program operates separately from the 
existing Coal Workers' X-ray Surveillance Program administered by 
NIOSH. Since the Miners' Choice Health Screenings' inception, over 
7,000 miners have been screened, with the participation rate in most 
areas exceeding 50 percent. With half of the x-rays taken during the 
first six months having been processed by NIOSH, preliminary results 
indicate a prevalence rate of approximately 2.25 percent.
    The National Institute for Occupational Safety and Health (NIOSH) 
and the Mine Safety and Health Administration (MSHA) are concerned 
about the prevalence of occupational lung disease among today's miners. 
Epidemiological studies from the U.S. and abroad have consistently 
shown that underground and surface coal miners are at risk of 
developing simple CWP, PMF, silicosis, and chronic obstructive 
pulmonary disease (NIOSH Criteria Document, 1995).

B. Hazard Identification

1. Agent: Coal
    Coal is a fossil fuel derived from partial degradation of 
vegetation. Through its combustion, energy is produced which makes coal 
a valuable global commodity. It has been estimated that over one-third 
of the world uses energy provided by coal (Manahan, 1994). 
Approximately 1,800 underground and surface coal mines are in operation 
in the United States annually producing slightly over a billion short 
tons of coal (Mattos, 1999).
    Coal may be classified on the basis of its type, grade, and rank. 
The type of coal is based upon the plant material (e.g., lignin, 
cellulose) from which it originated. The grade of coal refers to its 
chemical purity. Although coal is largely carbon, it may also contain 
other elements such as hydrogen, oxygen, nitrogen, and sulfur. ``Hard'' 
coal refers to coal with a higher carbon content (i.e., 90-95%) than 
``soft'' coal (i.e., 65-75%). Coal rank relates to geologic age, 
indexed by its fixed carbon content, down to 65%, and then by its 
heating value. Volatile matter varies inversely with the fixed carbon 
value. The most commonly described coal ranks include lignite (low 
rank), bituminous coal (medium rank), and anthracite (high rank) 
(Manahan, 1994).
2. Physical State: Coal Mine Dust
    Aerosols are a suspension of solid or liquid particles in air 
(Mercer, 1973); they may be dusts which are solid particles suspended 
in the air. Coal dust may be freshly generated or may be re-suspended 
from surfaces on which it is deposited in mines. As discussed below, 
coal mine dust may be inhaled by miners, depending upon the particle 
size.
    Coal mine dust is a heterogenous mixture, signifying that all coal 
particles do not have the same chemical composition. The particles are 
influenced by the type, grade, and rank of coal from which they were 
generated (Manahan, 1994). Irrespective of differences in coal 
characteristics, these dusts are water-insoluble, which is important 
biologically and physiologically. Unlike soluble dusts which may 
readily pass into the respiratory system and be cleared via the 
circulatory system, insoluble dusts may remain in the lungs for 
prolonged periods of time. Thus, a variety of cellular responses may 
result that could eventually lead to lung disease.
3. Biological Action: Respirable Coal Mine Dust
    The principal route of occupational exposure to respirable coal 
mine dust occurs via inhalation. As a miner breathes, coal mine dust 
enters the nose and/or mouth and may pass into the mid airways (e.g., 
bronchi, terminal bronchioles) and lower airways (e.g., respiratory 
bronchioles, alveolar ducts).
    Coal mine dust has a size distribution that is estimated to range 
between 1 and 100 micrometer (m) (1 m = 
10-\6\ m) (Silverman, et al., 1971). The size of coal 
particles is critical in determining the level of the respiratory tract 
at which deposition and retention occur (American Conference of 
Governmental Industrial Hygienists, 1999; American Industrial Hygiene 
Association, 1997).
    Particles that are above 10 m are largely filtered in the 
nasal passages, although some of these particles may reach the thoracic 
(or tracheal-bronchial) region of the lung (e.g., 6% of 20 m) 
(American Conference of Governmental Industrial Hygienists, 1999). 
Thus, there is evidence that ``oversized'' particles (i.e., >10 
m) can move beyond the nose, deeper into the respiratory 
tract. Particles below 10 m may easily move throughout the 
respiratory tract. As particle size decreases from 10 to 5 m, 
however, there is greater penetration into the mid and lower regions of 
the lung. Particles that are approximately 1-2 m are the most 
likely to be deposited in the lung (American Conference of Governmental 
Industrial Hygienists, 1999; Mercer, 1973). During mouth breathing, 
there may be a slight upward shift in the particle deposition curve 
such that 2-3 m-sized particles are the most likely to be 
deposited in the respiratory tract (Heyder, et al., 1986). Irrespective 
of nasal or mouth breathing, the potential respiratory tract 
penetration of particles whose size is approximately 10 m or 
less is important because particles in the respirable size range 
deposit in the deep lung where clearance is much slower.
    For the purposes of this rule, ``respirable dust'' is defined as 
dust collected with a sampling device approved by the Secretary of 
Labor and the Secretary of the Department of Health and Human Services 
(DHHS) in accordance with 30 CFR Part 74 (Coal Mine Dust Personal 
Sampler Units). In practice, the coal mine dust personal sampler unit 
has been used in the U.S. The particles collected with an approved 
sampler approximate that portion of the dust which may be deposited in 
the lung (West, 1990; 1992). It does not, however, indicate pulmonary 
retention (i.e., those

[[Page 42153]]

particles remaining in the lung). For those particles that are 
deposited in the lung, clearance mechanisms normally operate to assist 
in their removal. For example, within the thoracic (tracheal-bronchial) 
region of the lung, cilia (i.e., hairlike projections) line the airways 
and are covered by a thin layer of mucus. They assist in particle 
clearance by beating rhythmically to project particles toward the 
throat where they may be swallowed, coughed, sneezed, or expectorated. 
This rhythmic beating action is effective in removing particles fairly 
quickly (i.e., hours or days). Within the alveolar region of the lung, 
particles may be engulfed by pulmonary macrophages. These large 
``wandering cells'' may remove particles via the blood or lymphatics. 
This process, unlike the movement of the cilia is much slower (i.e., 
months or years). Thus, some particles, particularly those that are 
insoluble, may remain in the alveolar region for long periods of time, 
despite the fact that pulmonary clearance is not impaired. It is the 
pulmonary retention of coal mine dust which may be the impetus for 
respiratory disease.
    It is also important to note that silica may be present in the coal 
seam, within dirt bands in the coal seam, and in rock above and below 
coal seams. Of the silica found in coal mines, quartz is the form which 
is found. Thus, quartz may become airborne during coal removal 
operations (Manahan, 1994). Miners may inhale dust that is a mixture of 
quartz and coal. MSHA is concerned with the inhalation of quartz since 
it may be deposited in the lungs of miners and produce silicosis. This 
is a restrictive lung disease which is characterized by a stiffening of 
the lungs (West, 1990; 1992). Silicosis has been seen in coal miners 
(e.g., surface miners, drillers, roofbolters) (Balaan, et al., 1993). 
Silicosis may develop acutely (i.e., 6 months to 2 years) following 
intense exposure to high levels of respirable crystalline quartz. 
Silicosis has also been observed in coal miners following chronic 
exposure (i.e., 15 years or more), but may be accelerated (i.e., 7-10 
years) in some cases (Balaan, et al., 1993). Silicosis is irreversible 
and may lead to other illnesses and premature mortality. People with 
silicosis have increased risk of pulmonary tuberculosis infection and 
an increased risk of lung cancer (Althouse, et al., 1995; International 
Agency for Research on Cancer, 1997). MSHA's current standard of 2.0 
mg/m\3\ for respirable coal dust requires that quartz levels be 5% or 
lower. Otherwise, the 2.0 mg/m\3\ respirable coal dust exposure limit 
does not apply and must be adjusted downward for percent quartz. If 
coal dust contains more than 5% quartz, then the following formula is 
applied (30 CFR 70.101; 30 CFR 71.101):

Respirable dust standard (mg/m\3\) = [(10 mg/m\3\)/(%Quartz)]

The intent of this formula is to maintain miner exposures to quartz 
below 0.1 mg/m\3\ (100 g/m\3\).

C. Health-Related Effects of Respirable Coal Mine Dust

1. Description of Major Health Effects
    Consistently, epidemiological studies have demonstrated miners to 
be at risk of developing respiratory symptoms, a loss of lung function, 
and lung disease as a consequence of occupational exposure to 
respirable coal mine dust. As noted previously, risk factors include 
type(s) of dust, dust concentration, duration of exposure, age of the 
miner (often measured as age at time of medical examination), and coal 
rank.
    a. Simple Coal Workers' Pneumoconiosis (Simple CWP) and Progressive 
Massive Fibrosis (PMF). In earlier stages of pneumoconiosis the term, 
``simple coal workers' pneumoconiosis'' (simple CWP), has been used, 
while in more advanced stages, the terms ``complicated CWP'' and PMF 
have been used interchangeably. Simple CWP and PMF involve the lung 
parenchyma and are produced by deposition and retention of respirable 
coal dust in the lung.
    To determine if a miner has simple CWP or PMF, chest x-rays are 
taken and classified by a certified radiologist or reader. Opacities 
are identified on chest films and then classified using a scale of 0-3 
(e.g., simple CWP category 1), where higher category values indicate 
increasing concentration of opacities. In some instances, two category 
values may be given. For example, simple CWP category \2/3\ signifies 
that the reader decided the film was category 2, but suspected that it 
might have been category 3. The International Labour Office (ILO) has 
provided a full description of the criteria for these classifications 
(ILO, 1980).
    Simple CWP can be associated with a loss of lung function and with 
premature mortality (Morgan, et al., 1974; Jacobsen, 1976; Cochrane, et 
al., 1979; Parkes, 1982). MSHA recognizes that simple CWP increases the 
risk of developing PMF substantially (Cochrane, 1962; Jacobsen, et al., 
1971; McLintock, et al., 1971; Balaan, et al., 1993).
    Progressive massive fibrosis (PMF) is associated with decreased 
lung function and increased premature mortality (Rasmussen, et al., 
1968; Atuhaire, et al., 1985; Miller and Jacobsen, 1985; Attfield and 
Wagner, 1992). Progressive massive fibrosis is also associated with 
increases in respiratory symptoms such as chest tightness, cough, and 
shortness of breath. Miners with PMF also have an increased risk of 
acquiring infections and pulmonary tuberculosis (Petsonk and Attfield, 
1994; Yi and Zhang, 1996). Finally, miners with PMF have an increased 
risk of right-side heart failure (i.e., cor pulmonale) (Cotes and 
Steel, 1987).
    b. Other Health Effects. During a medical examination, a miner may 
be questioned by his physician about symptoms such as cough, phlegm 
production, chest tightness, shortness of breath, and wheezing. 
Occupational physicians may also conduct pulmonary function tests using 
spirometry or plethysmography. Pulmonary performance may be assessed 
via repeated measurements of lung volumes and capacities, such as the 
forced expiratory volume in one second (FEV1), vital 
capacity (VC), forced vital capacity (FVC), residual volume (RV), and 
total lung capacity (TLC) (West, 1990; 1992). Changes in lung volumes 
and capacities may indicate a loss of the integrity of the lung (i.e., 
respiratory system). More importantly, they can provide information for 
diagnosis of diseases affecting the airways and/or elasticity of the 
lung (i.e., obstructive vs. restrictive lung disease)(West, 1990; 
1992).
    The term, chronic obstructive pulmonary disease (COPD), refers to 
three disease processes that are often difficult to properly diagnose 
and differentiate: chronic bronchitis, emphysema, and asthma (Coggon 
and Taylor, 1998; Garshick, et al., 1996; West, 1990; 1992). As 
indicated by several studies, the exposure of miners to respirable coal 
mine dust place them at increased risk of developing COPD. Furthermore, 
COPD may occur in miners with or without the presence of simple CWP or 
PMF.
    Chronic Obstructive Pulmonary Disease (COPD) is characterized by 
airflow limitations, and thus there is a loss of pulmonary function. As 
in simple CWP or PMF, a miner with COPD may have a variety of 
respiratory symptoms (e.g., shortness of breath, cough, sputum 
production, and wheezing) and may be at increased risk of acquiring 
infections. Chronic Obstructive Pulmonary Disease is associated with 
increased premature mortality (Hansen, et al., 1999; Meijers, et al., 
1997).
    Briefly, in chronic bronchitis and in asthma, there is excess 
mucous

[[Page 42154]]

secretion in the mid-lower airways (West, 1990; 1992). In contrast, 
emphysema is characterized by dilatation (enlargement) of alveoli that 
are distal to the terminal bronchioles, which leads to poor gas 
exchange (i.e., poor transfer of oxygen and carbon dioxide). 
Additionally, there is a breakdown of the interstitium between the 
alveoli. These pathological changes may be confirmed upon autopsy. With 
asthma, the airflow limitations may be partially or completely 
reversible, while they are only partially reversible with chronic 
bronchitis and emphysema.
    The Mine Safety and Health Administration (MSHA) and the NIOSH 
recognize that respiratory symptoms, loss of lung function, and COPD 
may impair the ability of a miner to perform his job and may diminish 
his quality of life. Additionally, miners having such health effects 
are at increased risk of morbidity (e.g., from cardio-pulmonary 
disease, infections) and premature mortality.
2. Toxicological Literature
    To better understand the human health effects of exposure to 
respirable coal mine dust and to more fully characterize the associated 
risks, it is important to consider data that have been obtained in 
animal based toxicological studies. To date, sub-acute studies (a study 
with a duration of 30 days, or less, in which multiple exposures of the 
same agent are given) and chronic studies (a study with a duration of 
more than 3-months, in which multiple exposures of same agent are 
given) attempted to mimic miners' exposures. Inhalation was generally 
the route of exposure, although several studies have also employed 
instillation techniques (i.e., a method which places a known quantity 
of dust into the trachea or bronchi).
    Most recent toxicological studies have been short-term studies, 
largely focusing on ``lung overload'' (Sipes, 1996; Oberdorster, 1995; 
Morrow, 1988, 1992; Witschi, 1990), species-dependent lung responses 
(Nikula, et al., 1997a,b; Mauderly, 1996; Lewis, et al., 1989; Moorman, 
et al., 1975), and particle size-dependent lung inflammation (Soutar, 
et al., 1997). The data have shown that pulmonary clearance of 
particles may become impaired, potentially leading to inflammatory and 
other cellular responses in the lung. Although overloading has not been 
demonstrated in humans, the finding of reduced lung clearance among 
retired U.S. coal miners (Freedman and Robinson, 1988) is consistent 
with this possibility.
    The data from Moorman, et al. (1975), Lewis, et al. (1989), and 
Nikula, et al. (1997a,b) are noteworthy for several reasons. First, 
these groups of investigators conducted chronic inhalation toxicity 
studies (i.e., chronic bioassays). This is important since miners' 
exposures also occur via inhalation, and over a working lifetime. 
Secondly, the investigators used an exposure concentration of 2.0 mg/
m\3\ in their bioassays. As noted above, this is the current MSHA 
standard for respirable coal mine dust. Thirdly, the exposures involved 
nonhuman primates, whose responses are thought to closely mimic those 
of man. Some of the key findings of these studies included: deposition 
of coal dust in the animals' lungs, retention of coal dust in alveolar 
tissue, altered lung defense mechanisms, reduced pulmonary airflows, 
and hyperinflation of the lungs. One of the shortcomings of these 
studies is that complete dose-response relationships were not 
developed. However, at higher exposure concentrations, greater effects 
may be expected which is a basic tenet of toxicology. Thus, at exposure 
concentrations above 2.0 mg/m\3\, MSHA and NIOSH believe that more 
severe obstructive lung disease may occur.
3. Epidemiological Literature
    Epidemiology studies have consistently demonstrated the serious 
health effects of exposure to high levels of respirable coal mine dust 
(i.e., above 2.0 mg/m\3\) over a working lifetime.
    Table V-1 lists epidemiology studies since 1986 whose results will 
be discussed on the basis of the type of observed health effect. 
Studies completed even earlier including the early work of Cochrane 
(1962), McLintock, et al. (1971), and Jacobsen, et al. (1971) 
demonstrated the adverse health effects (e.g., simple CWP, PMF) of 
respirable coal mine dust in British coal miners.
    Both early and recent studies have shown that the lung is the major 
target organ (i.e., organ in which toxic effects occur) when exposure 
to respirable coal mine dust occurs. As seen in Table V-1, numerous 
studies of miners have been conducted. Recent U.S. studies were 
conducted using data from one or more of the first four rounds of the 
National Study of Coal Workers' Pneumoconiosis (NSCWP), and have 
provided extensive data on miners' health. Many of these studies 
demonstrated that miners are at increased risk of multiple, concurrent 
respiratory ailments (Attfield and Seixas, 1995; Kuempel, et al., 1997; 
Meijers, et al., 1997; Seixas, et al., 1992).

    Table V-1.--Respirable Coal Mine Dust Epidemiological Studies, by
                 Reported Outcomes From 1986 to Present
------------------------------------------------------------------------
               Studies                         Reported outcomes
------------------------------------------------------------------------
Meijers, et al.,1997................  PMF, CWP, COPD, LLF
Maclaren, et al.,1989...............  PMF, CWP, LLF, RS
Kuempel*, et al.,1995...............  PMF, CWP, COPD
Bourgkard et al.,1998...............  PMF, CWP, LLF
Kuempel*, et al.,1997
Love, et al.,1997
Love, et al.,1992
Attfield and Morring*,1992b.........  PMF, CWP
Attfield and Seixas*, 1995
Hodous and Attfield*, 1990
Hurley and Jacobsen, 1986
Hurley and Maclaren, 1987
Hurley, et al., 1987
Starzynski, et al., 1996
Yi and Zhang, 1996
Wang, et al.,1997...................  CWP, LLF
Goodwin and Attfield*, 1998.........  CWP
Morfeld, et al., 1997

[[Page 42155]]

 
Marine, et al.,1988.................  COPD, LLF, RS
Seixas*, et al., 1993
Soutar and Hurley, 1986
Carta, et al.,1996..................  LLF, RS
Henneberger and Attfield*, 1997
Henneberger and Attfield*, 1996
Seixas*, et al., 1992
Attfield and Hodous*, 1992..........  LLF
Lewis, et al., 1996
------------------------------------------------------------------------
COPD: Chronic obstructive pulmonary disease
CWP: Simple coal workers' pneumoconiosis
LLF: Loss of lung function
PMF: Progressive massive fibrosis
RS: Respiratory symptoms
*: Studies of U.S. Miners Who Participated in the National Study of Coal
  Workers' Pneumoconiosis (NSCWP)

    a. Simple Coal Workers' Pneumoconiosis (Simple CWP) and Progressive 
Massive Fibrosis (PMF). Studies following Cochrane (1962) and McLintock 
et al. (1971) have confirmed that the risk of PMF increases with 
increasing category of simple CWP (Hurley and Jacobsen, 1986; Hurley, 
et al., 1987; Hurley and Maclaren, 1988; Hodous and Attfield, 1990). 
However, the risk of PMF was greater than previously predicted among 
miners with simple CWP category 1 or without simple CWP (i.e., category 
0) (Hurley, et al., 1987). The risk of PMF increased with increasing 
cumulative exposure, regardless of the initial category of simple CWP 
(Hurley, et al., 1987), indicating that reducing dust exposures is a 
more effective means of reducing the risk of PMF than reliance on 
detection of simple CWP.
    Attfield and Seixas (1995) have demonstrated a relationship between 
cumulative exposure to respirable coal mine dust and predicted 
prevalence of pneumoconiosis (i.e., simple CWP, PMF). They studied a 
group of approximately 3,200 men who worked in underground bituminous 
coal mines. The U.S. miners and ex-miners had participated in Round 1 
(1970-1972) or Round 2 (1972-1975) of the NSCWP and were examined again 
between 1985 and 1988. Chest x-rays were read to determine the number 
of cases of simple CWP and PMF. Dust exposure estimates were generated 
from measurements of dust concentrations as well as from work history. 
A logistic (or logit) regression model was used to estimate prevalence 
of simple CWP and PMF. In this statistical analysis, proportions are 
transformed to natural logarithmic values, i.e., y = ln [p/(1-p), 
before a linear model is fit to the data (Armitage, 1977). The logistic 
model assumes that the data have a binomial distribution (e.g., 
presence or absence of PMF) for a given set of covariate values (e.g., 
age, coal rank, dust exposure, pack-years of smoking). Using logistic 
modeling, relationships were developed between cumulative dust exposure 
and prevalence of simple CWP (category 1+, category 2+) and PMF. These 
relationships were the key strengths of the Attfield and Seixas study 
and serve as the basis for the Quantitative Risk Assessment of this 
rule.
    The recent paper of Kuempel, et al. (1997) has provided a detailed 
discussion and quantitative presentation of excess risks associated 
with respirable coal dust exposures. Their study was based upon results 
from previous studies of some 9,000 underground coal miners who 
participated in the NSCWP (Attfield and Morring, 1992b; Attfield and 
Seixas, 1995). Kuempel, et al. estimated excess (exposure-attributable) 
prevalence of simple CWP and PMF (i.e., number of cases of disease 
present in a population at a specified time, divided by the number of 
persons in the population at that specified time). Point estimates of 
excess risk of PMF ranged from 1/1000 to 167/1000 among miners exposed 
at the current MSHA standard for respirable coal mine dust. These 
estimates were based upon dust exposure that occurred over a miner's 
working lifetime (e.g., 8 hours per day, 5 days a week, 50 weeks per 
year, over a period of 45 years). Actual occupational lifetime exposure 
may be more, due to extended work shifts and work weeks. The point 
estimates of PMF presented by Kuempel, et al. (1997) were related to 
coal rank, where higher estimates (e.g., 167/1000) were obtained for 
high-rank coal (anthracite coal) and somewhat lower estimates were 
obtained for medium/low rank bituminous coal (e.g., 21/1000). Within 
each coal rank, the estimates of simple CWP cases were at least twice 
as high as those for PMF (e.g., 167/1000 PMF vs. 380/1000 simple 
CWP1).
    The data of Attfield and Seixas (1995) and Kuempel, et al. (1995; 
1997) were consistent with previous data of Attfield and Morring 
(1992b) who reported relationships between estimated dust exposure and 
predicted prevalence of simple CWP or PMF. They also noted that 
exposure-response relationships were steeper for higher ranks of coal 
such as anthracite, and concluded that the risks for anthracite miners 
appeared to be greater than for miners exposed to lower rank coal dust. 
Attfield and Morring (1992b) used similar methods as described above 
(i.e., logistic modeling), but included miners from Round 1 of the 
NSCWP (1969-1971); thus representing an earlier time point in the NSCWP 
when the respirable coal mine dust concentrations were much higher than 
they are today.
    Recently, Goodwin and Attfield (1998) reported that there were 
concerns regarding methodological inconsistencies across surveys given 
during the four rounds of the NSCWP. In particular, they noted the 
discordance in classification of simple CWP and PMF among readers of 
chest films. Despite potential discordance, Goodwin and Attfield (1998) 
have confirmed previous findings of a decline in simple CWP prevalence 
from 1969 to 1988. Yet, these analyses also demonstrated that simple 
CWP has not been eliminated. The Round 4 prevalence rates were 3.9 
percent for simple CWP category 1 and higher, and 0.9 percent for 
category 2 and higher. This illustrates the need for continued efforts 
to reduce dust exposures.
    Given the current system for monitoring exposures and identifying 
overexposures in the U.S., miners are at

[[Page 42156]]

increased risk of developing simple CWP and PMF from a working lifetime 
exposure to respirable coal mine dust (Kuempel, et al. 1997, 1995; 
Attfield and Seixas, 1995; Goodwin and Attfield, 1998; Attfield and 
Morring, 1992b). Whenever overexposures (i.e., excursions above the 
applicable standard) occur, the long-term mean exposure of miners may 
be increased, thereby causing an upward shift on the exposure-response 
curve. Such a shift then places these overexposed coal miners at 
increased risk of developing and dying prematurely from simple CWP and 
PMF.
    The Attfield and Seixas epidemiological study (1995) is the most 
appropriate to use in estimating the benefit of reduction of 
overexposures. The authors applied scientific rigor to the collection, 
categorization, and analyses of the radiographic evidence for the group 
of 3,194 underground bituminous coal miners who participated in Round 
4, 1985-1988, of the National Study of Coal Workers' Pneumoconiosis 
(NSCWP); this study population excludes 86 miners for whom there was 
missing exposure data or unreadable x-rays. Radiologic evidence was 
carefully collected and analyzed by multiple independent, NIOSH 
certified B readers to identify stages of simple CWP and PMF. In the 
targeted population of 5,557 miners, the participating miners (3,280) 
were similar to the non-participants (2,277) with regard to age at the 
first medical examination and prevalence of simple CWP category 1 or 
greater. The non-participants had worked slightly longer, yet had lower 
prevalence of simple CWP category 2 or greater, than the participants. 
This study describes the differences among current miners and ex-miners 
(health-related or job-related) in the relationships between the 
estimated cumulative exposure to respirable coal mine dust and 
prevalence of simple CWP category 1 or greater. Such data and 
relationships were not available in other U.S. studies and non-U.S. 
studies.
    A potential limitation in the U.S. studies is the possible bias in 
the exposure data, which has been the subject of several studies (Boden 
and Gold, 1984; Seixas et al., 1991; Attfield and Hearl, 1996). An 
advantage of the Attfield and Seixas 1995 study (and the earlier 
studies based on the same data set) is that the larger mines included 
in these epidemiological studies were shown to have exposure data with 
relatively small bias (Attfield and Hearl, 1996). Another limitation in 
exposure data used in the U.S. studies is that the airborne dust 
concentrations used to estimate individual miners' cumulative exposures 
to respirable coal mine dust were based on average concentrations 
within job category (these average values were combined with data of 
each individual miner's duration employed in a given job). The earlier 
U.S. exposure-response studies of miners participating in the first 
medical survey of the NSCWP (Attfield and Morring, 1992b; Attfield and 
Hodous, 1992; Kuempel, et al., 1995) relied primarily on exposure 
measurements from a dust sampling survey during 1968-1969 to estimate 
miners' exposures before 1970 (Attfield and Morring, 1992a). An 
advantage of the Attfield and Seixas 1995 study is that, in addition to 
the pre-1970 exposure estimates, more detailed exposure data were 
available to estimate miners' exposures from 1970 to 1987, during which 
the mean airborne concentrations were stratified by mine, job, and year 
(Seixas, et al., 1991).
    The most complete exposure data available are those for coal miners 
in the United Kingdom (Hurley, et al., 1987; Hurley and Maclaren, 1987; 
Soutar and Hurley, 1986; Marine, et al., 1988; Maclaren, et al., 1989). 
These studies include medical examinations and individual estimates of 
exposure for more than 50,000 miners for up to 30 years. The U.S. 
studies are consistent with these U.K. studies in demonstrating the 
risks of developing occupational respiratory diseases from exposure to 
respirable coal mine dust. These risks increase with increasing 
exposure concentration and duration, and with exposure to dust of 
higher ranked coal. The quantitative assessment of risk and associated 
benefits were based on the Attfield and Seixas (1995) study because, in 
addition to the advantages described above, it best represents the 
recent conditions experienced by miners in the U.S. This quantitative 
assessment follows in Section VI. The international studies provide an 
important basis for comparison with the U.S. findings, and several of 
the recent international studies are described in detail here.
    Bourgkard, et al. (1998) conducted a 4-year study of a group of 
French coal miners who were employed in underground and surface mines. 
The investigators examined the prognostic role of cumulative dust 
exposure, smoking patterns, respiratory symptoms, lung CT scans, and 
lung function indices for chest x-ray worsening and evolution to simple 
CWP and PMF. Bourgkard, et al. (1998), through selection of a younger 
worker population (i.e., 35-48 years old at start of study), attempted 
to focus on the early stages of simple CWP. In essence, they hoped to 
identify those miners who needed to be relocated to less dusty 
workplaces or who needed to be clinically monitored. Bourgkard, et al. 
(1998) concluded that there was an association between cumulative dust 
exposure and what was termed chest x-ray ``worsening'' (i.e., increase 
in reader-designated category signifying progression of simple CWP). 
Their conclusion, however, was based on pooling of the data (i.e., 
three combined groups of miners) who had different cumulative exposures 
(i.e., 20, 66 and 85 mg-yr/m\3\).
    Love, et al. (1997, 1992) reported on occupational exposures and 
the health of British opencast (i.e., surface or strip) coal miners. 
They studied a group of approximately 1,200 miners who were employed at 
sites in England, Scotland, and Wales. The mean age of the men was 41; 
many had worked in the mining industry since the 1970s. To determine 
dust exposure levels, full shift personal samples were collected. Most 
were respirable dust samples which were collected using Casella 
cyclones according to the procedures described by the British Health 
and Safety Executive (HSE). Thus exposure determinations would be 
comparable to exposure determinations obtained in U.S. surface coal 
mines since both measure respirable dust according to the BMRC 
criteria.
    These investigators found a doubling in the relative risk of 
developing profusion of simple CWP category 0/1 for every 10 years of 
work in the dustiest jobs in surface mines. These respirable coal dust 
exposures were under 1 mg/m\3\. Love, et al. (1992, 1997), like other 
investigators, emphasized the need for monitoring and controlling 
exposures to respirable coal mine dust, particularly in high risk 
operations (e.g., drillers, drivers of bulldozers).
    Meijers, et al. (1997) studied Dutch coal miners who were examined 
between 1952 and 1963, and who were followed until the end of 1991. 
They reported an increased risk of mortality from simple CWP and PMF 
among miners who had generally worked underground for 20 or more years. 
Their conclusions were based upon dramatic increases in standardized 
mortality ratios (SMRs). There were several limitations in this study, 
however.
    Morfeld, et al. (1997) published a recent paper that investigated 
the risk of developing simple CWP in German miners and addressed the 
occupational exposure limit for respirable coal dust in Germany. Their 
study included approximately 5,800 miners who worked underground from 
the late

[[Page 42157]]

1970s to mid-1980s. Morfeld, et al. observed increases in relative 
risks (RRs) of developing early x-ray changes, category 0/1, that were 
exposure-dependent. Relative risks (RRs) increased with higher dust 
concentrations.
    Starzynski, et al. (1996) conducted a mortality study on a group of 
11,224 Polish males diagnosed with silicosis, simple CWP, or PMF 
between 1970 and 1985. This cohort was subdivided by occupation into 
four subcohorts: coal miners (63%); employees of underground work 
enterprises (8%) (i.e., drift cutting and shaft construction jobs); 
metallurgical industry and iron, and nonferrous foundry workers (16%); 
and refractory materials, china, ceramics and quarry workers. The 
investigators found that coal miners had a slight, statistically 
significant excess overall mortality (i.e., all causes) as indicated by 
a Standardized Mortality Ratio (SMR) of 105 (with a 95% Confidence 
Interval (C.I.) of 100-110). Also, excess of deaths from diseases of 
the respiratory system among coal miners was nearly four times that of 
the referent population (SMR of 383 with a 95% C.I. of 345-424). The 
study of Starzynski, et al. (1996) agrees with others that there is 
premature mortality among coal miners from simple CWP and PMF. 
Unfortunately, there is little or no information presented on miner 
work history, exposure assessment (e.g., respirable coal mine dust, 
silica), and mine environment (e.g., coal rank(s), underground vs. 
surface mining).
    Yi and Zhang (1996) conducted a study to measure the progression 
from simple CWP to PMF or death among a cohort of 2,738 miners with 
simple CWP who were employed at the Huai-Bei coal mine in China. 
Relative risks (i.e., RRs) were calculated for progression from simple 
CWP category 1 to simple CWP category 3 and for progression from simple 
CWP category 3 to death. Their results demonstrated that miners with 
simple CWP category 1 are at risk of developing simple CWP category 2 
and simple CWP category 3 (e.g., RRs of 1.101 and 2.360, respectively). 
They also found that miners with PMF had a decreased life expectancy. 
Other risk factors for development of PMF included long-term work 
underground, and drilling. This study was limited by a lack of exposure 
assessment, estimation of miner smoking histories, and use of a 
radiological classification system that differs from that of the ILO.
    Hurley and Maclaren (1987) studied British coal miners who were 
examined between 1953 and 1978, over 5-year intervals. They have shown 
that exposure to respirable coal dust increases the risks of developing 
simple CWP and of progressing to PMF. As seen in their data analysis, 
these responses were dependent upon dust concentration and coal rank. 
That is, greater responses were seen at higher dust concentrations and 
with higher rank coal (i.e., increasing per cent carbon. The 
investigators also noted that estimated risks were unaffected by 
changes in the proportion of miners with simple CWP who transferred 
jobs. The authors concluded that ``limiting exposure to respirable coal 
dust is the only reliable way of limiting the risks of radiological 
changes to miners.''
    b. Other Health Effects. As noted in Table V-1, there were 16 
studies in which the loss of lung function (LLF) was examined in coal 
miners. Six of these studies also included an evaluation of respiratory 
symptoms (RS) in the miners. There were five studies describing chronic 
obstructive pulmonary disease (COPD) in miners.
    Henneberger and Attfield (1997; 1996), Kuempel, et al. (1997), 
Seixas, et al. (1993), Attfield and Hodous (1992), and Seixas, et al. 
(1992) evaluated data from pulmonary function tests and standardized 
questionnaires to miners in the NSCWP. A common finding in their 
studies was an increase in respiratory symptoms such as cough, 
shortness of breath, and wheezing. The symptoms were dependent upon the 
dust concentration to which the miners had been exposed, with more 
pronounced symptoms occurring after long-term exposures to higher 
exposure levels. These studies also demonstrated that a loss of lung 
function occurred among miners.
    Attfield and Hodous (1992) studied U.S. miners who had spent 18 
years underground (on average) and who participated in Round 1 (1969-
1971) of the NSCWP. They observed that greater reductions in pulmonary 
function were associated with exposure to higher ranks of coal (i.e., 
anthracite vs. bituminous vs. lignite). Using linear regression models, 
Kuempel et al., (1997) predicted the excess (exposure attributable) 
prevalence of lung function decrements among miners with cumulative 
exposures to respirable coal mine dust of 2 mg/m\3\ for 45 years (i.e., 
90 mg-yr/m\3\). The excess prevalence estimated were 315 and 139 cases 
per thousand for forced expiratory volume in one second 
(FEV1) of 80% and 65% of predicted normal values, 
respectively, among never-smoking miners (a sub-group of 977 NSCWP 
participants studied in Seixas et al., 1993). Such reductions in 
(FEV1 are clinically significant; (FEV1 80% (of 
predicted normal values) is a measure that is used to determine 
ventilatory defects (American Thoracic Society, 1991). Three recent 
studies found impaired (FEV1 to be a predictor of increased 
pre-mature mortality (Weiss, et al., 1995; Meijers, et al., 1997; 
Hansen et al., 1999).
    Seixas, et al. (1993) conducted an analyses of 977 underground coal 
miners who began working in or after 1970 and were participants of both 
NSCWP Round 2 (1972-1975) and Round 4 (1985-1988). They found a rapid 
loss of lung function in miners and further declines in lung function 
with continuing exposure to coal mine dust. Collectively these studies 
have shown that the prevalence of decreased lung function was 
proportional to cumulative exposure. That is, with exposure to higher 
coal dust levels over a working lifetime, there were more miners who 
experienced a loss of lung function. Also, the types of respiratory 
symptoms and patterns of pulmonary function decrements observed by both 
Attfield and Hodous (1992) Seixas, et al. (1992;1993) are 
characteristic of COPD.
    The U.S. findings on respiratory symptoms and loss of lung function 
in miners have agreed with those of previous British studies by Marine, 
et al. (1988) and Soutar and Hurley (1986). Marine, et al. (1988) 
analyzed data from British coal miners and focused their attention on 
respiratory conditions other than simple CWP and PMF. In particular, 
they examined the Forced Expiratory Volume in one second 
(FEV1) among smoking and nonsmoking miners and, on the basis 
of reported respiratory symptoms, identified those miners with 
bronchitis. Using these data, logistic regression models were used to 
estimate the prevalence of chronic bronchitis and loss of lung 
function. Marine, et al. concluded that both exposure to respirable 
coal mine dust and smoking independently cause decrements in lung 
function; their contributions to COPD appeared to be additive in coal 
miners.
    Soutar and Hurley (1986) examined the relationship between dust 
exposure and lung function in British coal miners and ex-miners. The 
men who were studied were employed in coal mines in the 1950s and were 
followed up and examined 22 years later. These miners and ex-miners 
were categorized as smokers, ex-smokers, or nonsmokers. The Forced 
Expiratory Volume in one second (FEV1), the Forced Vital 
Capacity (FVC), and the (FEV1/FVC) ratios decreased in all 
study groups and these reductions in lung function were inversely 
proportional to dust exposure. Thus, Soutar and Hurley concluded that 
exposure to respirable coal mine dust can cause severe respiratory

[[Page 42158]]

impairment, even without the presence of simple CWP or PMF. They 
speculated that the pathology of coal dust-induced lung disease differs 
from that induced by smoking.
    Recent studies from China (Wang, et al., 1997) and the European 
community (Bourgkard, et al., 1998; Carta, et al., 1996; Lewis, S., et 
al., 1996) have also supported the British and U.S. findings which 
demonstrated the correlation between occupational exposure to coal dust 
and respiratory symptoms and loss of lung function in miners.
    Wang, et al. (1997) examined lung function in underground coal 
miners and other workers from several other factories in Chongqing, 
China. For their study, information was obtained on exposure duration, 
results of radiographic tests, and smoking history. Pulmonary function 
tests were performed, providing the Forced Expiratory Volume in one 
second (FEV1), the Forced Vital Capacity (FVC), and 
(FEV1/FVC) data. Additionally, the diffusing capacity for 
carbon monoxide (DLCO) was measured. This is an indicator of 
diffusion impairment at the ``blood-gas barrier'' which may occur, for 
example, when this barrier becomes thickened (West, 1990; 1992). Wang, 
et al. (1997) found that there was impairment of pulmonary function 
among the coal miners and they had evidence of obstructive disease. 
Like other studies, such effects were observed among coal miners even 
in the absence of simple CWP. Pulmonary function was further decreased 
when simple CWP was present. This study did not provide exposure 
measurements and there was no consideration of exposure-response 
relationships. Also, silica exposures and their potential effects were 
not examined in the underground coal miners.
    As noted above, Bourgkard, et al. (1998) was interested in the 
earlier stages of simple CWP (i.e., Categories 0/1 and 1/0) and the 
prognostic role of cumulative dust exposure, smoking patterns, 
respiratory symptoms, lung CT scans, and lung function indices for 
chest x-ray worsening and evolution to simple CWP category 1/1 or 
higher. Over a 4-year period, they studied French coal miners who were 
employed in underground and surface mines. Bourgkard, et al. (1998) 
found that, at the first medical examination, the ratio of the Forced 
Expiratory Volume in one second (FEV1) to the Forced Vital 
Capacity (FVC) (i.e., (FEV1/FVC) and other airflows 
determined from a forced expiration (West, 1990; 1992) were lower among 
miners who later developed simple CWP category 1/1 or higher. These 
miners also experienced more wheezing at the first medical examination. 
Thus, the results of their study suggested that lung function changes 
may serve as an early indicator of miners who are at increased risk of 
developing simple CWP and PMF and who should be monitored more closely.
    Carta, et al. (1996) have examined the role of dust exposure on the 
prevalence of respiratory symptoms and loss of lung function in a group 
of young Italian coal miners (i.e., mean age at hire 28.9 years, mean 
age at first survey 31.2 years). These miners worked underground and 
were exposed to lignite (i.e., low rank coal) which had a 5-7% sulfur 
content. They were followed for a period of 11 years, from 1983 and 
1993. Carta, et al. (1996) found few abnormalities on miner chest x-
rays taken throughout the 11-year study. However, there was an 
increased prevalence of respiratory symptoms and loss of lung function. 
This was particularly noteworthy since dust exposures were often below 
1.0 mg/m\3\; the cumulative dust exposure for the whole cohort was 6.7 
mg-yr/m\3\ after the first survey. Thus, Carta, et al. (1996) 
demonstrated that miners experience respiratory effects of exposure to 
dust generated from a lower rank coal and at lower concentrations. They 
have recommended yearly measurements of lung function for miners.
    Lewis, et al. (1996) studied a group of British miners, many of 
whom entered the coal industry in the 1970s. Based upon chest x-rays, 
the miners had no evidence of simple CWP or PMF. The objective of this 
study was to determine whether coal mining (i.e., exposure to 
respirable coal mine dust) is an independent risk factor for impairment 
of lung function. Lewis, et al. (1996) found that there was a loss of 
lung function in miners (smokers and nonsmokers), particularly among 
miners who were under approximately 55 years of age. For miners who 
smoked, there was a greater loss of lung function than in nonsmoking 
miners with the same level of exposure to respirable coal mine dust. 
Above age 55, the loss of lung function was similar for miners and 
their controls, although all smokers continued to exhibit a greater 
loss of lung function than nonsmokers. Lewis, et al. (1996) concluded 
that the deficits in lung function may occur in the absence of simple 
CWP and PMF, and independent from the effects of smoking.
    There have been two recent mortality studies that have demonstrated 
a relationship between exposure to respirable coal mine dust and 
development of COPD. This association was reported by Kuempel, et al. 
(1995) in the U.S., and by Meijers, et al. (1997) in the Netherlands. 
These two groups of investigators have reported that occupationally-
induced COPD (e.g., chronic bronchitis, emphysema) can occur in miners, 
with or without the presence of simple CWP or PMF. They also found that 
the risk of premature mortality from COPD was elevated among miners and 
could be separated from the effects of smoking and age.
    Kuempel, et al. (1995) found an increase in relative risk (RR) of 
premature mortality from COPD among U.S. coal miners who participated 
in the NSCWP from 1969 through 1971. In their data analysis, the 
exposure-response relationship was evaluated using the Cox proportional 
hazards model. This model assumes that the hazard ratio between 
nonexposed and exposed groups does not significantly change with time. 
When fitting a curve to the data (e.g., log-linear), cumulative 
exposure was expressed as a categorical or continuous variable. Due to 
model limitations (e.g., less statistical power, influence of category 
scheme, use of lowest exposure group for comparisons vs. use of non-
exposed group), Kuempel, et al. (1995) believed that the exposure data 
should be expressed as a continuous variable. If, for example, the 
cumulative exposure was 90 mg-yr/m\3\ (i.e., 2 mg/m\3\ for 45 years), 
then the relative risk of mortality from chronic bronchitis or 
emphysema was 7.67. Kuempel, et al. (1995) also showed that relative 
risk decreased with lower cumulative exposures (i.e., below 90 mg-yr/
m\3\) and increased with higher cumulative exposures (i.e., above 90 
mg-yr/m\3\). Thus, these investigators demonstrated a statistically 
significant exposure-response relationship for COPD.
    Meijers, et al. (1997) have shown, among Dutch miners, reductions 
in lung volumes and capacities are good predictors of the increased 
risk of premature mortality from COPD. For example, a diminished forced 
expiratory volume in one second (FEV1) or a diminished ratio 
of the FEV1 to the forced vital capacity \10\ (FVC) (i.e., 
FEV1/FVC) upon medical examination was associated with a 
significantly increased standardized mortality ratio (SMR) for COPD 
(322 and 212, respectively). In other words, miners with diminished 
lung capacity based on FEV1 were two to three times more 
likely to die prematurely due to COPD than miners who had normal lung 
function. In contrast, SMRs for COPD were not

[[Page 42159]]

significantly increased in miners with normal lung volumes and 
capacities. These data support prior conclusions of Seixas, et al. 
(1992, 1993) and Attfield and Hodous (1992) based on morbidity studies.
---------------------------------------------------------------------------

    \10\ Forced vital capacity (FVC) is the total volume of gas that 
can be exhaled with a forced expiration after a full inspiration; 
The vital capacity measured with a FVC may be less than that 
measured with a slower exhalation (West, 1992).
---------------------------------------------------------------------------

VI. Quantitative Risk Assessment

    As mentioned previously, in addition to this proposed notice of 
rulemaking, today's Federal Register contains another NPRM, 
Determination of Concentration of Respirable Coal Mine Dust, RIN 1219-
AB18. In combination, these rules present MSHA's strengthened plan to 
meet the Mine Act's requirement that a miner's exposure to respirable 
coal mine dust be at or below the applicable standard on each and every 
shift. MSHA's improved program to eliminate overexposures on each and 
every shift includes the simultaneous implementation of an improved 
tool to identify overexposures (i.e., inspectors use of single, full-
shift samples for noncompliance determinations) and this proposed 
regulation, requiring operators to verify ventilation plans in 
underground coal mines.
    Having reviewed the reported health effects associated with 
exposure to coal mine dust, we have evaluated the evidence to determine 
whether the current regulatory strategy can be improved. The criteria 
for this evaluation is established by the Mine Act under section 
101(a)(6)(A) [30 U.S.C. 811(a)(6)(A)] which provides that:

    The Secretary, in promulgating mandatory standards dealing with 
toxic materials or harmful physical agents under this subsection, 
shall set standards which most adequately assure on the basis of the 
best available evidence that no miner will suffer material 
impairment of health or functional capacity even if such miner has 
regular exposure to the hazards dealt with by such standard for the 
period of his working life.

    Based on Court interpretations of similar language under the 
Occupational Safety and Health Act, there are three questions that must 
be addressed: (1) Whether health effects associated with the current 
pattern of overexposures on individual shifts constitute a material 
impairment to miner health or functional capacity; (2) whether the 
current pattern of overexposures on individual shifts places miners at 
a significant risk of incurring any of these material impairments; and 
(3) whether the proposed rules would substantially reduce those risks.
    The criteria for evaluating the health effects evidence do not 
require scientific certainty. The need to evaluate risk does not mean 
that an agency is placed into a ``mathematical straightjacket.'' See 
Industrial Union Department, AFL-CIO v. American Petroleum Institute, 
448 U.S. 607, 100 S.Ct 2844 (1980), otherwise known as the ``Benzene'' 
decision. When regulating on the edge of scientific knowledge, 
certainty may not be possible and,

so long as they are supported by a body of reputable scientific 
thought, the Agency is free to use conservative assumptions in 
interpreting the data * * * risking error on the side of 
overprotection rather than underprotection (Id at 656).

The statutory criteria for evaluating the health evidence do not 
require MSHA and NIOSH to wait for absolute certainty and precision. 
MSHA and NIOSH are required to use the ``best available evidence'' 
(section 101(a)(6)(A) of the Mine Act (30 U.S.C. 811(a)(6)(A)).
    As explained earlier, MSHA's objective in strengthening the 
requirements for verifying the effectiveness of dust control plans, and 
in enforcing effective plans through the new enforcement policy 
proposed in this notice, is to ensure that no miner is exposed to an 
excessive concentration (i.e., a concentration in excess of the 
applicable standard) of respirable dust on any individual shift. Annual 
inspector samples have demonstrated overexposures on individual shifts 
in many mines. Data compiled from the far more frequent, bimonthly, 
operator sampling program show that in many mines, the applicable dust 
standard is exceeded on a substantial percentage of the production 
shifts. This pattern has persisted for many years, and, since 
individual shift excursions above the applicable standard are permitted 
under the existing program, the same pattern can be expected to 
continue over the working lifetime of affected miners--unless an effort 
is made to eliminate excess exposures on individual shifts. In this 
quantitative risk assessment (QRA), MSHA will demonstrate that reducing 
coal mine dust concentrations, over a 45-year occupational lifetime, to 
no more than the applicable standard on just that percentage of shifts 
showing an excess, thereby lowering the cumulative exposure to 
respirable coal mine dust than would otherwise occur, would 
significantly reduce the risk of both simple CWP and PMF among miners. 
We have estimated the health benefits of the two rules arising from the 
elimination of overexposures on all shifts at only those MMUs 
exhibiting a pattern of recurrent overexposures on individual 
shifts.\11\
---------------------------------------------------------------------------

    \11\ By ``exhibiting a pattern of recurrent overexposures,'' 
MSHA means that, at a 95-percent confidence level, the applicable 
standard is exceeded on at least [six] shifts per year. Using a 
different definition of ``recurrent pattern of overexposures'' in 
these analyses would change the estimate of the reduction in risk 
and associated benefits. For example, if the definition were that 
four or more DO bimonthly exposure measurements exceeded the 
applicable standard, we could state, with 95% confidence, that the 
standard was exceeded on at least 20 shifts in a year of 384 shifts. 
This would reduce the population for whom we are estimating 
benefits, and decrease the estimated number of prevented cases by 
19%.
---------------------------------------------------------------------------

    Based on 1999 operator data, there were 704 MMUs (out of 1,251 
total) at which dust concentrations for the designated occupation (DO) 
exceeded the applicable standard on at least two of the sampling shifts 
(MSHA, Datafile:Operator.ZIP).\12, 13\ MSHA considers these 704 MMUs, 
representing more than one-half of all underground coal miners working 
in production areas, to have exhibited a pattern of recurrent 
overexposures. Valid operator DO samples were collected on a total of 
18,569 shifts at these 704 MMUs, and the applicable standard was 
exceeded on 3,977 of these shifts, or 21.4 percent. For this 21.4 
percent, the mean excess above the standard, as measured for the DO 
only, was 1.04 mg/m\3\.
---------------------------------------------------------------------------

    \12, 13\ MSHA estimates an MMU average of 384 production shifts 
per year. Since mine operators are required to submit five valid 
designated operator (DO) samples to MSHA every two months, there 
would typically be 30 valid DO samples--representing 30 of the 384 
production shifts--for each MMU that was in operation for the full 
year. If dust concentrations on two or more of the sampled shifts 
exceeded the standard, then it follows, at a 95-percent confidence 
level, that the standard was exceeded on at least [six] shifts over 
the full year.
---------------------------------------------------------------------------

    These results are based on a large number of shifts (an average of 
approximately 26 at each of the 704 MMUs). Therefore, assuming 
representative operating conditions on these shifts, the results can be 
extrapolated to all production shifts, including those that were not 
sampled, at these same 704 MMUs. With 99-percent confidence, the 
overall percentage of production shifts on which the DO sample exceeded 
the standard was between 20.6 percent and 22.2 percent for 1999. At the 
same confidence level, again assuming representative operating 
conditions, the overall mean excess on noncompliant shifts at these 
MMUs was between 0.96 mg/m\3\ and 1.12 mg/m\3\. If operators tend to 
reduce production and/or increase dust controls on sampled shifts (as 
some commenters to the previous single, full-shift sample rulemaking 
and the Dust Advisory Committee have alleged) then the true values 
could be

[[Page 42160]]

higher than the upper endpoints of these 99-percent confidence 
intervals.
    In 1998, MSHA attempted to enforce compliance on individual shifts. 
Therefore, to compare the 1999 pattern of excess exposures on 
individual shifts to that of previous years under the current 
enforcement policy, MSHA examined the regular bimonthly DO sample data 
submitted to MSHA by mine operators in the eight years from 1990 
through 1997. The same three parameters were considered as discussed 
above for 1997: (1) The percentage of MMUs exhibiting a pattern of 
recurrent overexposures, as indicated by at least two of the valid 
measurements above the applicable standard in a given year; (2) for 
those and only those MMUs exhibiting recurrent overexposures, the 
overall percentage of production shifts on which the DO was 
overexposed, as estimated by the percentage of valid measurements above 
the applicable standard; and (3) for the MMUs identified as exhibiting 
recurrent overexposures, the mean excess above the applicable standard, 
as calculated for just those valid measurements that exceeded the 
applicable standard in a given year.
    Although MSHA found minor differences between individual years, 
there was no statistically significant upward or downward trend in any 
of these three parameters over the 1990-1997 time period (see Table VI-
1). In 1999, however, there was a significant decrease in the average 
excess above the applicable standard (Parameter #3) for MMUs exhibiting 
recurrent overexposures. MSHA attributes this decrease to two important 
changes in the Agency's inspection program, beginning near the end of 
1998. These changes, which both resulted in increased inspector 
presence, were: (1) An increase in the frequency of MSHA dust sampling 
at underground coal mines; and (2) initiation of monthly spot 
inspections at mines that were experiencing difficulty in maintaining 
consistent compliance with the applicable dust standard.

      Table VI-1.--1990-1997, Distribution of Parameters of Annual Overexposure to Respirable Coal Mine Dust
----------------------------------------------------------------------------------------------------------------
                                                                   Parameter #1    Parameter #2    Parameter #3
                            1990-1997                                (percent)       (percent)       (mg/m\3\)
----------------------------------------------------------------------------------------------------------------
Number of Years.................................................           8               8              8
Median..........................................................          52.6            20.5            1.23
Mean (Standard Error)...........................................          50.9            20.6            1.25
                                                                          (1.62)          (0.32)         (0.020)
----------------------------------------------------------------------------------------------------------------
Parameter #1: Percentage of MMUs exhibiting a pattern of recurrent overexposures.
Parameter #2: For those MMUs exhibiting a pattern of recurrent overexposures, the percentage of production
  shifts on which the DO was overexposed.
Parameter #3: For those MMUs exhibiting a pattern of recurrent overexposures, the mean excess above the
  applicable standard among valid DO measurements that exceeded the applicable standard.

    MSHA invites public comment on whether these three parameters, 
based on operators' 1999 samples, under-represent or over-represent the 
frequency and/or magnitude of excessive dust concentrations on all 
individual shifts--including those that are not sampled. These data 
suggest that, unless changes are made to enforce the dust standard on 
every shift, the same average pattern of overexposures observed in 1999 
will persist into the future. Therefore, we conclude that without the 
proposed changes:
     Approximately 56 percent of all MMUs would continue to 
have a pattern of recurrent overexposures on individual shifts;
     At those MMUs with recurrent overexposures, full shift 
average respirable dust concentrations for the DO would continue to 
exceed the applicable standards on about 21 percent of all production 
shifts;
     Among those shifts on which DO exposure exceeds the 
applicable standards, the mean excess for the DO would continue to be 
approximately 1.0 mg/m\3\.
    If all overexposures on individual shifts are eliminated, the 
reduction in total respirable coal mine dust inhaled by a miner over a 
working lifetime will depend on the following factors: the average 
volume of air inhaled on each shift that would otherwise have exceeded 
the applicable standard, the degree of reduction in respirable dust 
concentration in the air inhaled on such shifts, and the number of such 
shifts per working lifetime. If a miner inhales ten cubic meters of air 
on a shift (U.S. EPA, 1980), reducing the respirable dust concentration 
in that air by 1.0 mg/m\3\ would result in 10 mg less dust inhaled on 
that shift alone. Assuming the miner works 240 shifts per year, then 
reducing inhaled respirable dust by an average of 10 mg on 21 percent 
of the shifts would reduce the total dust inhaled by 504 mg per year, 
or nearly 22,700 mg over a 45-year working lifetime:

1.0 mg per m\3\ of inhaled air
 x  10 m\3\ inhaled air per shift
 x  50.4 affected shifts (i.e., 21% of 240) per work year
 x  45 work years per working lifetime
= 22,680 mg less dust inhaled per working lifetime.

    The Secretaries invite comments on the health benefits expected 
from reducing the total coal mine dust inhaled over a working lifetime 
by this amount.
    In Section V, the strengths and weaknesses of various 
epidemiological studies were presented, supporting the selection of 
Attfield and Seixas (1995) as the study that provides the best 
available estimate of material health impairment with respect to CWP 
and PMF. Two of the distinguishing qualities of this study are the 
dose-response relationship over a miners' lifetime and the fact that 
these data best represent the recent conditions experienced by miners 
in the U.S. Using this relationship it is possible to evaluate the 
impact on risk of both simple CWP and PMF expected from bringing dust 
concentrations down to or below the applicable standard on every shift. 
This is the only contemporary epidemiological study of CWP and PMF 
providing such a relationship.
    Attfield and Seixas used two or three B readers to identify the 
profusion of opacities using the ILO classification scheme. If three 
readings were available, the median value was used. If two readings 
were available, the higher of the two ILO categories was recorded. 
Eighty radiographs were eliminated because only one reading was 
available. The most inclusive category of CWP 1+ includes 
simple CWP, categories 1, 2, 3, as well as PMF. Category CWP 
2+ does not include simple CWP, category 1, but does include 
the more severe simple

[[Page 42161]]

CWP categories, 2 and 3, as well as PMF. The third category used in 
their report was PMF, denoting any category of large opacities.
    Attfield and Seixas (1995) provided logistic regression models for 
the prevalence for CWP 1+, CWP 2+ and PMF as a 
function of cumulative dust exposure, expressed as the product of dust 
concentration measured in the mine atmosphere and duration of exposure 
at that concentration. These models can be used to estimate the impact 
on miners' risk of both simple CWP and PMF of reducing lifetime 
accumulated exposure by eliminating excessive exposures on a given 
percentage of individual shifts.
    At the MMUs being considered (those exhibiting a pattern of 
recurrent overexposures), bringing dust concentrations down to no more 
than the applicable standard on each and every production shift would 
reduce DO exposures on the affected shifts by an average of 1.04 mg/
m\3\. Assuming this average reduction applies to only 21 percent of the 
shifts, the effect would be to reduce cumulative exposure, for each 
miner exposed at or above the DO level, by 0.22 mg-yr/m\3\ over the 
course of a working year (i.e., 21 percent of shifts in one year, times 
1.04 mg/m\3\ per shift). Therefore, over a 45-year working lifetime, 
the benefit to each affected miner would, on average, amount to a 
reduction in accumulated exposure of approximately 10 mg-yr/m\3\ (i.e., 
45 years times 0.22 mg-yr/m\3\ per year). If, as some miners have 
testified, operator dust samples submitted to MSHA tend to under-
represent either the frequency or magnitude (or both) of individual 
full shift excursions above the applicable standard, then eliminating 
such excursions would provide a lifetime reduction of even more than 10 
mg-yr/m\3\ for each exposed miner.
    The Attfield and Seixas models predict the prevalence of CWP 
1+, CWP 2+, and PMF for miners who have 
accumulated a given amount of exposure, expressed in units of mg-yr/
m\3\, by the time they attain a specified age. Benefits of reducing 
cumulative exposure can be estimated by calculating the difference 
between predictions with and without the reduction. For example, 
suppose a miner begins work at age 20 and retires at age 65. By the 
year of retirement, that miner is expected to accumulate nearly 10 mg-
yr/m\3\ less exposure if individual shift excursions are eliminated. 
For 65-year-old miners, reducing accumulated dust exposure by a total 
of 10 mg-yr/m\3\ reduces the predicted prevalence of CWP 1+ 
by at least 11 per thousand (See Table VI-2).
    This 11 per thousand, however, applies only to miners of age 65. 
The Attfield and Seixas models provide different predictions for each 
year of age that a miner attains. The predicted benefit turns out to be 
smaller for younger miners and larger for older miners. This is partly 
because younger miners will have accumulated less exposure reduction 
from the proposed changes, and partly because the Attfield and Seixas 
models depend directly on age as well as on cumulative exposure. The 
health effects of recurrent overexposures can occur long after the 
overexposures occurred. Even after a miner retires and is no longer 
exposed to respirable coal mine dust, the extra risk attributable to an 
extra 10 mg-year/m\3\, accumulated earlier, continues to increase with 
age. Consequently, the benefit to be gained from eliminating individual 
shift excursions also continues to increase after a miner is no longer 
exposed. For example, assuming no additional exposure after age 65, the 
predicted reduction in average prevalence of CWP1+ increases 
from 12 per thousand at age 65 to 17 per thousand at age 70. 
Presumably, the increasingly greater predicted reduced risk of disease 
after age 65 is due to the latent effects of the reduction in earlier 
exposure.
    To project the benefits of the two rules expected from eliminating 
overexposures on individual shifts, MSHA applied the Attfield and 
Seixas models to a hypothetical population of miners who, on average, 
begin working at age 20 and retire at age 65, assuming different 
lifetimes. The risks for three different ages have been presented to 
show a range of risk depending on the lifetime: 65, 73, and 80 years. 
During the 45 ``working years'' between 20 and 65, the lifetime benefit 
accumulates at a rate of 0.22 mg-yr/m\3\ of reduced exposure per year, 
reaching a maximum of about 10 mg-yr/m\3\ at age 65. Between ages 65 
and 80, the accumulated reduction in dust exposure remains at an 
estimated average of 10 mg-yr/m\3\, but the benefit in terms of both 
simple CWP and PMF risk continues to increase, as explained previously.
    The expected lifetime for all American males conditional on their 
having reached 20 years of age, is 73 years (calculated from: U.S. 
Census March 1997, Table 18; U.S. Census March 1997, Table 119).\14\ On 
average, the best estimate of the lifetime benefit to exposed miners is 
expressed by the reduction in prevalence of disease at age 73. Carrying 
out the calculation at a 73-year average lifetime, MSHA expects that, 
at the MMUs under consideration, bringing dust concentrations down to 
no more than the applicable standard on each shift will:
---------------------------------------------------------------------------

    \14\ Since females have a greater life expantancy than males, 
expected benefits would increase if the production of female miners 
were to increase substantially in the future.
---------------------------------------------------------------------------

     Reduce the combined risk of simple CWP and PMF by at least 
18 cases per 1000 affected DO miners; \15\
---------------------------------------------------------------------------

    \15\ ``affected DO miners'' include all miners who work at the 
56-percent of MMUs under consideration and who are exposed to dust 
concentrations similar to the DO over a 45-year working lifetime.
---------------------------------------------------------------------------

     Reduce the combined risk of simple CWP (category 2 and 3) 
and PMF by at least 9.8 cases per 1000 affected DO miners;
     Reduce the risk of PMF by at least 5.1 cases per 1000 
affected DO miners.
    Presented in the first row of Table VI-2 are the average reductions 
in risk for simple CWP and PMF combined, and PMF alone, over an 
occupational lifetime, among affected DO miners who live to ages 65, 
73, and 80, who have worked at an MMU exhibiting a pattern of recurrent 
overexposures. Across health outcomes, the benefit due to the predicted 
reduction in cumulative exposure to respirable coal mine dust, through 
limiting miners' exposure to no more than the applicable standard on 
each and every shift, increases with age.
    When the dust concentration measured for the DO exceeds the 
applicable standard, measurements for at least some of the other miners 
may also exceed the standard on the same shift, though usually by a 
lesser amount. Furthermore, although the DO represents the occupation 
most likely to receive the highest exposure, other miners working in 
the same MMU may be exposed to even higher concentrations than the DO 
on some shifts. Therefore, in addition to the affected DO miners, there 
is a population of other affected miners who are also expected to 
experience a significant reduction in risk as a result of eliminating 
overexposures on their individual shifts.
    To estimate how many miners other than the DO would be 
substantially affected, MSHA examined the results from all valid dust 
samples collected by MSHA inspectors in underground MMUs during 1999 
(MSHA, Data file: Inspctor.zip). Within each MMU, the inspector 
typically takes one full-shift sample on the DO and, on the same shift, 
four or more additional samples representing other occupations. On 896 
shifts, at a total of 450 distinct MMUs, the DO measurement exceeded 
the applicable standard and there were at least four valid measurements 
for other

[[Page 42162]]

occupations available for comparison. There was an average of 1.2 non-
DO measurements in excess of the standard on shifts for which the DO 
measurement exceeded the standard.\16\ For non-DO measurements that 
exceeded the standard on the same shift as a DO measurement, the mean 
excess above the standard was approximately 0.8 mg/m\3\.\17\
---------------------------------------------------------------------------

    \16\ With 95-percent confidence, on shifts for which the DO 
measurement exceeds the standard, the mean number of other 
occupational measurements also exceeding the standard is at least 
1.11.
    \17\ With 95-percent confidence, the mean excess is at least 
0.72 mg/m\3\.
---------------------------------------------------------------------------

    Combining these results with the 21-percent rate of excessive 
exposures observed for the DO on individual shifts, it is reasonable to 
infer that, at the MMUs under consideration, an average of 1.2 other 
miners, in addition to the one classified as DO, is overexposed on at 
least 21 percent of all production shifts. Over the course of a working 
year, the reduction in exposure expected for these other miners is 0.17 
mg-yr/m\3\ (i.e., 21 percent of one year, times 0.8 mg/m\3\).
    To assess the reduction in risk expected from eliminating all 
single-shift exposures for faceworkers experiencing lower exposures 
than the DO, MSHA again applied the Attfield and Seixas models to 
miners who begin working at age 20, retire at age 65, assuming various 
lifetimes: 65, 73, and 80 years. This time, however, the resulting 
decrease in predicted prevalence was multiplied by 1.2/7=0.171, to 
reflect the fact that the assumed rate of overexposure applies, on 
average, to about 17 percent of the faceworkers not classified as the 
DO.\18\
---------------------------------------------------------------------------

    \18\ There are an estimated 7 non-DO miners for each DO miner, 
and an average of 1.2 of these 7 miners are overexposed.
---------------------------------------------------------------------------

    In the second row of Table VI-2, we see that over an occupational 
lifetime, the beneficial average reduction in risk for simple CWP and 
PMF combined, and for PMF alone, increases with age. However, the 
magnitude of the risk reduction is smaller for the affected non-DOs 
than the affected DOs. This is expected because the estimated 
probability that a non-DO will be overexposed on a given shift is only 
17 percent of the corresponding probability for the DO. Based on this 
calculation for the MMUs under consideration, the predicted reduction 
in risk for faceworkers other than the DO who live an expected lifetime 
of 73 years is at least: 2.3 fewer cases of PMF or simple CWP per 
thousand affected miners; 1.3 fewer cases of PMF or simple CWP, 
categories 2 or 3, per thousand affected miners; and 0.7 fewer cases of 
PMF per thousand affected miners.
    Various data, assumptions and caveats were used to conduct the 
quantitative risk assessment and benefits analyses. Therefore, we 
request any information which would enable us to conduct more accurate 
analyses of the estimated health benefits of the single, full-shift 
sample rule and plan verification rule, both individually and in 
combination.

      Table VI-2.--By Age, Average Reduction in Risk of Occupational Respiratory Disease per 1,000 Affected
      Underground Coal Miners Expected To Result From Implementation of Single, Full-Shift Sample and Plan
                                                  Verification
----------------------------------------------------------------------------------------------------------------
                                 Reduction in risk of occupational respiratory disease per 1,000 affected miners
                                --------------------------------------------------------------------------------
                                       Simple CWP,\a\        Simple CWP (categories 2             PMF
                                 (categories 1, 2 or 3) or         or 3) or PMF       --------------------------
         Type of miner                    PMF \b\          ---------------------------            Age
                                ---------------------------            Age            --------------------------
                                            Age            ---------------------------
                                ---------------------------                               65       73       80
                                    65       73       80       65       73       80
----------------------------------------------------------------------------------------------------------------
Affected Designated Occupation      11.0     18.0     25.0      3.7      9.8     21.0      1.8      5.1     12.0
 Miners \c\....................
Affected Non-Designated              1.4      2.3      3.3      0.5      1.3      2.7      0.2      0.7     1.5
 Occupation Miners \d\.........
----------------------------------------------------------------------------------------------------------------
\a\ Simple CWP: Simple coal workers' pneumoconiosis.
\b\ PMF: Progressive massive fibrosis.
\c\ Affected Designated Occupation (DO) Miners: Includes all miners who work at the 56-percent of the Mechanized
  Mining Units under consideration and who are exposed to dust concentrations similar to the DO, over a 45-year
  occupational lifetime.
\d\ Affected Non-Designated Occupation (Non-DO) Miners: Includes all underground faceworkers under consideration
  who are not classified as the DO.

VII. Significance of Risk

    The criteria for evaluating the evidence to determine whether these 
proposed standards improve the regulatory strategy for controlling 
exposures to respirable coal mine dust are established by the Mine Act 
pursuant to section 101(a)(6)(A) (30 U.S.C. 811(a)(6)(A))which provides 
that:

    The Secretary, in promulgating mandatory standards dealing with 
toxic materials or harmful physical agents under this subsection, 
shall set standards which most adequately assure on the basis of the 
best available evidence that no miner will suffer material 
impairment of health or functional capacity even if such miner has 
regular exposure to the hazards dealt with by such standard for the 
period of his working life.

    Based on Court interpretations of similar language under the 
Occupational Safety and Health Act, there are three questions that must 
be addressed: (1) Whether health effects associated with the current 
pattern of overexposures on individual shifts constitute a material 
impairment to miner health or functional capacity; (2) whether the 
current pattern of overexposures on individual shifts places miners at 
a significant risk of incurring any of these material impairments; and 
(3) whether the proposed rules would substantially reduce those risks.
    The statutory criteria for evaluating the health evidence do not 
require MSHA to wait for absolute certainty and precision. MSHA is 
required to use the ``best available evidence'' (section 101(a)(6)(A) 
of the Mine Act (30 U.S.C. 811(a)(6)(A)). The need to evaluate risk 
does not mean that an agency is placed into a ``mathematical 
straightjacket.'' See Industrial Union Department, AFL-CIO v. American 
Petroleum Institute, 448 U.S. 607, 100 S.Ct 2844 (1980), otherwise 
known as the ``Benzene'' decision. When regulating on the edge of 
scientific knowledge, certainty may not be possible and,

so long as they are supported by a body of reputable scientific 
thought, the Agency is free to use conservative assumptions in 
interpreting the data . . . risking error on the

[[Page 42163]]

side of overprotection rather than underprotection (Id at 656).

    We have taken steps in our quantitative risk assessment to conduct 
a balanced analysis using available data. Some of our assumptions were 
conservative, others were not.\19\
---------------------------------------------------------------------------

    \19\ Following terminology used in the Benzene Decision, a 
``conservative'' assumption is one that results in more protection 
for miners than a less conservative assumption. Therefore, estimated 
benefits are greater under assumptions that are ``conservative'' in 
this sense.
---------------------------------------------------------------------------

    In identifying the number and percentage of MMUs exhibiting a 
pattern of recurrent overexposures on individual shifts we chose to 
include only those MMUs with two or more 1999-operator bimonthly 
samples in excess of the applicable standard, rather than the 
population of MMUs with any overexposures.\20\ Also, the Quantitative 
Risk Assessment estimates of reduction in risk are averages across MMUs 
exhibiting a pattern of recurrent overexposures. For those miners who 
work at mines exhibiting a pattern of recurrent overexposures which 
differs from the one applied in the Quantitative Risk Assessment, their 
reduction in risk would be more than or less than the expected average, 
depending on whether or not their overexposures are at a higher or 
lower than average rate and intensity.
---------------------------------------------------------------------------

    \20\ By ``exhibiting a pattern of recurrent overexposures,'' 
means that, at a 95-percent confidence level, the applicable 
standard is exceeded on at least six shifts per year.
---------------------------------------------------------------------------

    Another important decision impacting choice in this risk assessment 
involves the use of the traditional coal miner work schedule of 48-
weeks per year. Many of today's miners work longer hours per day, 
month, and year than the traditional work schedule. These longer work 
hours increase miners' cumulative exposure to respirable coal mine dust 
beyond the parameters of exposure used in our estimates of risk. Even 
so, to the extent that a proportion of miners may have a more limited 
work schedule (and occupational exposure), either in number of years, 
weeks per year, or hours per week, their expected benefit would have to 
be adjusted downward, all other variables being constant.
    Also, because of heavy, physical work, some miners may work at 
ventilatory rates in excess of the above-cited 10 cubic meters per 8-
hour shift; an estimate of this ventilatory rate is 13.5 cubic meters 
per 8-hour shift (ICRP, 1994). The sub-population of miners with higher 
breathing rates would inhale more respirable coal mine dust than would 
otherwise occur given the same environmental exposures, thereby 
increasing their risks for the development of simple CWP and PMF.
    In the QRA, to estimate average reduction in exposure, we chose the 
best available data sets: 1999 operator bimonthly samples for DOs and 
NDOs, respectively. Currently, both operator bimonthly and inspector 
samples \21\ may be taken on production shifts that may not reflect 
typical production levels. \22\ Although other factors may mediate the 
amount of airborne respirable dust such as, ventilation and water 
sprays, on average, higher production is correlated with increased 
quantities of airborne respirable coal mine dust (Webster, et al., 
1990; Haney, et al., 1993; O'Green, et al., 1994). Some previous 
commenters and the Dust Advisory Committee have alleged that operators 
tend to reduce production and/or increase dust controls on sampled 
shifts. To the extent that our values underestimate the true reduction 
in respirable coal mine dust exposures, we have underestimated the 
benefits of these rules.
---------------------------------------------------------------------------

    \21\ Valid MSHA inspector samples require production to be at 
least 60-percent of the average production for the last 30-days. 
Valid operator bimonthly samples must be taken on a normal 
production shift (i.e., a production shift during which the amount 
of material produced in an MMU is at least 56 percent of the average 
production reported for the last set of five valid samples) (30 CFR 
70.101).
    \22\ Therefore assuming representative operating conditions on 
these shifts, in our QRA the results were extrapolated to all 
production shifts, including those that were not sampled, at those 
same 704 MMUs.
---------------------------------------------------------------------------

    Based on MSHA's and NIOSH's experience and expertise, and previous 
comments, we believe the production levels observed on sampling shifts 
are indeed lower than typical (See discussion in Benefits section). We 
also believe at some MMUs, more engineering controls at higher levels 
of efficacy are used during sampling shifts than on the majority of 
shifts (See discussion in Benefits section). Thus, it is reasonable to 
conclude that the number of MMUs exhibiting a pattern of recurrent 
overexposures is greater than the 704 captured in this Quantitative 
Risk Assessment. Furthermore, the severity and rate of overexposures to 
respirable coal mine dust among the 704 MMUs exhibiting a pattern of 
recurrent overexposures are probably also greater than we have 
estimated. We have derived our best estimate of the reduced risk using 
the best available data. Yet due to limitations in the data, we believe 
that we have underestimated the magnitude and frequency of typical 
respirable coal mine exposures. To the extent that our values 
underestimate the true reduction in respirable coal mine dust 
exposures, we have underestimated the benefits of these rules.
    Other aspects of our risk assessment methodology reflect more 
conservative choices including the selection of an occupational 
lifetime of 45-years. Various factors may affect the consistency of the 
type and duration of jobs miners hold and hence their associated 
cumulative exposure levels. For example, some miners who lose their 
jobs upon mine closure are employed by other mines, sometimes in less-
exposed jobs. Some miners may chose to move from job to job over their 
careers at underground coal mines, sometimes preferring positions away 
from the mining face. Moreover, if the trend of increasing 
mechanization continues, there will be fewer miners, and for some of 
them, their occupational lifetimes will be shorter.
    For reasons already explained, we believe these choices are 
appropriate for this risk assessment. We also recognize that use of the 
most conservative approach at every step of the risk assessment 
analysis could produce mathematical risk estimates which, because of 
the additive effect of multiple conservative assumptions, may overstate 
the likely risk. We believe this QRA for simple CWP and PMF strikes a 
reasonable balance based on available data. To the extent that we may 
have underestimated the magnitude of overexposures which would be 
prevented, we believe the actual benefits to be greater than we have 
estimated.
    It should be noted that reductions in the prevalence of simple CWP 
and PMF attributable to eliminating individual shift overexposures are 
not expected to materialize immediately after the overexposures have 
been substantially reduced or eliminated. Because these diseases 
typically arise after many years of cumulative exposure, allowing for a 
period of latency, the beneficial effects of reducing exposures are 
expected to become evident only after a sufficient time has passed that 
the reduction in cumulative exposure could have its effect. The total 
realized benefits would not be fully evident until after the youngest 
of today's underground coal miners retire.

VIII. Feasibility Issues

    Section 101(a)(6)(A) of the Mine Act (30 U.S.C. 811(a)(6)(A)) 
requires the Secretary of Labor to set standards which most adequately 
assure, on the basis of the best available evidence, that no miner will 
suffer material impairment of health or functional capacity even if 
such miner has regular exposure to such hazards dealt with by

[[Page 42164]]

such standard over his or her working lifetime. Standards promulgated 
under this section must be based upon research, demonstrations, 
experiments, and such other information as may be appropriate. MSHA, in 
setting health standards, is required to achieve the highest degree of 
health and safety protection for the miner, and must consider the 
latest available scientific data in the field, the feasibility of the 
standards, and experience gained under this and other health and safety 
laws.
    In relation to promulgating health standards, the legislative 
history of the Mine Act states that:

    * * * This section further provides that ``other 
considerations'' in the setting of health standards are ``the latest 
available scientific data in this field, the feasibility of the 
standards, and experience gained under this and other health and 
safety laws.'' While feasibility of the standard may be taken into 
consideration with respect to engineering controls, this factor 
should have a substantially less significant role. Thus, the 
Secretary may appropriately consider the state of the engineering 
art in industry at the time the standard is promulgated.
* * * * *
Similarly, information on the economic impact of a health standard 
which is provided to the Secretary of Labor at a hearing or during 
the public comment period, may be given weight by the Secretary. In 
adopting the language of section 102(a)(5)(A), the Committee wishes 
to emphasize that it rejects the view that cost benefit ratios alone 
may be the basis for depriving miners of the health protection which 
the law was intended to insure.

S. Rep. No. 95-181, at 21-22 (1977), reprinted in 1977 U.S.C.C.A.N. 
3421-22.
    In American Textile Manufacturers' Institute v. Donovan, 452 U.S. 
490, 508-509 (1981), the Supreme Court defined the word ``feasible'' as 
``capable of being done, executed, or effected.'' The Court further 
stated, however, that a standard would not be considered economically 
feasible if an entire industry's competitive structure were threatened. 
In promulgating standards, hard and precise predictions from agencies 
regarding feasibility are not required.

A. Technological Feasibility

    MSHA believes that the plan verification rule would be 
technologically feasible for the mining industry. An agency must show 
that modern technology has at least conceived some industrial 
strategies or devices that are likely to be capable of meeting the 
standard, and which industry is generally capable of adopting. American 
Iron and Steel Institute v. OSHA, (AISI-II) 939 F.2d 975, 980 (D.C. 
Cir. 1991); American Iron and Steel Institute v. OSHA,  (AISI-I) 577 
F.2d 825 (3d Cir. 1978) at 832-835; and Industrial Union Dep't., AFL-
CIO v. Hodgson, 499 F.2d 467, 478 (D.C. Cir. 1974).
    In designing the plan verification rule, MSHA has taken into 
account its experience and those of the operators to ensure that the 
rule provides additional protection from occupational exposure to 
respirable coal mine dust using current compliance technology (while 
encouraging technological improvements). For this reason, MSHA believes 
the proposed plan verification rule is technologically feasible. MSHA 
requires mine operators to utilize all feasible engineering or 
environmental controls, which are specified in the mine ventilation 
plan, to maintain concentrations of respirable dust in the work 
environment of MMUs at or below the applicable dust standard. Mine 
operators therefore would not be required to implement engineering or 
environmental controls that were not technologically feasible.
    Based on its vast experience in the sampling of respirable dust 
levels in the MMU work environment, MSHA believes that technology is 
currently available to control respirable dust to levels at or below 
the applicable level at MMUs employing continuous and conventional 
methods of mining. However, MSHA recognizes that, unlike other mining 
systems, longwall MMUs may have acute dust problems caused by the face-
ventilation airstream carrying the shearer-generated face dust over the 
miners working downwind along the face. In these high-production 
longwall MMUs, improvements in dust control technology have not kept 
pace with increases in production technology. For this reason, the 
proposed plan verification rule would allow longwall operators who have 
trouble in meeting MSHA's respirable dust standard and who have 
exhausted all feasible engineering and environmental controls to use 
administrative controls or loose-fitting powered air-purifying 
respirators (PAPRs), until other feasible controls become available.

B. Economic Feasibility

    The plan verification rule would clearly be economically feasible 
for the underground coal mining industry since the underground coal 
mining industry would derive net compliance cost savings of 
approximately $2.04 million yearly from the proposed plan verification 
rule. (Although implementing the plan verification rule would cost 
about $4.75 million yearly, there would be the following offsetting 
yearly savings: $2.19 million from reduced mine operator citations 
based on results from inspector single, full-shift samples and 
associated abatement sampling, $1.61 million from reduced mine operator 
citations on results from operators' bi-monthly samples and associated 
abatement sampling, $2.73 million from the elimination of operator bi-
monthly sampling, and $0.27 million from reduced payouts by mine 
operators for Black Lung cases.) Underground coal mine operators would 
also obtain a yearly cost savings of approximately $0.42 million in 
reduced penalty costs associated with the reduction in mine operator 
citations arising from the proposed plan verification rule. The 
proposed plan verification rule would therefore provide a total yearly 
cost savings of about $2.46 million to the underground coal mining 
industry.

IX. Regulatory Impact Analysis

    MSHA's improved program to eliminate overexposures on each and 
every shift includes (1) the simultaneous implementation of the use of 
inspector single, full-shift respirable coal mine dust samples to 
identify overexposures more effectively in both underground and surface 
coal mines (single, full-shift sample), and (2) in underground coal 
mines, verified ventilation plans to maintain miners' respirable dust 
exposure at or below the applicable standard on each and every shift 
(plan verification). The single, full-shift sample NPRM is published 
elsewhere in today's Federal Register. This part of the preamble 
reviews several impact analyses which MSHA is required to provide in 
connection with the proposed plan verification rulemaking. Since 
single, full-shift sample and plan verification are complementary NPRMs 
intended to be promulgated at the same time, the detailed presentation 
of assumptions and estimates for each are available in the same 
Preliminary Regulatory Economic Analysis (PREA)(MSHA, January 2000).
    Assumptions for the requirements of the plan verification rule are 
based upon information provided by MSHA technical personnel. We 
encourage the mining community to provide detailed comments in this 
regard to ensure that plan verification cost assumptions and estimates 
are as accurate as possible.

A. Costs and Benefits: Executive Order 12866

    In accordance with Executive Order 12866, we have prepared a 
detailed PREA of the estimated costs and benefits associated with the 
proposed rule for the underground coal mining sector. We have fulfilled 
this

[[Page 42165]]

requirement for the proposed rule and determined that this rulemaking 
is not a significant regulatory action. The key findings of the PREA 
are summarized below.
1. Compliance Costs
    The proposed plan verification rule would provide yearly net 
compliance cost savings to underground coal mine operators of about 
$2.04 million. Although implementing the proposed rule would cost about 
$4.75 million yearly, there would be offsetting yearly savings of: 
$2.19 million from reduced mine operator citations issued based on MSHA 
inspectors' single, full-shift sample results and the elimination of 
associated underground operator abatement sampling; $1.61 million from 
reduced mine operator citations issued based on bi-monthly sampling 
results and the elimination of associated underground operator 
abatement sampling; $2.73 million resulting from underground operators 
no longer having to perform bi-monthly operator sampling; and $0.27 
million from reduced payouts by mine operators for Black Lung cases.
    Table IX-1 summarizes the estimated net compliance costs by 
provision for underground coal mines, for the following three mine size 
categories: (1) those employing fewer than 20 workers; (2) those 
employing between 20 and 500 workers; and (3) those employing more than 
500 workers.
    In addition to these estimated compliance costs, mine operators 
would derive yearly penalty cost reductions of about $0.4 million (See 
Table IX-1(a)). Penalty costs conventionally are not considered to be a 
cost of a rule (and, in fact, are clearly not a compliance cost) but 
merely a transfer payment from a party violating a rule to the 
government. Therefore, the penalty costs are not included as part of 
the compliance costs of the proposed plan verification rule. These 
penalty costs are relevant, however, in determining the economic 
feasibility of the proposed plan verification rule.
    The derivation of the above cost figures are presented in Chapter 
IV of the PREA that accompanies this rule.

[[Page 42166]]



                                                                                                        Table IX-1.--PV Cost Summary for Underground Coal Mine Operators*
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                   20 Emp.                                  20 Emp. 500                                >500 Emp.                                              Total
                                                            --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                           Detail                             Adj. first   Annualized     Annual        Yearly     Adj. first   Annualized     Annual        Yearly      Adj. first   Annualized     Annual       Yearly     Adj. first   Annualized     Annual        Yearly
                                                              year costs     costs         costs      costs \a\    year costs     costs         costs       costs \a\    Year costs     costs        costs      Costs \a\    year costs     costs         costs       costs \a\
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                             UNDERGROUND COAL MINES
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PV Rule:
    Compliance Costs.......................................   $1,013,905      $70,973      $346,688     $417,661   $7,599,324     $566,960    $3,285,067    $3,852,027     $749,927      $58,653     $420,105     $478,758   $9,363,156     $696,586    $4,051,860    $4,748,446
    Reduced Inspector Citations \b\........................     $234,374      $16,406     -$534,712    -$518,306     $746,981      $52,289   -$1,658,063   -$1,605,774      $33,603       $2,352     -$71,301     -$68,949   $1,014,958      $71,047   -$2,264,076   -$2,193,029
    Reduced Operator Citations \c\.........................     $106,512       $7,456     -$247,790    -$240,334     $596,040      $41,723   -$1,334,380   -$1,292,657      $39,325       $2,753     -$76,901     -$74,148     $741,877      $51,932   -$1,659,071   -$1,607,139
    Eliminate Bi-Mo.--Sampling.............................           $0           $0     -$556,538    -$556,530           $0           $0   -$2,057,540   -$2,057,540           $0           $0    -$113,712    -$113,712           $0           $0   -$2,727,790   -$2,727,790
    Black Lung Savings.....................................           $0           $0      -$32,570     -$32,570           $0           $0     -$217,896     -$217,896           $0           $0     -$15,196     -$15,196           $0           $0     -$265,662     -$265,662
Net PV Rule................................................   $1,354,791      $94,835   -$1,024,922    -$930,345   $8,942,345     $660,972   -$1,982,812   -$1,321,840     $822,855      $63,758     $142,995     $206,753  $11,119,991     $819,565   -$2,864,739  -$2,045,174
--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
*Data from Preliminary Regulatory Economic Analysis Table IV-16, Table IV-63, Table IV-81, Table IV-100, Table IV-105, and Table IV-106. Note that these costs do not include penalty costs, which are shown in Table IX-1(a) in this document.
\a\ Yearly costs equals annualized costs plus annual costs.
\b\ Reduced costs related to: (1) Reduction in citations issued based on MSHA inspector sample results due to better mine ventilation plans arising from PV rule, and (2) reduction in abatement sampling and associated costs due to elimination of bi-monthly operator
  sampling.
\c\ Reduced costs related to: (1) Reduction in citations issued based on operator sample results due to better mine ventilation plans arising from the PV rule, and (2) reduction in abatement sampling and associated costs due to elimination of operator bi-monthly sampling.


[[Page 42167]]


                                Table IX-1(A).--PV Annual Penalty Cost Summary *
                                               [Yearly penalties]
----------------------------------------------------------------------------------------------------------------
                                                                   20
                     Detail                           20 Emp.      Emp. 500 Emp.         Total
                                                                      eq>500
----------------------------------------------------------------------------------------------------------------
                                             Underground Coal Mines
----------------------------------------------------------------------------------------------------------------
PV Rule:
    Reduced Inspector Citations.................        -$28,468       -$202,334         -$5,263       -$236,065
    Reduced Operator Citations..................         -13,309        -160,956          -4,960        -179,225
ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½
Total PV Rule Reduction.........................         -41,777        -363,290         -10,223       -415,290
----------------------------------------------------------------------------------------------------------------
\*\ Data from Preliminary Regulatory Economic Analysis Table IV-16(a), Table IV-82, and Table IV-101.

2. Benefits
    Occupational exposure to excessive levels of respirable coal mine 
dust imposes significant health risks. These include the following 
adverse health outcomes: simple coal worker's pneumoconiosis (simple 
CWP), progressive massive fibrosis (PMF), silicosis, and chronic 
obstructive pulmonary disease (COPD) (e.g., asthma, chronic bronchitis, 
emphysema) (See the Health Effects section for details). Cumulative 
exposure to respirable coal mine dust is the main determinant in the 
development of both simple CWP and PMF although other factors such as 
the percentage of quartz in the respirable dust and the type of coal 
also affect the risk of miners developing simple CWP and PMF (Jacobsen, 
et al., 1977; Hurley, et al., 1987; Kuempel, et al., 1995; Attfield and 
Morring, 1992; Attfield and Seixas, 1995). The true magnitude of 
occupationally induced simple CWP and PMF among today's coal miners is 
unknown, although prevalence estimates are available from various 
surveillance systems. For example, from 1970 to 1995, the prevalence of 
simple CWP and PMF among miners, based on the operator sponsored x-ray 
program, dropped from 11 percent to 3 percent (MSHA, Internal Chart, 
1998). Also, later rounds of the National Study for Coal Worker's 
Pneumoconiosis consistently demonstrated, through prevalence rates in 
the range of 2.9--3.9 percent, that simple CWP and PMF have not been 
eliminated.
    Through the joint promulgation of single, full-shift sample and 
plan verification rules, miners would be further protected from the 
debilitating effects of occupational respiratory disease by limiting 
their exposures to respirable coal mine dust to no more than the 
applicable standard on each and every shift.\23\ Reducing respirable 
coal mine dust concentrations over a 45-year occupational lifetime to 
no more than the applicable standard on just that percentage of shifts 
showing an excess would lower the cumulative exposure, thereby 
significantly reducing the risk of both simple CWP and PMF among 
miners. We have estimated the health benefits of the two rules arising 
from the elimination of overexposures on all shifts at only those MMUs 
exhibiting a pattern of recurrent overexposures on individual shifts.
---------------------------------------------------------------------------

    \23\ For details, see Quantitative Risk Assessment and 
Significance of Risk sections.
---------------------------------------------------------------------------

    Based on 1999 operator data, there were 704 MMUs (out of 1,251) at 
which regular (not abatement) designated occupational (DO) samples 
exceeded the applicable standard on at least two of the sampling shifts 
reported in 1999 (MSHA, Data file:Operator.ZIP). MSHA considers these 
704 MMUs, representing more than one-half of all underground coal 
miners working in production areas, to have exhibited a pattern of 
recurrent overexposures. Based on valid DO operator samples were 
collected on a total of 18,569 shifts at these 704 MMUs; the applicable 
standard was exceeded on 3,977 of these shifts or 21.4 percent.
    At the MMUs being considered (those exhibiting a pattern of 
recurrent overexposures),\24\ bringing dust concentrations down to no 
more than the applicable standard on each and every production shift 
would reduce DO exposures on the affected shifts by an average of 1.04 
mg/m\3\. Assuming this average reduction applies to only 21 percent of 
the shifts, the effect would be to reduce cumulative exposure, for each 
miner exposed at or above the DO level, by 0.22 mg-yr/m\3\ over the 
course of a working year (i.e., 21 percent of shifts in one year times 
1.04 mg/m\3\ per shift). Therefore, over a 45-year working lifetime, 
the benefit to each affected DO miner would, on average, amount to a 
reduction in accumulated exposure of approximately 10 mg-yr/m\3\ (i.e., 
45 years times 0.22 mg-yr/m\3\ per year). If, as some miners have 
testified, operator dust samples submitted to MSHA tend to under-
represent either the frequency or magnitude (or both) of individual 
full-shift excursions above the applicable standard, then eliminating 
such excursions would provide a lifetime reduction of even more than 10 
mg-yr/m\3\ for each exposed miner.
---------------------------------------------------------------------------

    \24\ MSHA estimates an MMU average of 384 production shifts per 
year. Since miner operators are required to submit five valid 
designated operator (DO samples to MSHA every two months, there 
would typically be 30 valid DO samples--for each MMU that was in 
operation for the full year. If dust concentrations on two or more 
of the sampled shifts exceed the standard, then it follows, at a 95-
percent confidence level, that the standard was exceeded on at least 
six shifts over the full year.
---------------------------------------------------------------------------

    When the dust concentration measured for the DO exceeds the 
applicable standard, measurements for at least some of the other miners 
working in the same MMU may also exceed the standard on the same shift, 
though usually by a smaller amount. Furthermore, although the DO 
represents the occupation most likely to receive the highest exposure, 
other miners working in the same MMU may be exposed to even higher 
concentrations than the DO on some shifts. Therefore, in addition to 
the affected DO miners, there is a population of other affected miners 
who are also expected to experience a significant reduction in risk as 
a result of eliminating overexposures on their individual shifts.
    To estimate how many miners other than the DO would be 
substantially affected, MSHA examined the results from all valid dust 
samples collected by MSHA inspectors in underground MMUs during 1999 
(MSHA, Data file: Inspctor.zip). Within each MMU, the inspector 
typically takes one full-shift sample on the DO and, on the same shift, 
four or more additional samples representing other occupations. On 896 
shifts, at a total of 450 distinct MMUs, the DO measurement exceeded 
the applicable standard and there were at least three valid 
measurements for other occupations available for comparison. There was 
an average of 1.2 non-DO

[[Page 42168]]

measurements in excess of the standard on shifts for which the DO 
measurement exceeded the standard.\25\ For non-DO measurements that 
exceeded the standard on the same shift as a DO measurement, the mean 
excess above the standard was approximately (0.8 mg/m\3\).\26\
---------------------------------------------------------------------------

    \25\ With 95-percent confidence, on shifts for which the DO 
measurement exceeds the standard, the mean number of other 
occupational measurements also exceeding the standard is at least 
1.11.
    \26\ With 95-percent confidence, the mean excess is at least 
0.72 mg/m \3\.
---------------------------------------------------------------------------

    Combining these results with the 21-percent rate of excessive 
exposures observed for the DO on individual shifts, it is reasonable to 
infer that, at the MMUs under consideration, an average of 1.2 other 
miners, in addition to the one classified as DO, is overexposed on at 
least 21 percent of all production shifts. Over the course of a working 
year, the reduction in exposure expected for these affected non-
designated occupational (NDO) miners, is 0.17 mg-yr/m\3\ (i.e., 21 
percent of one year, times 0.8 mg/m\3\).
    The expected lifetime for all American males, conditional on their 
having reached 20 years of age, is 73 years (U.S. Census March 1997, 
Table 18; U.S. Census March 1997, Table 119).\27\ On average, the best 
estimate of the lifetime benefit to exposed miners is expressed by the 
reduction in prevalence of disease at age 73. To project the reduction 
in risk of simple CWP and PMF among affected DOs and NDOs, MSHA applied 
its best estimate of dose response to a hypothetical cohort of 
underground coal miners who work on an MMU exhibiting a pattern of 
recurrent overexposure, and who, on average, begin working at age 20, 
retire at age 65, and live to age 73.\28\ Strengths and weaknesses of 
various epidemiological studies were presented in the Health Effects 
section supporting the selection of Attfield and Seixas (1995) as the 
study that provides the best available estimate of material impairment 
with respect to simple CWP and PMF. Two of the distinguishing qualities 
of Attfield and Seixas (1995) are the dose-response relationship over a 
miner's lifetime and the fact that these data best represent the recent 
conditions experienced by miners in the U.S. Using this relationship, 
it is possible to evaluate the impact on risk of both simple CWP and 
PMF expected from bringing respirable coal mine dust concentrations 
down to or below the applicable standard on every shift. This is the 
only contemporary epidemiological study of simple CWP and PMF providing 
such a relationship.
---------------------------------------------------------------------------

    \27\ Since females have a greater life expectancy than males, 
the expected benefits would increase if the proportion of female 
miners were to increase substantially in the future.
    \28\ If a different definition of ``exhibiting a recurrent 
pattern of overexposures'' were used in these analyses, the estimate 
of the reduction in risk and associated benefits would be different. 
For example, if the criterion were that four or more DO bimonthly 
exposure measurements exceeded the applicable standard, we could 
state, with 95% confidence, that the standard was exceeded on at 
least 20 shifts in a year of 384 shifts. Using four as the criterion 
would reduce the population for whom we are estimating benefits, and 
decrease the estimated number of prevented cases by 19%.
---------------------------------------------------------------------------

    To estimate the benefits (i.e., number of cases of simple CWP and 
PMF prevented) of single, full-shift sample and plan verification 
combined, we applied these estimates of risk reduction to the estimated 
sub-populations of affected miners. As of February 12, 1999, there were 
984 producing MMUs;\29\ applying the pattern of recurrent overexposures 
among MMUs as identified in the Quantitative Risk Assessment, 56 
percent, by mine size, we estimate there to be 552 affected MMUs (MSHA 
Table, November 18, 1999; MSHA Table, February 12, 1999). Based on 
MSHA's experience, we would expect one DO and seven NDOs for each shift 
of production at each MMU. Therefore, among underground coal miners 
working on an MMU, we estimate 12.5% to be designated occupational 
miners and 87.5% to be non-designated occupational miners.
---------------------------------------------------------------------------

    \29\ Nine hundred and eighty-four refers to the number of MMUs 
operating on February 12, 1999. The 1,443 number mentioned 
previously refers to all MMUs in operation at any time in 1999.
---------------------------------------------------------------------------

    The benefits that will accrue to coal miners exposed to respirable 
coal mine dust and to mine operators, and ultimately to society at 
large, are substantial and take a number of forms. These proposed rules 
would reduce a significant health risk to underground coal miners, 
reducing the potential for illnesses and premature death and their 
attendant costs to miners, their employers, their families, and 
society.
    The joint promulgation of these rules should realize a positive 
economic impact on the Department of Labor's (DOL's) Black Lung Program 
and relatedly on mine operators. The Black Lung Program compensates 
eligible miners, and their survivors under the Black Lung Benefits Act. 
This program provides monthly payments and medical benefits (diagnostic 
and treatment) to miners who are found to be totally disabled by black 
lung disease, including cases of PMF and simple CWP. In 1986, DOL's 
Employment Standards Administration reported that 12% of approved cases 
of Black Lung Program were identified as cases of PMF based on chest 
radiographs, while sixty-four percent had simple CWP based on chest 
radiographs. For miners who stopped working in coal mines after 1969 
and for whom the DOL can establish that the miner worked for the same 
operator for at least one calendar year, and that miner had at least 
125 working days in that year, that operator is financially responsible 
for the miner's Black Lung benefit payment. If a responsible operator 
cannot be identified for an eligible miner, benefit payments are made 
by the Black Lung Disability Trust Fund. To the extent that these rules 
reduce overexposures to respirable coal mine dust, there should be 
fewer Black Lung Program cases. Therefore, over time, the associated 
financial outlay by responsible operators through either insurance 
premiums or direct payments of Black Lung benefits should be lower than 
would otherwise occur. The financial impact could be substantial see 
discussion in Chapter IV, of the PREA. In 1980, the Black Lung Program 
estimated average lifetime pay-outs for responsible operators for 
married miners of about $248,700 dollars, assuming a 7 percent annual 
rate increase (ESA, 1980). In fiscal year 1999, 443 claims for Black 
Lung Benefits were accepted as new cases; sixty-six percent (293) are 
the financial responsibility of coal mine operators (Peed, 2000).
    Table IX-2 presents the estimated number of cases of simple CWP and 
PMF that would be prevented among the 56 percent of MMUs exhibiting a 
pattern of recurrent overexposures. For all categories of simple CWP 
and PMF combined, we estimate 37 fewer of these cases, among affected 
miners, than would otherwise occur without the promulgation of single, 
full-shift sample and plan verification rules. Eleven of these cases 
would be the most severe form of coal miners pneumoconiosis, PMF, and 
as such this benefit could be interpreted as prevented premature deaths 
due to occupational exposure to respirable coal mine dust. Since simple 
CWP predisposes the development of PMF, it is important that it also be 
prevented (Balaan, et al., 1993).
    As discussed in the Significance of Risk sections, MSHA believes 
this QRA for simple CWP and PMF strikes a reasonable balance based on 
available data. Yet, our estimates likely understate the true impact of 
these rules since our analyses are restricted to a sub-population of 
affected miners, those working at MMUs exhibiting a pattern of 
recurrent overexposures, not the broader population of coal miners who 
will benefit from these rules. Furthermore, to estimate the average

[[Page 42169]]

overexposure which would be prevented, MSHA had to use data collected 
for compliance purposes which may not represent typical environmental 
conditions.
    The degree to which the exposure level of respirable coal mine dust 
on sampling shifts may not be representative of typical exposure levels 
is affected by the following factors:
    (1) There exists a positive relationship between coal production 
and generation of respirable coal mine dust;
    (2) Current sampling procedures permit sampling measurements to be 
taken at the mid-range of the distribution of level of production--
sampling measurements must be taken on shifts with production at least 
60% of the average production during the last 30 days and at least 50% 
of average production for the last valid set of bimonthly samples for 
inspector and operator samples, respectively;
    (3) Miners have reported and MSHA data have demonstrated lower 
levels of production on sampling shifts versus non-sampling shifts 
(MSHA, September 1993);
    (4) On some sampling shifts, miners have reported that more 
engineering controls may be used than on other shifts, thus reducing 
the measured amount of respirable coal mine dust;
    (5) MSHA analyses have demonstrated, even when controlling for 
production, in mines with fewer than 125 employees, on continuous 
mining MMUs, respirable coal mine dust exposures were much higher 
during the unannounced Spot Inspection Program (SIP) sampling shifts 
than on shifts operators sampled--this is consistent with the effect of 
increasing engineering controls on shifts during which bimonthly 
samples are conducted compared to the level of use of engineering 
controls used on shifts for which the operator does not expect sampling 
to be conducted given the same production level (Denk, 1993);
    (6) Across mine size, designated area samples have been found to be 
larger for shifts on which unannounced compliance sampling occurred 
compared to operator sampling shifts-- in one study they differed by at 
least a factor of 40 percent in large mines and 100 percent in the 
smallest mines (ibid. p 211-212); and
    (7) Existing MSHA technical information indicates that some 
reduction in production levels occurs during some sampling periods on 
longwalls (Denk, 1990).
    Therefore, at a bare minimum, over an occupational lifetime (45-
years) for miners who live to age 73 who worked at MMUs exhibiting a 
pattern of recurrent overexposures, we estimate at least 37 fewer cases 
of pneumoconiosis (simple coal workers pneumoconiosis (CWP) and 
progressive massive fibrosis (PMF)) than would otherwise occur without 
the promulgation of these rules.
    Our current quantitative estimate of benefits demonstrates and 
qualitative discussions punctuate that these rules will have a 
significant positive impact on the health of our Nation's coal miners 
when promulgated. Yet, due to the limitations on these data, we believe 
our benefit estimate may understate the number of cases of simple CWP 
and PMF which would be prevented over an occupational lifetime.
    MSHA believes that cases of simple CWP and PMF would also be 
prevented among other types of underground miners, such as roofbolters 
working in designated areas (DA). Based on MSHA experience it is 
reasonable to expect roofbolter DA's pattern of overexposures for 
respirable coal mine dust to be similar to that for miners with the 
highest exposure on an MMU. If so, we would expect 13 additional cases 
of simple CWP and PMF to be prevented. Affected DAs include DAs who 
work at the 56 percent of the MMUs under consideration who are exposed 
to dust concentrations similar to the DO, over a 45-year occupational 
lifetime (MSHA Table, November 18, 1999; MSHA Table, February 12, 
1999).
    Although the effect cannot readily be quantified, to the extent 
that these rules would also reduce the cumulative exposure to 
respirable coal mine dust among some miners working in those MMUs not 
exhibiting overexposures, it is reasonable to expect that we would 
observe an incremental benefit among that sub-population of coal 
miners. Moreover, to the extent that the cumulative dust exposure is 
reduced for miners working in the ``out by'' areas, away from the 
mining face (i.e., MMU) where coal is extracted from the coal seam, 
they too may realize occupational health benefits due to the 
simultaneous promulgation of these proposals. Therefore, our best 
estimate of 37 prevented cases of simple CWP and PMF, combined, among 
all affected miners likely underestimates the true benefit realized by 
the coal mining workforce through the reduction of overexposures to no 
more than the applicable standard on each shift.
    Clearly PMF is associated with premature death. Since simple CWP 
may evolve to PMF, even after occupational exposure has ceased, it has 
the propensity to become a life threatening illness. By reducing the 
total number of simple CWP and PMF cases among affected miners from 259 
to 222, over 45 years, these standards, at a minimum, are projected to 
prevent an average of four cases of simple CWP and PMF for each 5-year 
interval.\30\
---------------------------------------------------------------------------

    \30\ Applying an estimated prevalence rate of 3.0 percent to the 
estimated population of affected miners (8,640) results in an 
estimate of 259 cases of simple CWP and PMF.
---------------------------------------------------------------------------

    For all those reasons previously identified, MSHA believes that its 
estimate of 37 prevented cases of simple CWP and PMF over a 45 year 
working life understates the true number of cases of simple CWP and PMF 
which would be prevented. This belief is further supported by the fact 
that during the past few years, the Black Lung Benefits Program has 
been approving roughly 400 claims each year. These claims come from 
individuals whose exposure for the most part came after the current 
standard of 2.0 was established in 1972. Thus, we believe the 
consistent annual approval by the Black Lung Benefits Program, of 
hundreds of new cases of simple CWP and PMF per year, supports our 
belief that the true lifetime occupational health benefits of the 
proposed rules are higher than we have estimated. Even assuming that 
the number of new claims would decline in future years simply due to 
the continuing decline in the number of coal miners, MSHA expects that 
assuring that future exposures are maintained below the 2.0 exposure 
limit will reduce the number of new cases of simple CWP and PMF by 
considerably more than 1 per year.
    In addition to the prevention of simple CWP and PMF, each of the 
8,640 affected miners at MMUs exhibiting a pattern of recurrent 
overexposures will realize some health benefit by limiting his or her 
cumulative exposure to respirable coal mine dust to no more than the 
applicable standard on each and every shift.
    The expected number of prevented cases of simple CWP and PMF would 
not be realized for some time even after the pattern of overexposures 
has been minimized or eliminated. This is due, in part, to the 
latency--that is, the disease does not develop immediately after 
exposure--of the development of simple CWP and PMF and the pre-existing 
occupational exposure histories of members of the current coal mining 
workforce. Our estimated benefit is based on the estimated number of 
underground coal miners working at the mine face, 17,280. If the size 
of this workforce significantly changed in the future and the projected 
pattern of prevented overexposures remained the same, the number of 
cases of prevented

[[Page 42170]]

simple CWP and PMF would need to be adjusted to account for the change.
    Various data, assumptions and caveats were used to conduct the 
quantitative risk assessment, significance of risk discussion, and 
benefits analyses. Therefore, we request any information which would 
enable us to conduct more accurate analyses of the estimated health 
benefits of the single, full-shift sample rule and plan verification 
rule, both individually, and in combination.

   Table IX-2.--Over a Working Lifetime Among Affected Miners, Estimated Number of Cases of CWP \a\ and PMF \b\
             Prevented Due to the Implementation of Single, Full-Shift Sample and Plan Verification
----------------------------------------------------------------------------------------------------------------
                                           Simple CWP categories   Simple CWP categories            PMF
                                              1, 2, 3 or PMF           2 or 3 or PMF     -----------------------
        Type of Miner          Affected  ------------------------------------------------
                              Miners, n=   Reduction   Prevented   Reduction   Prevented   Reduction   Prevented
                                            in risk    cases, n=    in risk    cases, n=    in risk    Cases, n=
----------------------------------------------\c\---------------------\c\---------------------\c\---------------
Affected Designated                1,080     18/1000        19.4    9.8/1000        10.6    5.1/1000         5.5
 Occupational Miners \d\....
Affected Non-Designated            7,560    2.3/1000        17.4    1.3/1000         9.8    0.7/1000         5.3
 Occupational Miners \e\....
        Total...............       8,640          NA          37          NA          20          NA         11
----------------------------------------------------------------------------------------------------------------
\a\ Simple CWP: Simple coal workers' pneumoconiosis.
\b\ PMF: Progressive massive fibrosis.
\c\ Reduction in risk per 1,000 affected miners, over a 45-year working lifetime.
\d\ Affected Designated Occupation (DO) Miners: Includes all miners who work at the 56-percent of the Mechanized
  Mining Units under consideration and who are exposed to dust concentrations similar to the DO, over a 45-year
  occupational lifetime.
\e\ Affected Non-Designated Occupation (Non-DO) Miners: Includes all underground faceworkers under consideration
  who are not classified as the DO.

B. Regulatory Flexibility Certification and Initial Regulatory 
Flexibility Analysis

    The Regulatory Flexibility Act requires MSHA to conduct an analysis 
of the effects of the proposed plan verification rule on small 
entities. That analysis is summarized here; a copy of the full analysis 
is included in Chapter V of our PREA in support of the proposed single, 
full-shift sample and plan verification rules. We encourage the mining 
community to provide comments on this analysis.
    The Small Business Administration generally considers a small 
entity in the mining industry to be one with 500 or fewer workers. MSHA 
has traditionally defined a small mine to be one with fewer than 20 
workers, and has focused special attention on the problems experienced 
by such mines in implementing safety and health rules. Accordingly, we 
have separately analyzed the impact of the joint notice proposed rule 
both on mines with 500 or fewer workers and on those with fewer than 20 
workers.
    Pursuant to the Regulatory Flexibility Act, MSHA must determine 
whether the costs of the joint notice proposed rule constitute a 
``significant impact on a substantial number of small entities.'' 
Pursuant to the Regulatory Flexibility Act, if an Agency determines 
that a proposed rule would not have such an impact, it must publish a 
``certification'' to that effect. In such a case, no additional 
analysis is required (5 U.S.C. Sec. 605). In evaluating whether 
certification is appropriate, MSHA utilized a ``screening test,'' 
comparing the costs of the proposed plan verification rule to the 
revenues of the affected coal sector. If the estimated costs are less 
than 1 percent of revenues for the affected entities, or they are 
negative (that is, they provide a cost savings), then the rule is 
assumed not to have a significant impact on small mine operators.
    Table IX-3 compares, for small underground coal mines (using both 
MSHA's and SBA's definition), MSHA's estimated total annual compliance 
costs of the proposed plan verification rule to estimated annual 
revenues.
    Table IX-3 shows that under either MSHA's or SBA's definition of a 
small mine, the proposed plan verification rule would provide a net 
cost savings to small underground coal mines. As a result, MSHA is 
certifying that the proposed plan verification rule for underground 
coal mines would not have a ``significant impact on a substantial 
number of small entities,'' and has performed no further analyses.

     Table IX-3.--Estimated Yearly Costs of Proposed Plan Verification Rule Relative to Yearly Revenues for
                                             Underground Coal Mines
                                             [Dollars in thousands]
----------------------------------------------------------------------------------------------------------------
                                                                                    Underground      Costs as
                            Mine size                             Proposed  rule     coal mine     percentage of
                                                                    net costs a     revenues b       revenues
----------------------------------------------------------------------------------------------------------------
 20 employees...................................................        ($930.1)        $249,418          (0.4%)
 500 employees c................................................      ($1,251.9)      $6,883,339        (0.03%)
----------------------------------------------------------------------------------------------------------------
a Estimated yearly costs are composed of ``adjusted'' first year costs that have been annualized plus annual
  costs.
b Data for revenues derived from: U.S. Department of Labor, Mine Safety and Health Administration, Office of
  Standards, Regulations, and Variances, based on 1997 Final MIS data (quarter 1-quarter 4), CM441, cycle 1997/
  184; and U.S. Department of Energy, Energy Information Administration, Annual Energy Review 1998, DOE/EIA-
  0384(98), July 1999, p 203.
c Includes mines with fewer than 20 employees.


[[Page 42171]]

X. Other Statutory Requirements

A. Plain Language

    We (MSHA) wrote appropriate portions of this proposed rule in the 
more personal style advocated by the President's Memorandum on ``plain 
language.'' ``Plain language'' encourages the use of personal pronouns 
(we and you); sentences in the active voice; a greater use of headings, 
lists, and questions, as well as charts, figures, and tables.
    In this proposed rule, ``you'' refers to production-operators and 
independent contractors because they have the primary responsibility 
for compliance with MSHA regulations. In addition, we recognize and 
appreciate the value of comments, ideas, and suggestions from labor 
organizations, industry associations, and other parties who have an 
interest in health and safety training for miners.
    We would appreciate comments and suggestions from all parties on 
this proposed rule and on our use of ``plain language.'' How could we 
improve the clarity of this style?

B. Unfunded Mandates Reform Act of 1995

    For purposes of the Unfunded Mandates Reform Act of 1995, this rule 
does not include any Federal mandate that may result in increased 
expenditures by State, local, and tribal governments, or increased 
expenditures by the private sector of more than $100 million.

C. Paperwork Reduction Act of 1995

    The proposed plan verification rule contains information 
collections which are subject to review by the Office of Management and 
Budget (OMB) under the Paperwork Reduction Act of 1995 (PRA95). The 
proposed rule has first year burden hours (those that occur only in the 
first year) and, annual burden hours which occur in the first year and 
every year thereafter.
    How some types of burden hours and costs were handled requires 
explanation. In a few cases, the proposed plan verification rule 
imposes burden hours and costs that would be the same every year, 
beginning with the first year that the rule takes effect. These are 
``annual'' burden hours and costs, as traditionally defined.
    In most cases, however, the proposed plan verification rule imposes 
burden hours and costs which would be the same each year starting with 
the second year the proposed rule is in effect, but whose first year 
burden hours and costs would be different. MSHA transformed these first 
year burden hours and costs and annual burden hours and costs starting 
in Year 2 into adjusted first year burden hours and costs (first year 
burden hours and costs minus an amount equal to annual burden hours and 
costs starting with Year 2 after the rule takes effect) and true annual 
burden hours and costs starting in Year 1 after the rule takes 
effect.\31\
---------------------------------------------------------------------------

    \31\ A hypothetical example might help to explain this 
procedure. Suppose that compliance costs are $2,000 the first year 
and $400 each year thereafter. The adjustment procedure simply 
splits first year compliance costs into two parts: (1) $400, for the 
first year of annual costs; and (2) the residual $1,600. 
Consequently, adjusted first year costs would be $1,600 and annual 
costs (starting in year 1) would be $400.
---------------------------------------------------------------------------

First Year Burden Hours

    In the first year the plan verification rule is in effect, there 
would be a total net burden hour savings, for underground coal mine 
operators, of 44,750, which is composed of 7,912 first year burden 
hours (from Table X-1) and 52,662 annual burden hour savings (from 
Table X-2). The 44,750 net burden hour savings have associated cost 
savings of $847,236, which is composed of $360,820 of adjusted first 
year costs (from Table X-1) and $1,208,056 of annual cost savings (from 
Table X-2).

Annual Burden Hours in Second Year and Every Year Thereafter

    There would be a total net annual burden hour savings, for 
underground coal mine operators, in the second year the proposed plan 
verification rule is in effect and every year thereafter of 52,662, 
which has associated cost savings of approximately $1.21 million 
annually (from Table X-2). These net burden hours and costs include 
annual burden hour and cost savings due to: reduced mine operator 
citations based on MSHA inspectors' single, full-shift sample results 
and the elimination of associated operator abatement sampling; reduced 
mine operator citations issued based on bi-monthly sampling results and 
the elimination of associated operator abatement sampling; and savings 
from operators no longer having to perform bi-monthly operator 
sampling.

[[Page 42172]]



                                 Table X-1.--Summary of PV Proposed Rule First Year Paperwork Burden Hours and Related Costs That Occur Only in the First Year*
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                     20 emp.                   20 emp. 500                  >500 emp.                                Total
                                     -----------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Adjusted                               Adjusted                               Adjusted                               adjusted
               Detail                   Adjusted     Adjusted    first year    Adjusted     Adjusted    first year    Adusted      Adjusted    first year    Adjusted     Adjusted    first year
                                       first year   first year     costs      first year   first year     costs      first year   first year     costs      first year   first year     costs
                                         hours        costs      annualized     hours        costs      annualized     hours        costs      annualized     hours        costs      annualized
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     UNDERGROUND COAL MINES
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
PV Rule:
    Increase........................        1,359      $61,059       $4,274        6,140     $280,581      $20,372          398      $18,425       $1,399        7,897     $360,065      $26,045
    Reduced Inspector Citations \a\.            3         $151          $11            6         $302          $21            0           $0           $0            9         $453          $32
    Reducted Operator citations \b\.            3         $151          $11            3         $151          $11            0           $0            0            6         $302          $22
    Elimination of Bi-Mo. Sampling..            0           $0           $0            0           $0           $0            0           $0           $0            0           $0           $0
Net PV Rule.........................        1,365      $61,361       $4,296        6,149     $281,034      $20,404          398      $18,425       $1,399        7,912     $360,820     $26,099
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Source: Preliminary Regulatory Economic Analysis Tables VII-32, VII-43, and VII-53.
\a\ Related to reduced citations issued based on inspector sample results due to better mine ventilation plans arising from the PV rule.
\b\ Related to reduced citations issued based on operator sample results due to better mine ventilation plans arising from the PV rule.


[[Page 42173]]


             Table X-2.--Summary of Annual Paperwork Burden Hours and Related Costs That Occur in the First Year and Every Year Thereafter *
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                        20 emp.           20 emp. 500 emp.                    Total
                                              --------------------------        thn-eq>500        ------------------------------------------------------
                    Detail                                              --------------------------
                                                  Annual       Annual       Annual       Annual       Annual       Annual       Annual     Annual costs
                                                  hours        costs        hours        costs        hours        costs        hours
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 UNDERGROUND COAL MINES
--------------------------------------------------------------------------------------------------------------------------------------------------------
 PV Rule:
    Increase............................................................................................................................................
    Reduced Inspector Citations \a\.....................................................................................................................
    Reduced Operator Citations \b\......................................................................................................................
    Elimination of Bi-Mo. Sampling......................................................................................................................
Net PV Rule.............................................................................................................................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
\*\ Source: Preliminary Regulatory Economic Analysis Tables VII-7, VII-33, VII-43, VII-53, and VII-57.
\a\ Reduction related to: (1) Reduced citations issued based on inspector sample results due to better mine ventilation plans arising from the PV rule
  and (2) reduced abatement sampling and associated costs due to the elimination of bi-monthly operator sampling.
\b\ Reduction related to: (1) Reduced citations issued based on operator sample results due to better mine ventilation plans arising from the PV rule
  and (2) reduced abatement sampling and associated costs due to the elimination of bi-monthly operator sampling.

    We invite public comments and are particularly interested in 
comments which:
    1. Evaluate whether the proposed collection of information 
(presented here and in the PREA for the proposed single, full-shift 
sample and plan verification rules) is necessary for the proper 
performance of the functions of MSHA, including whether the information 
will have practical utility;
    2. Evaluate the accuracy of our estimate of the burden of the 
proposed collection of information, including the validity of the 
methodology and assumptions used;
    3. Enhance the quality, utility, and clarity of the information to 
be collected; and
    4. Minimize the burden of the collection of information on 
respondents, including through the use of appropriate automated, 
electronic, mechanical, or other technological collection techniques or 
other forms of information technology, e.g., permitting electronic 
submissions of responses.
    We have submitted a copy of this proposed rule to OMB for its 
review and approval of these information collections. Interested 
persons are requested to send comments regarding this information 
collection, including suggestions for reducing this burden, to the 
Office of Information and Regulatory Affairs, OMB New Executive Office 
Building, 725 17th St., NW, Rm. 10235, Washington, DC 20503, Attn: Desk 
Officer for MSHA. Submit written comments on the information collection 
not later than September 5, 2000.
    Our paperwork submission summarized above is explained in detail in 
the PREA. The PREA includes the estimated costs and assumptions for 
each proposed paperwork requirement related to this proposed rule. A 
copy of the PREA is available from us. These paperwork requirements 
have been submitted to the Office of Management and Budget for review 
under section 3504(h) of the Paperwork Reduction Act of 1995. 
Respondents are not required to respond to any collection of 
information unless it displays a current valid OMB control number.

D. National Environmental Protection Act

    The National Environmental Policy Act (NEPA) of 1969 requires each 
Federal agency to consider the environmental effects of proposed 
actions and to prepare an Environmental Impact Statement on major 
actions significantly affecting the quality of the human environment. 
We have reviewed the proposed standard in accordance with the 
requirements of the NEPA (42 U.S.C. 4321 et seq.), the regulation of 
the Council on Environmental Quality (40 CFR part 1500), and the 
Department of Labor's NEPA procedures (29 CFR part 11). As a result of 
this review, we have preliminarily determined that this proposed 
standard will have no significant environmental impact.
    Commenters are encouraged to submit their comments on this 
determination.

E. Executive Order 12630 (Governmental Actions and Interference with 
Constitutionally Protected Property Rights)

    This proposed rule is not subject to Executive Order 12630, 
Governmental Actions and Interference with Constitutionally Protected 
Property Rights, because it does not involve implementation of a policy 
with takings implications.

F. Executive Order 12988 (Civil Justice)

    The Agency has reviewed Executive Order 12988, Civil Justice 
Reform, and determined that this rulemaking will not unduly burden the 
Federal court system. The regulation has been written so as to provide 
a clear legal standard for affected conduct, and has been reviewed 
carefully to eliminate drafting errors and ambiguities.

G. Executive Order 13045: Protection of Children from Environmental 
Health Risks and Safety Risks

    In accordance with Executive Order 13045, protection of children 
from environmental health risks and safety risks, we have evaluated the 
environmental health or safety effects of the proposed rule on 
children. The Agency has determined that this proposal would not have 
an adverse impact on children.

H. Executive Order 13084 (Consultation and Coordination With Indian 
Tribal Governments)

    We certify that this proposed rule does not impose substantial 
direct compliance costs on Indian tribal governments.

I. Executive Order 13132 (Federalism)

    We have reviewed this rule in accordance with Executive Order 13132 
regarding federalism, and have determined that it does not have 
``federalism implications.'' The rule does not ``have substantial 
direct effects on the States, on the relationship between the national 
government and the States, or on the distribution of

[[Page 42174]]

power and responsibilities among the various levels of government.''

XI. Public Hearings

    MSHA plans to hold public hearings on the proposed rule. The 
hearings will be held in Prestonsburg, Kentucky (Jenny Wiley, State 
Resort Park); Morgantown, West Virginia; and Salt Lake City, Utah. The 
hearing dates, times, and specific locations will be announced by a 
separate document in the Federal Register. The hearings will be held 
under Section 101 of the Federal Mine Safety and Health Act of 1977.

Appendix A--Derivation of the Critical Values

    All measurements of respirable dust concentration are subject to 
potential sampling and analytical errors. Because of such errors, a 
measurement may fall slightly below the verification limit even when 
the true concentration of respirable coal mine dust or crystalline 
silica does not. Therefore, to ensure that the verification limits 
have actually been met, it is necessary to provide for a margin of 
error in each measurement. The critical values provide this margin 
of error. When valid measurements do not exceed the appropriate 
critical values, we can be confident that the verification limits 
have not been exceeded at the sampled locations.
    To explain how the verification limits were derived, it is 
helpful to define some symbolic notation. Let X represent a 
measurement, and let  represent the true value of whatever 
quantity is being measured--i.e., the full shift average 
concentration, at a specific sampling location, of either respirable 
coal mine dust or respirable crystalline silica dust. The difference 
between X and  is the measurement error and is denoted by 
. X =  + .
    In accordance with standard statistical and industrial hygiene 
practice,  (but not ) is assumed to be normally 
distributed. Since the approved sampling and analytical methods for 
measuring concentrations of respirable coal mine dust and respirable 
silica dust are both statistically unbiased,  has a mean 
value of zero and a degree of variability represented by its 
standard deviation, denoted by . The ratio of 
 to  is called the measurement 
coefficient of variation (CV) due to sampling and analytical 
errors.\1\ The CV relates entirely to variability due to measurement 
errors and not at all to variability in actual dust concentrations.
---------------------------------------------------------------------------

    \1\ In some publications, this ratio is called the relative 
standard deviation (RSD). It is sometimes also denoted by 
CVtotal, where ``total'' refers to all sources of 
potential sampling and analytical error but does not cover 
variability in  itself.
---------------------------------------------------------------------------

    For respirable coal mine dust, the value of CV used in 
calculating critical values was chosen to be consistent with the 
value proposed at  = 2.0 mg/m\3\ in the Coal Mine 
Respirable Dust Standard Noncompliance Determinations Notice, (63 FR 
5700, February 3, 1998):
[GRAPHIC] [TIFF OMITTED] TP43AD00.000

The 7-percent term in this formula accounts for uncertainty due to 
potential weighing error, and the two 5-percent terms account for 
differences between individual cyclones and for variability in the 
exact volume of air pumped through the filter during a 480-minute 
shift.
    For respirable silica dust, the value of CV used in calculating 
critical values is:
[GRAPHIC] [TIFF OMITTED] TP43AD00.001

The 5.3-percent term in this formula accounts for imprecision in the 
Infrared (Infrared Spectrophotometer or IR) measurement of 
crystalline silica mass deposited on the filter, the 4.2-percent 
term represents variability in air volume, and the final 5.6-percent 
term accounts for uncertainty due to variability between individual 
cyclones, given the size distribution of crystalline silica dust 
encountered in mining environments (Bartley, November 1999).
    Each critical value (c) was calculated to provide a confidence 
level of at least 95 percent that the ventilation plan was effective 
in preventing dust concentrations from exceeding the verification 
limits. Using a confidence coefficient of 1.645, based on the 
standard normal probability distribution, knowledge of the CV makes 
it possible to calculate a 1-tailed, 95-percent upper confidence 
limit (UCL) for , given a single measurement X. The UCL is 
X(1 + 1.645CV). When X  c, the UCL 
for  is less than or equal to the verification limit. When 
X > c, the UCL for  exceeds the verification limit.
    For example, suppose X = 1.71 mg/m\3\ respirable dust. Then the 
UCL for  would be 1.71(1 + (10% of 1.645)) = 1.99 
mg/m\3\, which is less than the verification limit for respirable 
coal mine dust. If, however, X = 1.72 mg/m\3\, then the UCL for 
 would be 1.721.1645 mg/m\3\, which slightly 
exceeds the verification limit. Similarly, for respirable 
crystalline silica dust, the UCL for  is 87(1 + 
(9% of 1.645)) = 99.9 g/m\3\ when X = 87 g/m\3\ 
and slightly above the verification limit of 100 g/m\3\ 
when X = 88 g/m\3\.
    If more than one measurement is available, then the confidence 
coefficient changes to reflect multiplication of the tail 
probabilities for independent measurement errors. When n 
measurements are available, the objective is to calculate a critical 
value (c) such that if each of the n measurements is  c, 
then the 1-tailed 95-percent UCL for  is  the 
verification limit. Since the product of the n individual tail 
probabilities must equal 0.05, the appropriate 1-tail probability 
for each measurement individually is the n\th\ root of 0.05.
    For example, if n = 3, then the appropriate 1-tail probability 
for each measurement is the cube root of 0.05, or 0.3684. The 
standard normal confidence coefficient corresponding to this tail 
probability is 0.336. Therefore, when all three measurements have 
the same value (X), the UCL is X(1+0.336CV). 
Substituting the appropriate CV estimate, the UCL is 
X1.0336 for coal mine dust or X1.0302 for 
crystalline silica. Consequently, to obtain the critical value, the 
verification limit is first divided by 1.0336 (coal mine dust) or 
1.0302 (crystalline silica dust) and then truncated to the desired 
number of decimal digits. This yields 1.93 mg/m\3\ for coal mine 
dust and 97 g/m\3\ for respirable crystalline silica dust.
    The confidence coefficients used to establish critical values by 
this method are as follows:

n--Confidence Coefficient 

1    1.645
2    0.760
3    0.336
4    0.068
For n > 4, the confidence coefficient is less than 0.068.

    It should be noted that although the critical value calculated 
for n  4 is slightly below the verification limit for 
both types of dust, for simplicity it was set equal to the 
verification limit as a close approximation.

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XII. Regulatory Text

List of Subjects

30 CFR part 70

    Coal, Mine safety and health, Underground coal mines, Respirable 
dust.

30 CFR part 75

    Coal, Mine safety and health, Underground coal mines, Ventilation.

30 CFR part 90

    Coal, Mine safety and health.

    Dated: June 20, 2000.
J. Davitt McAteer,
Assistant Secretary for Mine Safety and Health.
    Accordingly, it is proposed to amend Chapter I of Title 30 of the 
Code of Federal Regulations as follows:

PART 70--MANDATORY HEALTH STANDARDS--UNDERGROUND COAL MINES

    1. The authority citation for part 70 continues to read as follows:

    Authority: 30 U.S.C. 811, 813(h), 957 and 961, unless otherwise 
noted.

    2. Section 70.2 is revised to read as follows:
Subpart A--General
Sec.
70.2   Definitions.

Subpart A--General


Sec. 70.2  Definitions.

    (a) Act means the Federal Mine Safety and Health Act of 1977, 
Public Law 91-173, as amended by Public Law 95-164, 30 U.S.C. 801 et. 
seq.
    (b) Active workings means any place in a coal mine where miners are 
normally required to work or travel.
    (c) Concentration means an 8-hour MRE equivalent measure of the 
amount of respirable dust per unit volume of air. The concentration of 
respirable dust is determined in two steps. First, divide the weight of 
dust in milligrams collected on the filter of an approved sampling 
device by 480 minutes times the sampler flow rate. Second, multiply 
that concentration by a constant factor prescribed by the Secretary for 
the approved sampling device used. The product is the equivalent 
concentration as measured with an MRE instrument.
    (d) Critical value means the highest full shift dust concentration 
measurement that MSHA will accept in approving a mine ventilation plan 
or interim plan.
    (e) Designated area (DA) means an area of a mine identified by the 
operator under Sec. 75.371(t) of this title and approved by the 
District Manager, or identified by the Secretary. Each DA will be 
identified by a four-digit identification number assigned by MSHA.
    (f) Designated occupation (DO) means the occupation or work 
location on a mechanized mining unit that has been determined by 
results of respirable dust samples to have the greatest respirable dust 
concentration.
    (g) District Manager means the manager of the Coal Mine Safety and 
Health District in which the mine is located.
    (h) Dust control parameters means the engineering or environmental 
controls, maintenance procedures, and any other requirements specified 
in each ventilation plan that are being used on the mechanized mining 
unit and throughout the mine to control the level of respirable coal 
mine dust and respirable quartz dust in the work environment.
    (i) Engineering or environmental controls means any method to 
control the level of respirable coal mine dust and quartz dust in the 
work environment by either reducing dust generation or by suppressing, 
diluting, capturing or diverting the dust being generated during the 
mining process. It does not include powered, air-purifying respirators 
(PAPRs) or any other type of personal protection equipment.
    (j) Full shift means an entire work shift including travel time but 
excluding, for purposes of bimonthly sampling only, any time in excess 
of 480 minutes.

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    (k) Interim ventilation plan means a ventilation plan for a 
longwall operation under which operators are allowed to use PAPRs or 
verifiable administrative controls.
    (l) Longwall face means a working place in a coal mine where coal 
is extracted from the exposed face or seam using the longwall method of 
mining.
    (m) Longwall mining section means the area of the coal mine 
employing longwall mining, from the loading point of the section up to 
and including the longwall face. The loading point is also included.
    (n) Material produced means coal and/or any other substance 
extracted by a mechanized mining unit during any production shift.
    (o) Mechanized mining unit (MMU) means a unit of mining equipment 
including hand loading equipment used for the production of material; 
or a specialized unit which utilizes mining equipment other than 
specified in Sec. 70.206 for the production of material. MSHA assigns 
each MMU a four digit identification number. The MMU retains the 
identification number regardless of where the unit relocates within the 
mine. When two sets of mining equipment are provided in a series of 
working places and only one production crew is employed at any given 
time on either set of mining equipment, the two sets of equipment are 
identified as a single MMU. When two or more MMUs are simultaneously 
engaged in the production of material within the same working section, 
each such MMU is identified separately.
    (p) MRE means the Mining Research Establishment of the National 
Coal Board, London, England.
    (q) MRE instrument means the gravimetric dust sampler with a four 
channel horizontal elutriator developed by the Mining Research 
Establishment of the National Coal Board, London, England.
    (r) MSHA means the Mine Safety and Health Administration of the 
Department of Labor.
    (s) Powered, air-purifying respirator (PAPR) means a type of loose-
fitting helmet respirator with a visor that uses a blower to force the 
ambient air through air-purifying elements to deliver filtered air into 
the miner's breathing area.
    (t) Production shift means:
    (1) With regard to a mechanized mining unit, a shift during which 
material is produced, or
    (2) With regard to a designated area of a mine, a shift during 
which material is produced and routine day-to-day activities are 
occurring in the designated area.
    (u) Provisional ventilation plan means a ventilation plan which has 
been approved by the District Manager pending verification by MSHA of 
the effectiveness of the plan's dust control parameters.
    (v) Quartz means crystalline silicon dioxide (SiO2) as 
measured by MSHA's Analytical Method P-7: Infrared Determination of 
Quartz in Respirable Coal Mine Dust.
    (w) Respirable dust means dust collected with a sampling device 
approved by the Secretary and the Secretary of Health and Human 
Services in accordance with part 74 (Coal Mine Dust Personal Sampler 
Units) of this title. Sampling device approvals issued by the Secretary 
of the Interior and Secretary of Health, Education, and Welfare are 
continued in effect.
    (x) Secretary means the Secretary of Labor or delegate.
    (y) Verifiable administrative control means any work practice that 
can significantly reduce daily exposure to respirable dust hazards by 
altering the way in which work is performed and which:
    (1) Can be reviewed to confirm its proper implementation,
    (2) Is clearly understood by miners, and
    (3) Can be applied consistently over time.
    (z) Verification limits means 2.0 mg/m\3\ of respirable coal mine 
dust and 100 g/m\3\ of respirable quartz dust (MRE-equivalent 
concentrations) measured over a full shift.
    (aa) Verification production level (VPL) means the tenth highest 
production level recorded in the most recent thirty production shifts.
    (bb) Verification sample means a valid sample taken on a full shift 
during which the amount of material produced is at or above the VPL and 
using only the engineering or environmental controls and other measures 
included in the ventilation plan, at levels not exceeding 115% of the 
quantities specified in the plan.
    3. Subpart B is revised to read as follows:

Subpart B--Dust Standards

70.100  What are the respirable dust standards when quartz is not 
present?
70.101  What is the respirable dust standard when quartz is present?

Subpart B--Dust Standards

    Authority: 30 U.S.C. 811 and 813(h).


Sec. 70.100  What are the respirable dust standards when quartz is not 
present?

    When quartz is not present:
    (a) Each operator shall continuously maintain the average 
concentration of respirable dust in the mine atmosphere during each 
shift to which each miner in the active workings of each mine is 
exposed at or below 2.0 milligrams of respirable dust per cubic meter 
of air as measured with an approved sampling device and in terms of an 
equivalent concentration determined in accordance with Sec. 70.2(c).
    (b) Each operator shall continuously maintain the average 
concentration of respirable dust within 200 feet outby the working 
faces of each section in the intake airways at or below 1.0 milligrams 
of respirable dust per cubic meter of air as measured with an approved 
sampling device and in terms of an equivalent concentration determined 
in accordance with Sec. 70.2(c).


Sec. 70.101  What is the respirable dust standard when quartz is 
present?

    When the respirable dust in the mine atmosphere of the active 
workings contains more than 5 percent quartz as determined by samples 
taken by the Secretary, the operator shall continuously maintain the 
average concentration of respirable dust in the mine atmosphere during 
each shift to which each miner in the active workings is exposed at or 
below a concentration of respirable dust, expressed in milligrams per 
cubic meter of air as measured with an approved sampling device and in 
terms of an equivalent concentration determined in accordance with 
Sec. 70.2(c), computed by dividing the percent of quartz into the 
number 10.

    Example: The respirable dust associated with a mechanized mining 
unit or a designated area in a mine contains quartz in the amount of 
20%. Therefore, the average concentration of respirable dust in the 
mine atmosphere associated with that mechanized mining unit or 
designated area shall be continuously maintained at or below 0.5 
milligrams of respirable dust per cubic meter of air (10/20=0.5 mg/m\3\ 
).

    4. Subpart C is revised to read as follows:

[[Page 42179]]

Subpart C--Verification of Underground Coal Mine Ventilation Plan 
Effectiveness; Use of Approved Powered, Air-Purifying Respirators; 
Use of Verifiable Administrative Controls; Actions Necessary When 
in Violation of Respirable Dust Standard; and Status Change Reports

Verification of Underground Coal Mine Ventilation Plan Effectiveness
70.201  Who must have a verified ventilation plan?
70.202  What is a verified ventilation plan?
70.203  What will trigger the plan verification process?
70.204  When will MSHA conduct verification sampling?
70.205  What must I (the operator) do to comply with this standard?
70.206  Who will MSHA sample and where will MSHA place the sampling 
device(s) when conducting verification sampling?
70.207  How many shifts will MSHA sample to verify my ventilation 
plan?
70.208  What if 30 shifts of production data are not available to 
establish the verification production level (VPL)?
70.209  When will MSHA approve my ventilation plan?
70.210  What must I (the operator) do if a verification sample 
exceeds either verification limit?
70.211  What if verification samples continue to exceed either 
verification limit even though I (the operator) believe all feasible 
engineer and environmental controls are in place?

Use of Approved Powered, Air-Purifying Respirators

70.212  For my longwall operation, what must I (the operator) do in 
order to use approved PAPRs to supplement engineering or 
environmental controls?
70.213  For my longwall operation, when will MSHA approve my interim 
ventilation plan incorporating a PAPR respiratory protection 
program?
70.214  For my longwall operation, under what circumstances may I 
(the operator) continue to use PAPRs to supplement engineering or 
environmental controls?
70.215  What if an MSHA DO sample exceeds the applicable dust 
standard, or an MSHA sample for a miner required to wear a PAPR 
exceeds twice the applicable dust standard?

Use of Verifiable Administrative Controls

70.216  For my longwall operation, what must I (the operator) do in 
order to use verifiable administrative controls to supplement 
engineering or environmental controls?
70.217  For my longwall operation, when will MSHA approve my interim 
ventilation plan incorporating verifiable administrative controls?
70.218  For my longwall operation with an approved interim 
ventilation plan, what must I (the operator) do if an MSHA sample 
exceeds the applicable dust standard?

Actions Necessary When in Violation of Respirable Dust Standards

70.219  What must I (the operator) do if I am cited for exceeding 
the applicable dust standard?

Information to Be Posted on the Mine Bulletin Board

70.220  What information must I (the operator) post on the mine 
bulletin board?

Status Change Reports

70.221  What action must I (the operator) take if the operational 
status of my mine, MMU, or DA changes?

Subpart C--Verification of Underground Coal Mine Ventilation Plan 
Effectiveness; Use of Approved Powered, Air-Purifying Respirators; 
Use of Verifiable Administrative Controls; Actions Necessary When 
in Violation of Respirable Dust Standard; and Status Change Reports

    Authority: 30 U.S.C. 811, 813(h), and 957.

Verification of Underground Coal Mine Ventilation Plan 
Effectiveness


Sec. 70.201  Who must have a verified ventilation plan?

    All underground coal mine operators must have a verified 
ventilation plan.


Sec. 70.202  What is a verified ventilation plan?

    A verified ventilation plan is a plan that has been demonstrated as 
effective, at a high level of confidence, in maintaining the 
concentration of respirable coal mine dust and quartz dust in each MMU 
at or below 2.0 mg/m\3\ and 100 g/m\3\, respectively. This 
demonstration is based on MSHA verification samples.


Sec. 70.203  What will trigger the plan verification process?

    MSHA will initiate the plan verification process when:
    (a) You submit a new ventilation plan under Sec. 75.370 or you 
amend a previously approved ventilation plan under Sec. 75.371(f); or
    (b) The District Manager requires you to change the ventilation 
plan after determining that your dust control parameters no longer 
effectively control the concentration of respirable dust in the working 
environment of an MMU under the current mining conditions; or
    (c) You propose revisions to a previously verified ventilation plan 
and the District Manager determines that the proposed revisions may 
cause the plan to be inadequate.


Sec. 70.204  When will MSHA conduct verification sampling?

    The District Manager will notify you of the schedule for 
verification sampling after granting provisional approval of your 
ventilation plan. Before you receive provisional approval, however, you 
may be required to change your plan if the District Manager determines 
that your dust control parameters are inadequate or unsuitable for the 
current mining conditions.


Sec. 70.205  What must I (the operator) do to comply with this 
standard?

    To comply with this standard, at the time the District Manager 
notifies you that MSHA will conduct verification sampling you must:
    (a) Set your operating conditions so as to mine at or above the VPL 
and use only the dust control parameters and other measures listed in 
your plan on the date scheduled for verification sampling;
    (b) For each MMU to be sampled, make available records of the 
amount of material produced each shift during the previous six-month 
period as prescribed in Sec. 75.370(h);
    (c) Provide the additional information described under 
Sec. 75.371(f); and
    (d) Notify the District Manager if you cannot meet the conditions 
described in paragraph (a) on the scheduled date.


Sec. 70.206  Who will MSHA sample and where will MSHA place the 
sampling device(s) when conducting verification sampling?

    (a) MSHA will sample the environment of:
    (1) The designated occupation (DO); roofbolter operators; longwall 
jack setters; and
    (2) Any other occupation designated by the District Manager.
    (b) Unless otherwise directed by the District Manager, MSHA will 
take DO samples by placing the sampling device(s) in the following 
locations:
    (1) Conventional section using cutting machine--on the cutting 
machine operator or on the cutting machine within 36 inches inby the 
normal working position;
    (2) Conventional section shooting off the solid--on the loading 
machine operator or on the loading machine within 36 inches inby the 
normal working position;
    (3) Continuous mining section other than auger-type--on the 
continuous mining machine operator or on the continuous mining machine 
within 36 inches inby the normal working position;
    (4) Continuous mining machine; auger-type--on the jacksetter who 
works nearest the working face on the return air side of the continuous 
mining machine or at a location that represents the maximum 
concentration of dust to which the miner is exposed;

[[Page 42180]]

    (5) Scoop section using cutting machine--on the cutting machine 
operator or on the cutting machine within 36 inches inby the normal 
working position;
    (6) Scoop section shooting off the solid--on the coal drill 
operator or on the coal drill within 36 inches inby the normal working 
position;
    (7) Longwall section--on the miner who works nearest the return air 
side of the longwall working face or along the working face on the 
return side within 48 inches of the corner;
    (8) Hand loading section with a cutting machine--on the cutting 
machine operator or on the cutting machine within 36 inches inby the 
normal working position;
    (9) Hand loading section shooting off the solid--on the hand loader 
exposed to the greatest dust concentration or at a location that 
represents the maximum concentration of dust to which the miner is 
exposed; and
    (10) Anthracite mine sections--on the hand loader exposed to the 
greatest dust concentration or at a location that represents the 
maximum concentration of dust to which the miner is exposed.


Sec. 70.207  How many shifts will MSHA sample to verify my ventilation 
plan?

    MSHA can approve your ventilation plan based on only one shift of 
sampling, provided all the samples taken on that shift meet the 
criteria for a verification sample and none of them exceed the critical 
values for a single shift specified in Secs. 70.209 and 70.213. We will 
sample additional shifts if one verification sample exceeds the 
specified critical values, or if any of the samples taken do not meet 
the criteria for a verification sample.


Sec. 70.208  What if 30 shifts of production data are not available to 
establish the verification production level (VPL)?

    If you do not have 30 shifts of production data to establish a VPL, 
the VPL will be the minimum production level attained on a shift that 
was sampled to verify the plan's effectiveness. This production level 
must be incorporated into the ventilation plan that is ultimately 
approved by the District Manager.


Sec. 70.209  When will MSHA approve my ventilation plan?

    MSHA will approve your ventilation plan when:
    (a) None of the verification samples exceed the following critical 
values for respirable coal mine dust and quartz dust:
    (1) For respirable coal mine dust, the critical value is:
    (i) 1.71 mg/m\3\ if samples are collected for only one shift;
    (ii) 1.85 mg/m\3\ if samples are collected for two shifts;
    (iii)1.93 mg/m\3\ if samples are collected for three shifts; and
    (iv) 2.0 mg/m\3\ if samples are collected for four or more shifts.
    (2) For respirable quartz dust, the critical value is:
    (i) 87 ``g/m\3\ if samples are collected for only one 
shift;
    (ii) 93 ``g/m\3\ if samples are collected for two shifts;
    (iii) 97 ``g/m\3\ if samples are collected for three 
shifts; and
    (iv) 100 ``g/m\3\ if samples are collected for four or 
more shifts.
    (b) You adjust your plan, if necessary, to include all the dust 
control parameters that were in effect during verification sampling.


Sec. 70.210  What must I (the operator) do if a verification sample 
exceeds either verification limit?

    If a verification sample exceeds either verification limit, you 
must:
    (a) Immediately take corrective action to lower the concentration 
of respirable dust in the work environment of the affected occupation 
or location to a level no greater than the applicable verification 
limit;
    (b) Make approved respiratory equipment available to affected 
miners following the procedures in Sec. 70.300; and
    (c) Within 5 days of receiving results of verification sampling, 
submit changes in your dust control parameters and any other corrective 
actions you implemented to the District Manager for review. The 
District Manager will notify you if your ventilation plan is 
provisionally approved under Sec. 70.210 (c).
    (1) If your ventilation plan is provisionally approved, the 
District Manager will notify you when MSHA will start verification 
sampling over again, or continue verification sampling.
    (2) If your ventilation plan is not provisionally approved, the 
District Manager will require you to make additional changes in your 
plan parameters. Once you have made all required changes to your plan 
parameters, you will receive provisional approval of your ventilation 
plan. Then, the District Manager will notify you when MSHA will start 
verification sampling over again, or continue verification sampling 
from the point at which it stopped.


Sec. 70.211  What if verification samples continue to exceed either 
verification limit even though I (the operator) believe all feasible 
engineering and environmental controls are in place?

    If verification samples continue to exceed the verification limit 
and you believe all feasible engineering and environmental controls are 
in place, then:
    (a) If the ventilation plan being verified is for an MMU that uses 
a mining system other than longwall mining, MSHA may suggest additional 
controls for you to implement.
    (b) If the MMU employs a longwall mining system, MSHA may suggest 
additional controls for you to implement; and, you may request in 
writing that the Administrator for Coal Mine Safety and Health 
determine whether or not you are using all feasible engineering or 
environmental controls to reduce concentrations of respirable dust to 
as low a level as possible; and
    (c) If MSHA determines that you are using all feasible engineering 
or environmental on your longwall, based on its assessment of the 
suitability of available control measures to your particular MMU, MSHA 
will notify you that you may use either powered, air-purifying 
respirators (PAPRs) approved under 42 CFR 84, or verifiable 
administrative controls on an interim basis to supplement the 
engineering or environmental controls you have implemented to achieve 
compliance, until additional feasible engineering or environmental 
controls become available. If you use these supplements, the DO would 
be changed from the 060 to the 044 occupation.

Use of Approved Powered, Air-Purifying Respirators


Sec. 70.212  For my longwall operation, what must I (the operator) do 
in order to use approved PAPRs to supplement engineering or 
environmental controls?

    In order to use PAPRs to supplement engineering or environmental 
controls, you must:
    (a) Submit a revised ventilation plan to the District Manager 
within 5 days of receiving notification allowing you to supplement the 
engineering or environmental controls on your longwall for compliance 
purposes. Your plan must include feasible engineering or environmental 
controls capable of maintaining concentrations of respirable dust in 
the environment of:
    (1) The DO (Occ 044--longwall operator or the occupation selected 
by the District Manager) at or below the verification limits; and
    (2) Any miner working downwind of the DO, who is required to wear a 
PAPR,

[[Page 42181]]

at or below two times the verification limits.
    (b) Incorporate in your plan a respiratory protection program for 
the use of PAPRs following the procedures specified in Sec. 72.710. 
MSHA's District Manager may require you to make modifications to your 
respiratory protection program before granting provisional approval;
    (c) Obtain provisional approval of your ventilation plan from the 
District Manager;
    (d) Have MSHA verify your plan's effectiveness by sampling the 
environment of the DO (Occ 044--longwall operator) or other occupation 
directed by the District Manager and those miners working downwind of 
the DO who are required to wear approved PAPRs on the longwall face 
following the verification sampling procedures in Secs. 70.205 and 
70.206;
    (e) Maintain and monitor compliance with the revised ventilation 
plan; and
    (f) Continue to look for improvements that you can make and 
implement feasible solutions when they become available that would 
maintain the environment of the miners required to wear PAPRs at or 
below the verification limits.


Sec. 70.213  For my longwall operation, when will MSHA approve my 
interim ventilation plan incorporating a PAPR respiratory protection 
program?

    MSHA will approve your interim ventilation plan when:
    (a) None of the verification samples for the DO exceed the critical 
values for respirable coal mine dust and quartz dust specified in 
Sec. 70.209;
    (b) None of the verification samples for the miners working 
downwind of the DO, who are required to wear approved PAPRs, exceed the 
following critical values for respirable coal mine dust and quartz 
dust:
    (1) For respirable coal mine dust, the value is:
    (i) 3.54 mg/m\3\ if samples are collected for only one shift;
    (ii) 3.77 mg/m\3\ if samples are collected for two shifts;
    (iii)3.89 mg/m\3\ if samples are collected for three shifts;
    (iv) 4.0 mg/m\3\ if samples are collected for four or more shifts.
    (2) For respirable quartz dust, the value is:
    (i) 174 g/m \3\ if samples are collected for only one 
shift;
    (ii) 187 g/m \3\ if samples are collected for two shifts;
    (iii) 194 g/m \3\ if samples are collected for three 
shifts;
    (iv) 200 g/m \3\ if samples are collected for four or more 
shifts; and
    (c) You adjust your plan, if necessary, to include all the dust 
control parameters that were in effect during verification sampling.


Sec. 70.214  For my longwall operation, under what circumstances may I 
(the operator) continue to use PAPRs to supplement engineering or 
environmental controls?

    You may continue to use approved PAPRs for compliance purposes 
under the following conditions:
    (a) You implement and maintain all feasible engineering or 
environmental controls on each shift;
    (b) You implement and maintain the PAPR respiratory protection 
program as approved by the District Manager;
    (c) No MSHA DO sample exceeds the applicable dust standards, and no 
MSHA sample for any miner working downwind of the DO and required to 
wear a PAPR exceeds two times the applicable dust standards; and
    (d) You continue to look for improvements that you can make and 
implement feasible solutions when they become available that would 
maintain the environment of the miners required to wear PAPRs at or 
below the verification limits.


Sec. 70.215  What if an MSHA DO sample exceeds the applicable dust 
standard, or an MSHA sample for a miner required to wear a PAPR exceeds 
twice the applicable dust standard?

    If an MSHA DO sample exceeds the dust standard you must:
    (a) Promptly review your dust control procedures to determine the 
cause of the high dust concentration levels and take appropriate action 
to prevent similar occurrences in the future;
    (b) Promptly review the continued effectiveness of your approved 
PAPR respiratory protection program; and
    (c) If necessary, make changes to your dust control parameters and 
submit them to the District Manager for review and approval.

Use of Verifiable Administrative Controls


Sec. 70.216  For my longwall operation, what must I (the operator) do 
in order to use verifiable administrative controls to supplement 
engineering or environmental controls?

    In order to use administrative controls for longwall operations you 
must:
    (a) Submit a revised ventilation plan to the District Manager 
within 5 days of receiving notification allowing you to supplement the 
engineering or environmental controls on your longwall for compliance 
purposes. The plan must include the feasible engineering or 
environmental controls being used to reduce the concentrations of 
respirable dust on your longwall to as low a level as possible, the 
verifiable administrative controls to be implemented on the MMU, and a 
method for ensuring that the administrative controls are complied with 
at all times;
    (b) Obtain provisional approval of your ventilation plan from the 
District Manager;
    (c) Have MSHA verify your plan's effectiveness by sampling all 
miners working along the longwall face, including the DO (Occ 044--
longwall operator) or other occupation designated by the District 
Manager;
    (d) Maintain and monitor compliance with the revised ventilation 
plan; and
    (e) Continue to look for improvements that you can make and 
implement feasible solutions when they become available that would 
maintain the environment of the miners required to work downwind of the 
DO and whose exposure is being controlled by administrative controls at 
or below the verification limits.


Sec. 70.217  For my longwall operation, when will MSHA approve my 
interim ventilation plan incorporating verifiable administrative 
controls?

    MSHA will approve your interim ventilation plan and use of 
administrative controls on your longwall when:
    (a) None of the verification samples exceed the critical values for 
respirable coal mine dust and quartz dust specified in Sec. 70.209; and
    (b) Adjust your plan if necessary, to include all the dust control 
parameters that were in effect during verification sampling.


Sec. 70.218  For my longwall operation with an approved interim 
ventilation plan, what must I (the operator) do if an MSHA sample 
exceeds the applicable dust standard?

    If an MSHA sample exceeds the dust standard you must:
    (a) Promptly review your dust control procedures to determine the 
cause of the excessive dust concentration(s) and take appropriate 
action to prevent similar occurrences in the future;
    (b) Promptly review the continued effectiveness of the 
administrative controls in use; and
    (c) If necessary, make changes to your dust control parameters and 
submit them to the District Manager for review and approval.

[[Page 42182]]

Actions Necessary When in Violation of Respirable Dust Standards


Sec. 70.219  What must I (the operator) do if I am cited for exceeding 
the applicable dust standard?

    If you are cited for exceeding the dust standard, you must:
    (a) Promptly review your dust control procedures to determine the 
cause of the excessive dust concentration(s); and
    (b) Take corrective action to lower the concentration of respirable 
dust to comply with the applicable standard and notify the District 
Manager within 24 hours after implementing the corrective action(s). 
MSHA will then sample to determine the effectiveness of your abatement 
actions or require reverification of your ventilation plan under 
proposed Sec. 70.203. If MSHA samples demonstrate:
    (1) Compliance--you must incorporate these corrective actions in 
your mine ventilation plan. MSHA may re-verify your ventilation plan 
after determining that your dust control parameters originally approved 
may be ineffective in controlling the concentrations of respirable dust 
in the working environment of the MMU under the current mining 
conditions.
    (2) Noncompliance--the District Manager may revoke approval of your 
mine ventilation plan.

Information to Be Posted on the Mine Bulletin Board


Sec. 70.220  What information must I (the operator) post on the mine 
bulletin board?

    You must post the following information on the mine bulletin board:
    (a) All MSHA sample results;
    (b) For each MMU, the engineering and environmental controls and 
other practices in effect on each shift of the verification process, 
along with the associated values of the dust control parameters 
measured;
    (c) All written notifications from the District Manager regarding 
any aspect of the plan verification process.
    (d) You may remove the posted verification results after the 
District Manager approves the plan. You must post the results of MSHA 
respirable dust compliance samples upon receipt for 31 days.

Status Change Reports


Sec. 70.221  What action must I (the operator) take if the operational 
status of my mine, MMU, or DA changes?

    (a) You must report the change in operational status of the mine, 
MMU, or DA to the MSHA District Office or to any other MSHA office 
designated by the District Manager. You must report status changes in 
writing within 3 working days after the status change has occurred.
    (b) Each specific operational status is defined as follows:
    (1) Underground mine:
    (i) Producing--has at least one mechanized mining unit producing 
material.
    (ii) Nonproducing--no material is being produced.
    (iii) Abandoned--the work of all miners has been terminated and 
production activity has ceased.
    (2) Mechanized Mining Unit:
    (i) Producing--producing material from a working section.
    (ii) Nonproducing--temporarily ceased production of material.
    (iii) Abandoned--permanently ceased production of material.
    (3) Designated Area:
    (i) Producing--activity is occurring.
    (ii) Nonproducing--activity has ceased.
    (iii) Abandoned--the dust generating source has been withdrawn and 
activity has ceased.

PART 75--[AMENDED]

    6. The authority citation for part 75 continues to read as follows:

    Authority: 30 U.S.C. 811.

    7. Paragraph (h) of Sec. 75.370 of Subpart D is added to read as 
follows:


Sec. 75.370  Mine ventilation plan; submission and approval.

* * * * *
    (h) The operator must record the amount of material produced by 
each MMU during each production shift, retain the records for six 
months, and make the records available to authorized representatives of 
the Secretary and the miners' representative.
    8. Section 75.371 of Subpart D is amended by revising paragraphs 
(f) and (t) to read as follows:


Sec. 75.371  Mine ventilation plan; contents.

* * * * *
    (f) Section and face ventilation systems used, including drawings 
illustrating how each system is used; and a description of each 
different dust suppression system used on equipment on working 
sections, including any specific work practices used to minimize the 
dust exposure of individual miners, along with information on the 
location of the roof bolter(s) during the mining cycle for each 
continuous miner section, and the cut sequence for each longwall mining 
section. For plans required to be verified pursuant to Sec. 70.201, the 
length of each normal production shift, the verification production 
level (VPL) as defined in Sec. 70.2, and additional provisions for the 
use of powered, air purifying respirators (PAPRs) or verifiable 
administrative controls required under Sec. 70.212-215 and Sec. 70.216-
218, respectively, must be included for each working section.
* * * * *
    (t) The location of each ``designated area,'' and the respirable 
dust measures used at the dust generating sources for these locations.

PART 90--[Amended]

    9. The authority citation for part 90 continues to read as follows:

    Authority: 30 U.S.C. 811, 813(h).

    10. Subpart A is revised to read as follows:

Sec.
90.1   Scope.
90.2   Definitions.
90.3   Part 90 option; notice of eligibility; exercise of option.


Sec. 90.1  Scope.

    This part 90 establishes the option of miners who are employed at 
underground coal mines or at surface work areas of underground coal 
mines and who have evidence of the development of pneumoconiosis to 
work in an area of a mine where the average concentration of respirable 
dust in the mine atmosphere during each shift is continuously 
maintained at or below 1.0 milligrams per cubic meter of air. The rule 
sets forth procedures for miners to exercise this option, and 
establishes the right of miners to retain their regular rate of pay and 
receive wage increases. The rule also sets forth the operator's 
obligations. This part 90 is promulgated pursuant to section 101 of the 
Act and supercedes section 203(b) of the Act.


Sec. 90.2  Definitions.

    (a) Act means the Federal Mine Safety and Health Act of 1977, 
Public Law 91-173, as amended by Public Law 95-164, 30 U.S.C. 801 et 
seq.
    (b) Active workings means any place in a coal mine where miners are 
normally required to work or travel.
    (c) Concentration means an 8-hour MRE equivalent measure of the 
amount respirable dust per unit volume of air. The concentration of 
respirable dust is determined in two steps. First, divide the weight of 
dust in milligrams collected on the filter of an approved sampling 
device by 480 minutes times the sampler flow rate. Second, multiply 
that concentration by a constant factor prescribed by the Secretary for 
the approved sampling device used. The product is the equivalent 
concentration as measured with an MRE instrument.

[[Page 42183]]

    (d) District Manager means the manager of the Coal Mine Safety and 
Health District in which the mine is located.
    (e) Mechanized mining unit (MMU) means:
    (1) A unit of mining equipment including hand loading equipment 
used for the production of material; or
    (2) A specialized unit which utilizes mining equipment other than 
specified in Sec. 70.206(c). MSHA assigns each MMU a four digit 
identification number. The MMU retains the identification number 
regardless of where the unit relocates within the mine. When two sets 
of mining equipment are provided in a series of working places and only 
one production crew is employed at any given time on either set of 
mining equipment, the two sets of equipment are be identified as a 
single MMU. When two or more MMUs are simultaneously engaged in the 
production of material within the same working section, each such MMU 
is identified separately.
    (f) MRE means the Mining Research Establishment, of the National 
Coal Board, London, England.
    (g) MRE instrument means the gravimetric dust sampler with a four 
channel horizontal elutriator developed by the Mining Research 
Establishment of the National Coal Board, London, England.
    (h) MSHA means the Mine Safety and Health Administration of the 
Department of Labor.
    (i) Normal work duties means duties which the part 90 miner 
performs on a routine day-to-day basis in his or her job classification 
at a mine.
    (j) Part 90 miner means a miner employed at an underground coal 
mine or at a surface work area of an underground coal mine who has 
exercised the option under the old section 203(b) program (36 FR 20601, 
October 27, 1971), or under Sec. 90.3 (part 90 option; notice of 
eligibility; exercise of option) of this part to work in an area of a 
mine where the average concentration of respirable dust in the mine 
atmosphere during each shift to which that miner is exposed is 
continuously maintained at or below 1.0 milligrams per cubic meter of 
air, and who has not waived these rights.
    (k) Quartz means crystalline silicon dioxide (SiO2) as 
measured by MSHA's Analytical Method P-7: Infrared Determination of 
Quartz in Respirable Coal Mine Dust.
    (l) Respirable dust means dust collected with a sampling device 
approved by the Secretary and the Secretary of Health and Human 
Services in accordance with part 74 (Coal Mine Dust Personal Sampler 
Units) of this title. Sampling device approvals issued by the Secretary 
of the Interior and Secretary of Health, Education, and Welfare are 
continued in effect.
    (m) Secretary means the Secretary of Labor or a designee.
    (n) Secretary of Health and Human Services means Secretary of 
Health and Human Services or Secretary of Health, Education, and 
Welfare.
    (o) Surface work area of an underground coal mine means the surface 
areas of land and all structures, facilities, machinery, tools, 
equipment, shafts, slopes, excavations, and other property, real or 
personal, placed upon or above the surface of such land by any person, 
used in, or to be used in, or resulting from, the work of extracting 
bituminous coal, lignite, or anthracite from its natural deposits 
underground by any means or method, and the work of preparing coal so 
extracted, and includes custom coal preparation facilities.
    (p) Transfer means any change in the work assignment of a part 90 
miner by the operator and includes:
    (1) Any change in occupation code of a part 90 miner;
    (2) Any movement of a part 90 miner to or from a mechanized mining 
unit; or
    (3) Any assignment of a part 90 miner to the same occupation in a 
different location at a mine.
    (q) Underground coal mine means an area of land and all structures, 
facilities, machinery, tools, equipment, shafts, slopes, tunnels, 
excavations, and other property, real or personal, placed upon, under, 
or above the surface of such land by any person, used in, or to be used 
in, or resulting from the work of extracting in such area bituminous 
coal, lignite, or anthracite from its natural deposits in the earth by 
any means or method, and the work of preparing the coal so extracted.


Sec. 90.3  Part 90 option; notice of eligibility; exercise of option.

    (a) Any miner employed at an underground coal mine or at a surface 
work area of an underground coal mine who, in the judgment of the 
Secretary of Health and Human Services, has evidence of the development 
of pneumoconiosis based on a chest X-ray, read and classified in the 
manner prescribed by the Secretary of Health and Human Services, or 
based on other medical examinations shall be afforded the option to 
work in an area of a mine where the average concentration of respirable 
dust in the mine atmosphere during each shift to which that miner is 
exposed is continuously maintained at or below 1.0 milligrams per cubic 
meter of air. Each of these miners shall be notified in writing of 
eligibility to exercise the option.
    (b) Any miner who is a section 203(b) miner on January 31, 1981, 
shall be a part 90 miner on February 1, 1981, entitled to full rights 
under this part to retention of pay rate, future actual wage increases, 
and future work assignment, shift and respirable dust protection.
    (c) Any part 90 miner who is transferred to a position at the same 
or another coal mine shall remain a part 90 miner entitled to full 
rights under this part at the new work assignment.
    (d) The option to work in a low dust area of the mine may be 
exercised for the first time by any miner employed at an underground 
coal mine or at a surface work area of an underground coal mine who was 
eligible for the option under the old section 203(b) program (36 FR 
20601, October 27, 1971), or is eligible for the option under this part 
by signing and dating the Exercise of Option Form and mailing the form 
to the Chief, Division of Health, Coal Mine Safety and Health, MSHA, 
4015 Wilson Boulevard, Arlington, Virginia 22203.
    (e) The option to work in a low dust area of the mine may be re-
exercised by any miner employed at an underground coal mine or at a 
surface work area of an underground coal mine who exercised the option 
under the old section 203(b).
    12. Subpart B is revised to read as follows:
Subpart B--Dust Standards, Rights of Part 90 Miners
Sec.
90.100   Respirable dust standard.
90.101   Respirable dust standard when quartz is present.
90.102   Transfer; notice.
90.103   Compensation.
90.104   Waiver of rights; re-exercise of option.

Subpart B--Dust Standards, Rights of Part 90 Miners


Sec. 90.100  Respirable dust standard.

    After the twentieth calendar day following receipt of notification 
from MSHA that a part 90 miner is employed at the mine, the operator 
shall continuously maintain the average concentration of respirable 
dust in the mine atmosphere during each shift to which the part 90 
miner in the active workings of the mine is exposed at or below 1.0 
milligrams per cubic meter of air.


Sec. 90.101  Respirable dust standard when quartz is present.

    When the respirable dust in the mine atmosphere of the active 
workings to

[[Page 42184]]

which a part 90 miner is exposed contains more than 5 percent quartz, 
the operator shall continuously maintain the average concentration of 
respirable dust in the mine atmosphere during each shift to which a 
part 90 miner is exposed at or below a concentration of respirable dust 
computed by dividing the percent of quartz into the number 10. The 
application of the formula shall not result in a respirable dust 
standard in excess of 1.0 milligrams per cubic meter of air.
    Example: The respirable dust associated with a part 90 miner 
contains quartz in the amount of 20%. Therefore, the average 
concentration of respirable dust in the mine atmosphere associated 
with that part 90 miner shall be continuously maintained at or below 
0.5 milligrams of respirable dust per cubic meter of air (10/20=0.5 
mg/m\3\).


Sec. 90.102  Transfer; notice.

    (a) Whenever a part 90 miner is transferred in order to meet the 
respirable dust standard in Sec. 90.100 (Respirable dust standard) or 
Sec. 90.101 (Respirable dust standard when quartz is present), the 
operator shall transfer the miner to an existing position at the same 
coal mine on the same shift or shift rotation on which the miner was 
employed immediately before the transfer. The operator may transfer a 
part 90 miner to a different coal mine, a newly-created position or a 
position on a different shift or shift rotation if the miner agrees in 
writing to the transfer.
    (b) On or before the twentieth calendar day following receipt of 
notification from MSHA that a part 90 miner is employed at the mine, 
the operator shall give the District Manager written notice of the 
occupation and, if applicable, the mechanized mining unit to which the 
part 90 miner will be assigned on the twenty-first calendar day 
following receipt of the notification from MSHA.
    (c) After the twentieth calendar day following receipt of 
notification from MSHA that a part 90 miner is employed at the mine, 
the operator shall give the District Manager written notice before any 
transfer of a part 90 miner. This notice shall include the scheduled 
date of the transfer.


Sec. 90.103  Compensation.

    (a) The operator shall compensate each part 90 miner at not less 
than the regular rate of pay received by that miner immediately before 
exercising the option under Sec. 90.3 (part 90 option; notice of 
eligibility; exercise of option).
    (b) Whenever a part 90 miner is transferred, the operator shall 
compensate the miner at not less than the regular rate of pay received 
by that miner immediately before the transfer.
    (c) The operator shall compensate each miner who is a section 
203(b) miner on January 31, 1981, at not less than the regular rate of 
pay that the miner is required to receive under section 203(b) of the 
Act immediately before the effective date of this part.
    (d) In addition to the compensation required to be paid under 
paragraphs (a), (b) and (c) of this section, the operator shall pay 
each part 90 miner the actual wage increases that accrue to the 
classification to which the miner is assigned.
    (e) If a miner is temporarily employed in an occupation other than 
his or her regular work classification for two months or more before 
exercising the option under Sec. 90.3 (part 90 option; notice of 
eligibility; exercise of option), the miner's regular rate of pay for 
purposes of paragraph (a) and (b) of this section is the higher of the 
temporary or regular rates of pay. If the temporary assignment is for 
less than two months, the operator may pay the part 90 miner at his or 
her regular work classification rate regardless of the temporary wage 
rate.
    (f) If a part 90 miner is transferred, and the Secretary 
subsequently notifies the miner that notice of the miner's eligibility 
to exercise the part 90 option was incorrect, the operator shall retain 
the affected miner in the current position to which the miner is 
assigned and continue to pay the affected miner the applicable rate of 
pay provided in paragraphs (a), (b), (c) and (d) of this section, 
until:
    (1) The affected miner and operator agree in writing to a position 
with pay at not less than the regular rate of pay for that occupation; 
or
    (2) A position is available at the same coal mine in both the same 
occupation and on the same shift on which the miner was employed 
immediately before exercising the option under Sec. 90.3 (Part 90 
option; notice of eligibility; exercise of option) or under the old 
section 203(b) program (36 FR 20601, October 27, 1971).
    (i) When such a position is available, the operator shall offer the 
available position in writing to the affected miner with pay at not 
less than the regular rate of pay for that occupation.
    (ii) If the affected miner accepts the available position in 
writing, the operator shall implement the miner's reassignment upon 
notice of the miner's acceptance. If the miner does not accept the 
available position in writing, the miner may be reassigned and 
protections under Part 90 shall not apply. Failure by the miner to act 
on the written offer of the available position within 15 days after 
notice of the offer is received from the operator shall operate as an 
election not to accept the available position.


Sec. 90.104  Waiver of rights; re-exercise of option.

    (a) A part 90 miner may waive his or her rights and be removed from 
MSHA's active list of miners who have rights under part 90 by:
    (1) Giving written notification to the Chief, Division of Health, 
Coal Mine Safety and Health, MSHA, that the miner waives all rights 
under this part;
    (2) Applying for and accepting a position in an area of a mine 
which the miner knows has an average respirable dust concentration 
exceeding 1.0 milligrams per cubic meter of air or the respirable dust 
standard established by Sec. 90.101 (Respirable dust standard when 
quartz is present); or
    (3) Refusing to accept another position offered by the operator at 
the same coal mine that meets the requirements of Secs. 90.100, 90.101 
and 90.102(a) after MSHA dust sampling shows that the average 
respirable dust concentration in his or her present position exceeds 
1.0 milligrams per cubic meter of air or the respirable dust standard 
established by Sec. 90.101 (Respirable dust standard when quartz is 
present).
    (b) If rights under part 90 are waived, the miner gives up all 
rights under part 90 until the miner re-exercises the option in 
accordance with Sec. 90.3(e) (part 90 option; notice of eligibility; 
exercise of option).
    (c) If rights under part 90 are waived, the miner may re-exercise 
the option under this part in accordance with Sec. 90.3(e) (part 90 
option; notice of eligibility; exercise of option) at any time.
    13. Subpart C is revised to read as follows:

90.201  MSHA respirable dust sample reports; operator status change 
reporting requirement.
90.202  Operator status change reports.

Sec. 90.201  MSHA Respirable dust sample reports; Operator status 
change reporting requirement.

    (a) The Secretary shall provide the operator with a report of the 
following data on the MSHA respirable dust samples as soon as 
practicable:
    (1) The mine identification number;
    (2) The mechanized mining unit, if any, within the mine from which 
the samples were taken;
    (3) The concentration of respirable dust, expressed in milligrams 
per cubic meter of air, for each valid sample;
    (4) The average concentration of respirable dust, expressed in 
milligrams

[[Page 42185]]

per cubic meter of air, for all valid samples;
    (5) The occupation code;
    (6) The reason for voiding any samples; and,
    (7) The Social Security Number of the part 90 miner.
    (b) Upon receipt, the operator shall provide a copy of this report 
to the part 90 miner. The operator shall not post the original or a 
copy of this report on the mine bulletin board.


Sec. 90.202  Operator status change reports.

    If there is a change in the status of a part 90 miner (such as 
entering a terminated, injured or ill status, or returning to work), 
the operator must report the change in the status of the part 90 miner 
to the MSHA District Office or to any other MSHA office designated by 
the District Manager. Status changes shall be reported in writing 
within 3 working days after the status change has occurred.

[FR Doc. 00-16149 Filed 7-6-00; 8:45 am]
BILLING CODE 4510-43-P