[Federal Register Volume 73, Number 41 (Friday, February 29, 2008)]
[Rules and Regulations]
[Pages 11284-11304]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-3828]



[[Page 11283]]

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Part IV





Department of Labor





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Mine Safety and Health Administration



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30 CFR Parts 56, 57, and 71



Asbestos Exposure Limit; Final Rule

  Federal Register / Vol. 73, No. 41 / Friday, February 29, 2008 / 
Rules and Regulations  

[[Page 11284]]


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DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 56, 57, and 71

RIN 1219-AB24


Asbestos Exposure Limit

AGENCY: Mine Safety and Health Administration, Labor.

ACTION: Final rule.

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SUMMARY: The Mine Safety and Health Administration (MSHA) is revising 
its existing health standards for asbestos exposure at metal and 
nonmetal mines, surface coal mines, and surface areas of underground 
coal mines. This final rule reduces the permissible exposure limits for 
airborne asbestos fibers and makes clarifying changes to the existing 
standards. Exposure to asbestos has been associated with lung cancer, 
mesothelioma, and other cancers, as well as asbestosis and other 
nonmalignant respiratory diseases. This final rule will help improve 
health protection for miners who work in an environment where asbestos 
is present and lower the risk that miners will suffer material 
impairment of health or functional capacity over their working 
lifetime.

DATES: This final rule is effective April 29, 2008.

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey at 
[email protected] (E-mail), 202-693-9440 (Voice), or 202-693-9441 
(Fax).

SUPPLEMENTARY INFORMATION: The outline of this preamble is as follows:

I. Summary
II. Background to the Final Rule
    A. Scope of Final Rule
    B. Mineralogy and Analytical Methods for Asbestos
    C. Summary of Asbestos Health Hazards
    D. Factors Affecting the Occurrence and Severity of Disease
    E. MSHA Asbestos Standards
    F. OSHA Asbestos Standards
III. Asbestos Exposures in Mines
    A. Where Asbestos Is Found at Mines
    B. Sampling Data and Exposure Calculations
    C. Summary of MSHA's Asbestos Air Sampling and Analysis Results
    D. Prevention of Asbestos Take-Home Contamination
IV. Application of OSHA'S Risk Assessment to Mining
    A. Summary of OSHA's Risk Assessment
    B. Risk Assessment for the Mining Industry
    C. Characterization of the Risk to Miners
V. Section-by-Section Analysis of Final Rule
    A. Sections 56/57.5001(b)(1) and 71.702(a): Definitions
    B. Sections 56/57.5001(b)(2) and 71.702(b): Permissible Exposure 
Limits (PELs)
    C. Sections 56/57.5001(b)(3) and 71.702(c): Measurement of 
Airborne Fiber Concentration
    D. Section 71.701(c) and (d): Sampling; General Requirements
VI. Regulatory Analyses
    A. Executive Order (E.O.) 12866
    B. Feasibility
    C. Alternatives Considered
    D. Regulatory Flexibility Analysis (RFA) and Small Business 
Regulatory Enforcement Fairness Act (SBREFA)
    E. Other Regulatory Considerations
VII. Copy of the OSHA Reference Method (ORM)
VIII. References Cited in the Preamble

I. Summary

    The final rule lowers MSHA's permissible exposure limits (PELs) for 
asbestos; incorporates the Occupational Safety and Health 
Administration (OSHA) Reference Method (29 CFR 1910.1001, Appendix A) 
for MSHA's analysis of mine air samples for asbestos; and makes several 
clarifying changes to MSHA's existing rule. MSHA is issuing this health 
standard limiting miners' exposure to asbestos under section 
101(a)(6)(A) of the Federal Mine Safety and Health Act of 1977 (Mine 
Act). MSHA based this final rule on its experience, an assessment of 
the health risks of asbestos, OSHA's rulemaking history and enforcement 
experience with its asbestos standard and public comments and testimony 
on MSHA's asbestos proposed rule.
    To protect the health of miners, this final rule lowers MSHA's 8-
hour, time-weighted average (TWA), full-shift PEL from 2 fibers per 
cubic centimeter of air (f/cc) to 0.1 f/cc. The existing excursion 
limit for metal and nonmetal mines is 10 fibers per milliliter (f/mL) 
for 15 minutes and the existing excursion limit for coal mines is 10 f/
cc for a total of 1 hour in each 8-hour day. This final rule lowers 
these existing excursion limits to 1 f/cc for 30 minutes. Together, 
these lower PELs significantly reduce the risk of material impairment 
for exposed miners. These final PELs are the same as proposed and the 
same as OSHA's asbestos exposure limits. Although OSHA stated in the 
preamble to its 1994 final rule (59 FR 40967) that there is a remaining 
significant risk of material impairment of health or functional 
capacity at the 0.1 f/cc limit, OSHA concluded that this concentration 
is ``the practical lower limit of feasibility for measuring asbestos 
levels reliably.'' MSHA agrees with this conclusion.
    To clarify the criteria for the analytical method that MSHA will 
use to analyze mine air samples for asbestos under this final rule, the 
rule includes a reference to Appendix A of OSHA's asbestos standard (29 
CFR 1910.1001). Appendix A specifies basic elements of a phase contrast 
microscopy (PCM) method for analyzing airborne asbestos samples, which 
includes the same basic analytical elements as those specified in 
MSHA's existing standards.
    Because the risk assessment used as the basis for MSHA's asbestos 
PELs relies on PCM-based methodology, MSHA will continue to use PCM as 
the primary methodology for analyzing air samples to determine 
compliance with the PELs. PCM provides a relatively quick and cost-
effective analysis of asbestos samples. In addition, MSHA will continue 
to follow-up with its policy of using a transmission electron 
microscopy (TEM) analysis when PCM results indicate a potential 
overexposure.
    MSHA, however, encourages the development of analytical methods 
specifically for asbestos in mine air samples. MSHA will consider using 
a method statistically equivalent to Appendix A, if it meets the OSHA 
Reference Method (ORM) equivalency criteria in OSHA's asbestos standard 
[29 CFR 1910.1001(d)(6)(iii)] and is recognized by a laboratory 
accreditation organization. For example, ASTM D7200-06, ``Standard 
Practice for Sampling and Counting Airborne Fibers, Including Asbestos 
Fibers, in Mines and Quarries, by Phase Contrast Microscopy and 
Transmission Electron Microscopy,'' contains the same procedure as 
NIOSH 7400 to identify fibers. ASTM D7200-06 then has an additional 
procedure to discriminate potential asbestos fibers, which NIOSH 7400 
does not. NIOSH is supporting an ASTM inter-laboratory study to 
determine whether this additional procedure can be performed accurately 
and consistently. This procedure was developed in part as a result of 
this rulemaking and has not been validated.

II. Background to the Final Rule

A. Scope of Final Rule

    This final rule applies to all metal and nonmetal mines, surface 
coal mines, and surface areas of underground coal mines. It is 
substantively unchanged from the proposed rule and contains the same 
PELs and analytical method as in OSHA's asbestos standard. Some 
commenters supported additional changes to MSHA's definition of 
asbestos and its analytical method. Others recommended that MSHA 
propose additional requirements from the OSHA asbestos standard to 
prevent take-home contamination. Such changes were not contemplated in 
the proposed

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rule and, therefore, are beyond the scope of this final rule.

B. Mineralogy and Analytical Methods for Asbestos

    Asbestos is a generic term used to describe the fibrous habits of 
specific naturally occurring, hydrated silicate minerals. Several 
federal agencies \1\ have regulations that address six asbestos 
minerals: chrysotile, crocidolite, cummingtonite-grunerite asbestos 
(amosite), actinolite asbestos, anthophyllite asbestos, and tremolite 
asbestos. Other agencies address asbestos more generally.\2\
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    \1\ In addition to MSHA's and OSHA's existing worker protection 
standards, other federal statutory and regulatory requirements that 
apply only to the six commercial varieties of asbestos include the 
Asbestos Hazard Emergency Response Act (AHERA) [15 U.S.C. 2642(3)] 
and the Clean Air Act's National Emission Standards for Hazardous 
Air Pollutants (NESHAP) [40 CFR 61.141].
    \2\ Asbestos is listed as a hazardous air pollutant under the 
Clean Air Act [42 U.S.C. 7412(b)(1)]; as a hazardous substance under 
the Comprehensive Environmental Response, Compensation and Liability 
Act [40 CFR 302.4]; and in EPA's Integrated Risk Information System 
(IRIS), a collection of health assessment information regarding the 
toxicity of asbestos, http://www.epa.gov/IRIS/susbst/0371.htm.
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    The terminology used to refer to how minerals form and how they are 
named is complex. Much of the existing health risk data for asbestos 
uses the commercial mineral terminology.\3\ In the asbestiform habit, 
mineral crystals grow forming long, thread-like fibers. The U.S. Bureau 
of Mines defined asbestiform minerals to be ``a certain type of mineral 
fibrosity in which the fibers and fibrils possess high tensile strength 
and flexibility.'' \4\ When light pressure is applied to an asbestiform 
fiber, it bends much like a wire, rather than breaks. In the 
nonasbestiform habit, mineral crystals do not grow in long thin fibers; 
they grow in a more massive habit. When pressure is applied, the 
nonasbestiform crystals fracture into prismatic particles, which are 
called cleavage fragments because they result from the particle's 
breaking or cleavage. Cleavage fragments may be formed when nonfibrous 
minerals are crushed, as may occur in mining and milling operations. 
Distinguishing between asbestiform fibers and cleavage fragments in 
certain size ranges can be difficult or impossible for some 
minerals.\5\
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    \3\ Asbestos mineralogy was discussed more fully in the proposed 
rule (70 FR 43952-43953).
    \4\ U.S. Bureau of Mines (Campbell et al.), 1977.
    \5\ Meeker et al., 2003.
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C. Summary of Asbestos Health Hazards

    Studies first identified health problems associated with 
occupational exposure to asbestos in the early 20th century among 
workers involved in the manufacturing or use of asbestos-containing 
products.\6\ These studies identified the inhalation of asbestos as the 
cause of asbestosis, a slowly progressive disease that produces lung 
scarring and loss of lung elasticity. Studies also found that asbestos 
caused lung and several other types of cancer.\7\ For example, 
mesotheliomas, rare cancers of the lining of the chest or abdominal 
cavities, are almost exclusively attributable to asbestos exposure. 
Once diagnosed, they are rapidly fatal. The damage following many years 
of workplace exposure to asbestos is generally cumulative and 
irreversible. Most asbestos-related diseases have long latency periods, 
typically not producing symptoms for 20 to 30 years following initial 
exposure. Studies also indicate adverse health effects in workers who 
have had relatively brief exposures to asbestos.\8\
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    \6\ GETF Report, p. 38, 2003; OSHA (40 FR 47654), 1975.
    \7\ Doll, 1955; Reeves et al., 1974; Becker et al., 2001; Browne 
and Gee, 2000; Sali and Boffetta, 2000; IARC, 1987.
    \8\ Sullivan, 2007.
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    Several studies have examined respiratory health and respiratory 
symptoms of asbestos-exposed workers.\9\ Asbestos-induced pleurisy is 
the most common asbestos-related condition to occur during the 20-year 
period immediately following a worker's first exposure to asbestos.\10\ 
Pleural plaques may develop within 10-20 years after an initial 
asbestos exposure \11\ and slowly progress in size and amount of 
calcification, independent of any further exposure. Diffuse pleural 
thickening and pleural plaques are biologic markers reflecting previous 
asbestos exposure.\12\ In addition, presence in lung tissue of asbestos 
fibers with a coating of iron and protein, called asbestos bodies, is 
one of the criteria that serve to support a pathologic diagnosis of 
asbestosis.\13\ These nonmalignant respiratory conditions can be used 
to identify at-risk miners prior to their developing a more serious 
asbestos disease.
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    \9\ Wang et al., 2001; Delpierre et al., 2002; Eagen et al., 
2002; Selden et al., 2001.
    \10\ Rudd, 2002.
    \11\ Bolton et al., 2002; OSHA, 1986.
    \12\ ATSDR, 2001; Manning et al., 2002.
    \13\ ATSDR, 2001; Peacock et al., 2000; Craighead et al, 1982.
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    Because the hazardous effects from exposure to asbestos are well 
known, MSHA's discussion in this section will focus on the results of 
studies and literature reviews published since the publication of 
OSHA's risk assessment, and those involving miners. One such review by 
Tweedale (2002) stated,

    Asbestos has become the leading cause of occupational related 
cancer death, and the second most fatal manufactured carcinogen 
(after tobacco). In the public's mind, asbestos has been a hazard 
since the 1960s and 1970s. However, the knowledge that the material 
was a mortal health hazard dates back at least a century, and its 
carcinogenic properties have been appreciated for more than 50 
years.

Greenberg (2003) also published a recent review of the biological 
effects of asbestos and provided a historical perspective similar to 
that of Tweedale.
    The three most commonly described adverse health effects associated 
with asbestos exposure are lung cancer, mesotheliomas, and pulmonary 
fibrosis (i.e., asbestosis). OSHA, in its 1986 asbestos rule, reviewed 
each of these diseases and provided details on the studies 
demonstrating the relationship between asbestos exposure and the 
clinical evidence of disease.\14\ In 2001, the Agency for Toxic 
Substances and Disease Registry (ATSDR) published an updated 
Toxicological Profile for Asbestos that also included an extensive 
discussion of these three diseases. A search of peer-reviewed 
scientific literature yielded many new articles \15\ that continue to 
demonstrate and support findings of asbestos-induced lung cancer, 
mesotheliomas, and asbestosis, consistent with the conclusions of OSHA 
and ATSDR. Thus, in the scientific community, there is compelling 
evidence of the adverse health effects of asbestos exposure.
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    \14\ Berry and Newhouse, 1983; Dement et al., 1982; Finkelstein, 
1983; Henderson and Enterline, 1979; Peto, 1980; Peto et al., 1982; 
Seidman et al., 1979; Seidman, 1984; Selikoff et al., 1979; Weill et 
al., 1979.
    \15\ Baron, 2001; Bolton et al., 2002; Manning et al., 2002; 
Nicholson, 2001; Osinubi et al., 2000; Roach et al., 2002.
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D. Factors Affecting the Occurrence and Severity of Disease

    The toxicity of asbestos, and the subsequent occurrence of disease, 
is related to its concentration in the air and the duration of 
exposure. Other variables, such as the fiber's characteristics or the 
effectiveness of a person's lung clearance mechanisms, lung fiber 
burden, residence-time-weighted cumulative exposures, and susceptible 
populations are also relevant factors affecting disease severity.\16\
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    \16\ ICRP, 1966; EPA, 1986; West, 2000 and 2003; Manning et al., 
2002.
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1. Fiber Concentration
    Early airborne asbestos dust measurements had counted particles

[[Page 11286]]

and reported the results as millions of particles per cubic foot of air 
(mppcf). Most recent studies express the concentration of asbestos as 
the number of fibers per cubic centimeter (f/cc). Some studies have 
also reported asbestos concentrations in the number of fibers per 
milliliter (f/mL), which is an equivalent concentration to f/cc. MSHA's 
existing PELs for asbestos are expressed in f/mL for metal and nonmetal 
mines and as f/cc for coal mines. To improve consistency and avoid 
confusion, MSHA expresses the concentration of asbestos fibers as f/cc 
in this final rule, for both coal and metal and nonmetal mines.
    In the late 1960s, scientists correlated PCM-based fiber counting 
methods with the earlier types of dust measurements, which provided a 
means to estimate earlier workers' asbestos exposures and enabled 
researchers to develop a dose-response relationship with the occurrence 
of disease. The British Occupational Hygiene Society reported \17\ that 
a worker exposed to 100 fiber-years per cubic centimeter (e.g., 50 
years at 2 f/cc, 25 years at 4 f/cc, 10 years at 10 f/cc) would have a 
1 percent risk of developing early signs of asbestosis. The correlation 
of exposure levels with the disease experience of populations of 
exposed workers provided a basis for setting an occupational exposure 
limit for asbestos measured by the concentration of the fibers in air.
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    \17\ Lane et al., 1968; OSHA (40 FR 47654), 1975; NIOSH, 1980.
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    OSHA (51 FR 22617) applied a conversion factor of 1.4 to convert 
mppcf, which includes all particles of respirable size, to f/cc, which 
includes only those particles greater than 5 [mu]m in length with at 
least a 3:1 aspect ratio. More recently, Hodgson and Darnton (2000) 
recommended the use of a factor of 3. In reviewing the scientific 
literature, MSHA did not critically evaluate the impact of these and 
other conversion factors. MSHA notes this difference here for 
completeness. MSHA is relying on OSHA's risk assessment and, thus, is 
using OSHA's conversion factor.
2. Duration of Exposure
    The duration of exposure (T) is reported in both epidemiological 
and toxicological studies, and is generally much shorter in animal 
studies (e.g., months versus years). In epidemiological studies 
involving toxic substances that do not have acute health effects, such 
as asbestos, duration of exposure is typically expressed in years.
3. Cumulative Exposure
    When developing dose-response relationships for asbestos-induced 
health effects, researchers typically use the product of exposure 
concentration (C in f/cc) and exposure duration (T in years), expressed 
as fiber-years,\18\ to indicate the level of exposure or dose. When 
summed over all periods of exposure, this measure is called cumulative 
exposure. Because of the difficulties in obtaining good quantitative 
exposure assessments, cumulative exposure expressed in fiber-years is 
often selected as the common metric for the levels of exposures 
reported in epidemiological studies.
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    \18\ ATSDR, 2001; Fischer et al., 2002; Liddell, 2001; Pohlabeln 
et al., 2002.
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    Finkelstein\19\ noted that this product of exposure concentration 
times duration of exposure (C x T) assumes an equal weighting of each 
variable (C, T). Finkelstein stated further that exposure at a low 
concentration for a long period of time may be numerically equivalent 
to exposure at a high concentration for short periods of time; but, 
they may not be biologically equivalent. What this means is that, in 
some studies, either concentration or duration of exposure may be more 
important in predicting disease. For example, in the case of 
mesothelioma risk following asbestos exposure, Finkelstein \20\ 
concluded that ``* * * duration of exposure may dominate the exposure 
term * * *''.
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    \19\ Finkelstein, 1995; ATSDR, p. 42, 2001.
    \20\ Finkelstein, 1995
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4. Fiber Characteristics
    Baron (2001) reviewed techniques for the measurement of fibers and 
stated, ``* * * fiber dose, fiber dimension, and fiber durability are 
the three primary factors in determining fiber toxicity * * *''. 
Manning et al. (2002) also noted the important roles of bio-persistence 
(i.e., durability), physical properties, and chemical properties in 
defining the ``toxicity, pathogenicity, and carcinogenicity'' of 
asbestos. Roach et al. (2002) stated that--

    Physical properties, such as length, diameter, length-to-width 
(aspect ratio), and texture, and chemical properties are believed to 
be determinants of fiber distribution [in the body] and disease 
severity.

Many other investigators \21\ also have concluded that the dimensions 
of asbestos fibers are biologically important.
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    \21\ ATSDR, 2001; ATSDR, 2003; Osinubi et al., 2000; Peacock et 
al., 2000; Langer et al., 1979.
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    The NIOSH 7400 analytical method used by MSHA's contract 
laboratories specifies that analysts count those fibers that are 
greater than 5 micrometers (microns, [mu]m) in length with a length to 
diameter aspect ratio of at least 3:1. Several recent publications \22\ 
support this aspect ratio, although larger aspect ratios such as 5:1 or 
20:1 have been proposed.\23\ There is some evidence that longer, 
thinner asbestos fibers (e.g., greater than 20 [mu]m long and less than 
1 [mu]m in diameter) are more potent carcinogens than shorter fibers. 
Suzuki and Yuen (2002), however, concluded that ``Short, thin asbestos 
fibers should be included in the list of fiber types contributing to 
the induction of human malignant mesotheliomas * * * ''. More recently, 
Dodson et al. (2003) concluded that all lengths of asbestos fibers 
induce pathological responses and that researchers should exercise 
caution when excluding a population of inhaled asbestos fibers based on 
their length.
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    \22\ ATSDR, 2001; Osinubi et al., 2000.
    \23\ Wylie et al., 1985.
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    Researchers have found neither a reliable method for predicting the 
contribution of fiber length to the development of disease, nor 
evidence establishing the exact relationship between them. There is 
suggestive evidence that the dimensions of asbestos fibers may vary 
with different diseases. A continuum may exist in which shorter, wider 
fibers produce one disease, such as asbestosis, and longer, thinner 
fibers produce another, such as mesotheliomas.\24\
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    \24\ ATSDR, pp. 39-41, 2001; ATSDR, 2003; Mossman, pp. 47-50, 
2003; Kuempel et al., 2006.
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    Some commenters suggested that MSHA consider additional fiber 
characteristics, such as durability, in evaluating risk. Some 
emphasized that not all fibers with the same dimensions will lead to 
the same disease endpoint. The science is inconclusive on the 
relationship between the various fiber characteristics and the disease 
endpoints.\25\
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    \25\ Hodgson and Darnton, 2000; Browne, 2001; Liddell, 2001; 
ATSDR, 2001.
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E. MSHA Asbestos Standards

    The early PELs for asbestos in mining dropped dramatically as more 
information on the health effects of asbestos exposure became evident 
20 to 30 years (latency period) following its widespread use during the 
1940s.

------------------------------------------------------------------------
               Year                       8-hour TWA, Asbestos PEL
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1967..............................  5 mppcf (30 f/mL)
1969..............................  2 mppcf (12 f/mL)
1974..............................  5 f/mL for metal and nonmetal mines
1976..............................  2 f/cc for surface areas of coal
                                     mines (41 FR 10223)
1978..............................  2 f/mL for metal and nonmetal mines
                                     (43 FR 54064)
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    On March 29, 2002 (67 FR 15134), MSHA published an advance notice 
of proposed rulemaking to obtain public comment on how best to protect 
miners from exposure to asbestos. MSHA published the proposed rule on 
July 29, 2005 (70 FR 43950) and held two public hearings in October 
2005.

F. OSHA's Asbestos Standards

    Like MSHA's, OSHA's 8-hour TWA PEL for occupational exposure to 
asbestos dropped dramatically over the past several decades.

------------------------------------------------------------------------
               Year                        8-hour TWA Asbestos PEL
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1971..............................  12 f/cc
1971..............................  5 f/cc
1972..............................  2 f/cc
1983..............................  0.5 f/cc \26\
1986..............................  0.2 f/cc \27\
1994..............................  0.1 f/cc
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In addition, on September 14, 1988, OSHA promulgated an asbestos 
excursion limit of 1 f/cc over a sampling period of 30 minutes (53 FR 
35610).
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    \26\ U.S. Court of Appeals for the 5th Circuit invalidated this 
rule on March 7, 1984, in Asbestos Information Association/North 
America v. OSHA (727 F.2d 415, 1984).
    \27\ OSHA added specific provisions in the construction standard 
to cover unique hazards relating to asbestos abatement and 
demolition jobs.
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    OSHA's 1986 standards had applied to occupational exposure to both 
asbestiform and nonasbestiform actinolite, tremolite, and anthophylite. 
On June 8, 1992, OSHA removed the nonasbestiform types of these 
minerals from the scope of its asbestos standards (57 FR 24310).

III. Asbestos Exposures in Mines

A. Where Asbestos Is Found at Mines

    Asbestos exposure of miners can come from either naturally 
occurring asbestos in the ore or host rock or from asbestos contained 
in manufactured products.
1. Metal and Nonmetal Mines
    The National Institute for Occupational Safety and Health (NIOSH) 
and other research organizations and scientists have noted the 
occurrence of cancers and asbestosis among miners involved in the 
mining and milling of commodities that contain asbestos.\28\ (See Table 
IV-3.) Although asbestos is no longer mined as a commodity in the 
United States, veins, pockets, or intrusions of asbestos-containing 
minerals have been found in other ores in specific geographic regions, 
primarily in metamorphic or igneous rock.\29\ It is possible to find 
asbestos in sedimentary rock. The U.S. Geological Survey (USGS) has 
reported weathering or abrasion of asbestos-bearing rock and soil, or 
air transportation, to carry asbestos to sedimentary deposits.\30\ 
MSHA's experience is that miners may encounter asbestos during the 
mining of a number of mineral commodities,\31\ such as talc, limestone 
and dolomite, vermiculite, wollastonite, banded ironstone and taconite, 
lizardite, and antigorite. Even if asbestos contamination is found in a 
specific mineral commodity, not all mines of that commodity will 
encounter asbestos and those that do may encounter it rarely. (See 
Table III-1.)
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    \28\ NIOSH WoRLD, 2003.
    \29\ MSHA (Bank), 1980; Ross, 1978.
    \30\ USGS, 1995.
    \31\ Roggli et al., 2002; Selden et al., 2001; Amandus et al., 
Part I, 1987; Amandus et al., Part III, 1987; Amandus and Wheeler, 
Part II, 1987; Meeker et al., 2003.
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    Mining activities, such as blasting, cutting, crushing, grinding, 
or simply disturbing the ore or surrounding earth may cause asbestos 
fibers to become airborne.\32\ Milling may transform bulk ore 
containing asbestos into respirable fibers. Asbestos tends to deposit 
on workplace surfaces and accumulate during the milling process, which 
is often in enclosed buildings. The use of equipment and machinery or 
other activities in these locations may re-suspend the asbestos-
containing dust from these surfaces into the air. For this reason, MSHA 
generally finds higher asbestos concentrations in mills than among 
mobile equipment operators or in ambient environments, such as pits.
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    \32\ MSHA (Bank), 1980; Amandus et al., Part I, 1987.
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    Some mine operators are making an effort to avoid deposits that are 
likely to contain asbestos minerals. They use knowledge of the geology 
of the area, core or bulk sample analysis, and workplace examinations 
(of the pit) to avoid encountering asbestos deposits, thus preventing 
asbestos contamination of their process stream and final product.\33\
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    \33\ GETF Report, pp. 17-18, 2003; Nolan et al., 1999.
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2. Coal Mines
    MSHA is aware of only one coal formation in the United States that 
contains naturally occurring asbestos; however, there is no coal mining 
in this formation.\34\ The more likely exposure to asbestos in coal 
mining occurs at surface operations from introduced asbestos-containing 
materials (ACM).
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    \34\ Brownfield et al., 1995.
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3. Asbestos-Containing Materials (ACM)
    Asbestos is a component in some commercial products and may be 
found as a contaminant in others. The USGS estimates that, during 2006, 
manufacturers in the United States used about 2,340 metric tons (5.2 
million pounds) of asbestos, primarily in roofing products and coatings 
and compounds. In addition to domestic manufacturing, the United States 
continues to import products that contain asbestos, primarily cement 
products, such as flat cement panels, sheets, and tiles.\35\
    Although manufacturers have removed the asbestos from many new 
products,\36\ asbestos may still be found at mines. Asbestos-containing 
building materials (ACBM), such as Transite[reg] board and reinforced 
cements, could present a hazard during maintenance, construction, 
remodeling, rehabilitation, or demolition projects. Asbestos in 
manufactured products, such as electrical insulation, joint and packing 
compounds, automotive clutch and brake linings,\37\ and fireproof 
protective clothing and welding blankets, could present a hazard during 
activities at the mine site that may cause a release of fibers.\38\ 
MSHA expects mine operators to determine whether ACM or ACBM are 
present on mine property by reading the labels or Material Safety Data 
Sheets (MSDS) required by the OSHA Hazard Communication Standard (29 
CFR 1910.1200). The presence of asbestos at a mine indicates that there 
is a potential for exposure.

B. Sampling Data and Exposure Calculations

    To evaluate asbestos exposures in mines, MSHA collects personal 
exposure samples. MSHA samples a miner's entire work shift using a 
personal air-sampling pump and a filter-cassette assembly. This 
assembly is composed of a 50-mm static-reducing, electrically 
conductive, extension cowl and a 0.8 [mu]m pore size, 25-mm diameter, 
mixed cellulose ester (MCE) filter. Following standard sampling 
procedures, MSHA also submits blank filters for analysis.
    MSHA collects a sample over the entire time the miner works; 10- to 
12-hour shifts are common. The time-weighted average (TWA) PELs in 
MSHA's standards, however, are based on an 8-hour workday. Regardless 
of the actual shift length, MSHA calculates a full-shift concentration 
as if the fibers had been collected over an 8-hour shift. For work 
schedules less than or greater than 8 hours, this technique allows MSHA 
to compare a miner's exposure

[[Page 11288]]

directly to the 8-hour TWA PEL. MSHA calls this calculated equivalent, 
8-hour TWA a ``shift-weighted average'' (SWA).
    MSHA's existing sampling procedures specify using several, 
typically three, filter-cassette assemblies in a consecutive series to 
collect a full-shift sample. For results from both PCM and TEM 
analyses, MSHA calculates the SWA exposure levels for each miner 
sampled from the individual filters according to the following 
formulas.
    SWA = (TWA1t1 + TWA2t2 + * * * + TWAntn)/480 minutes

Where:

TWAn is the time-weighted average concentration for filter ``n'' 
calculated by dividing the number of fibers (f) collected on the 
filter by the volume of air (cc) drawn through the filter.
tn is the duration sampled in minutes for filter ``n''.

    Some commenters criticized MSHA's sampling and analytical 
procedures. A few commenters believed that MSHA should develop specific 
test procedures for the sampling and analysis of bulk samples for the 
mining environment, as well as specific air sampling procedures. Some 
commenters suggested that respirable dust sampling using a cyclone 
might be a means to remove interfering dust from the sample. NIOSH 
recommended that thoracic samplers be evaluated in a mining 
environment. Cyclones and thoracic samplers are not included in MSHA's 
existing sampling and analytical protocols for asbestos and are not 
included in existing approved methods. Exposures determined using these 
devices have not been correlated with the risk assessment that forms 
the basis of the PELs in the final rule.
    Some commenters supported MSHA's existing asbestos monitoring 
protocols with emphasis on full-shift monitoring for comparison to the 
PEL. Other commenters stated that MSHA's existing field sampling and 
analysis methods are adequate for most mines and quarries, particularly 
when no significant amount of asbestos is found.
    Some commenters stated that MSHA should improve its inspection 
reports by including inspection field notes; sampling location, 
purpose, and procedure; as well as descriptions of the accuracy, 
meaning, and limitations of the analytical results. MSHA routinely 
provides the sampling and analytical results and, when requested, will 
provide the additional information.

C. Summary of MSHA's Asbestos Air Sampling and Analysis Results

    To assess personal exposures and present the Agency's sampling data 
for January 1, 2000 through May 31, 2007, MSHA calculated an SWA 
exposure for each miner from the TWA results of individual filters. 
MSHA has compiled these data into a PowerPoint[reg] slide, and has 
posted it, together with additional explanatory information, on MSHA's 
Asbestos Single Source Page at http://www.msha.gov/asbestos/asbestos.htm.
---------------------------------------------------------------------------

    \35\ USGS (Virta), 2007.
    \36\ GETF Report, pp. 12 and 15, 2003.
    \37\ Lemen, 2003; Paustenbach et al., 2003.
    \38\ EPA, 1986; EPA, 1993; EPA, October 2003.
---------------------------------------------------------------------------

    MSHA conducted asbestos sampling at 207 mines (206 non-asbestos 
metal and nonmetal mines and one coal mine) during the period January 
1, 2000 through May 31, 2007. Some were sampled multiple times over the 
seven and one quarter years. MSHA found 29 mines with at least one 
miner exposed to an equivalent 8-hour TWA (SWA) fiber concentration 
exceeding 0.1 f/cc. Out of a total of 917 SWA personal full-shift fiber 
exposure sample results, 113 (12 percent) exceeded 0.1 f/cc using the 
existing PCM-based analytical screening method.
    Further analysis of the 113 samples with TEM confirmed asbestos 
fiber exposures exceeding 0.1 f/cc in 23 of them. Using the existing 
TEM-based analytical method, 3 percent of the total number of SWA 
samples taken exceeded 0.1 asbestos f/cc. Five mines (two taconite, one 
wollastonite, one sand and gravel, and one olivine), out of the 29 
mines potentially impacted by lowering the PEL, had at least one miner 
with an SWA asbestos fiber exposure exceeding 0.1 f/cc. Although MSHA 
has no evidence of asbestos exposure above the new PEL in coal mines, 
the Agency anticipates that some coal mines will encounter asbestos 
from asbestos containing materials (ACM) brought onto mine property. 
These operators may have to take corrective action. Table III-1 below 
summarizes MSHA's asbestos sampling results for the period January 2000 
through May 2007.

                        Table III-1.--Personal Exposure Samples at Mines \1\ by Commodity
                                                 [1/2000-5/2007]
----------------------------------------------------------------------------------------------------------------
                                                     Number (%) of                                   Number (%)
                                       Number of    mines with SWA    Number of     Number (%) of      of SWA
              Commodity                  mines     samples >0.1  f/      SWA      SWA samples >0.1  samples >0.1
                                        sampled        cc by PCM       samples     f/cc by PCM \2\   f/cc by TEM
----------------------------------------------------------------------------------------------------------------
Rock & quarry products \3\..........          127           11 (9%)          326           20 (6%)        2 (1%)
Vermiculite.........................            4           3 (75%)          149           13 (9%)            0
Wollastonite........................            1          1 (100%)           18         18 (100%)       9 (50%)
Iron (taconite).....................           15           5 (33%)          254          43 (17%)       11 (4%)
Talc................................           12            1 (8%)           38            2 (5%)            0
Alumina \4\.........................            1                0             1                0             0
Feldspar............................            7                0         \5\ 6                0             0
Boron...............................            2           1 (50%)           12           7 (58%)            0
Olivine.............................            2          2 (100%)            9           3 (33%)       1 (11%)
Other \6\...........................           36       \7\ 5 (14%)          104            7 (6%)            0
                                     ---------------------------------------------------------------------------
    TOTAL...........................          207      \8\ 29 (14%)          917         113 (12%)       23 (3%) 
----------------------------------------------------------------------------------------------------------------
\1\ Excludes data from an asbestos mine and mill closed in 2003.
\2\ MSHA uses TEM to identify asbestos on samples with results exceeding 0.1 f/cc.
\3\ Including stone, and sand and gravel mines.
\4\ 15-minute sample.
\5\ Incomplete SWA at one mine.
\6\ Coal, potash, gypsum, cement, perlite, clay, lime, mica, metal ore NOS, shale, pumice, trona, salt, gold,
  and copper.
\7\ Coal, potash, gypsum, cement, and perlite. (Coal and potash exposures were due to fiber release episodes
  from commercially introduced asbestos).
\8\ TEM confirmed airborne asbestos exposures exceeding 0.1 f/cc at five (2%) mines.


[[Page 11289]]

    The USGS has published a series of maps showing historic asbestos 
prospects and natural asbestos occurrences in the United States. The 
USGS published a map covering the eastern states in 2005; the central 
states in 2006; and the Rocky Mountain states in 2007. These maps 
served as a guide for the investigation of possible naturally occurring 
asbestos within the vicinity of mining operations. MSHA found that 
stone mines and quarries are the predominate types of mining operations 
in the vicinity of naturally occurring asbestos locations identified on 
the maps. MSHA conducted fiber sampling at these mines to screen for 
potential asbestos exposures. The results of the sampling indicated a 
small degree of asbestos at some of these mining operations, but no 
widespread asbestos contamination. Although not included on the USGS 
maps, MSHA also surveyed two mines in El Dorado County, California. 
Sampling at one of the mines resulted in two personal asbestos 
exposures greater than 0.1 f/cc, confirmed by TEM analysis, and 2 to 5 
percent naturally occurring asbestos in an associated bulk sample. Air 
sampling at the other mine had low PCM fiber results.

D. Asbestos Take-Home Contamination

    The final rule, like the proposal, does not address take-home 
contamination. In making this decision, MSHA considered its enforcement 
experience; comments and testimony on the proposal; as well as OSHA, 
NIOSH, and EPA publications and experience.\39\ MSHA based its 
determination to address asbestos take-home contamination, without 
promulgating new regulatory provisions, on the following factors:
---------------------------------------------------------------------------

    \39\ NIOSH (Report to Congress) September 1995.
---------------------------------------------------------------------------

     There are no asbestos mines or mills currently operating 
in this country and different ore bodies of the same commodity, such as 
vermiculite mining, are not consistent in the presence, amount, or 
dispersion of asbestiform minerals. Based on MSHA's recent enforcement 
sampling, asbestos exposures in mining are low. (See Table III-1.)
     The measures taken to prevent take-home contamination are 
varied. Operators may choose the most effective method for eliminating 
this hazard based on the unique conditions in the mine, including the 
nature of the hazard. For example, in one situation providing 
disposable coveralls could minimize or prevent asbestos take-home 
contamination. Another situation may require on-site shower facilities 
coupled with clothing changes to provide the same protection.
     Existing standards (e.g., personal protection Sec. Sec.  
56/57.15006; sanitation Sec. Sec.  56/57.20008, 56/57.20014, 71.400, 
71.402; housekeeping Sec. Sec.  56/57.16003, 56/57.20003, 77.208; 
appropriate actions Sec. Sec.  56/57.18002, 56/57.20011, 77.1713; 
hazard communication 30 CFR 46, 47, and 48), together with lower PELs, 
provide sufficient enforcement authority to ensure that mine operators 
take adequate measures when necessary to prevent asbestos take-home 
contamination.
    Commenters urged MSHA to expand the rulemaking to include specific 
requirements to prevent take-home contamination. NIOSH also encouraged 
MSHA to adopt measures included in its 1995 Report to Congress on their 
Workers' Home Contamination Study Conducted under the Workers' Family 
Protection Act. Other commenters, however, supported MSHA's decision 
and stated that take-home contamination requirements could not be 
justified at this time.

IV. Application of OSHA's Risk Assessment to Mining

    MSHA has determined that OSHA's 1986 asbestos risk assessment (51 
FR 22644) is applicable to asbestos exposures in mining. In developing 
this final rule, MSHA also evaluated studies published since OSHA 
completed its 1986 risk assessment, and studies that specifically 
focused on asbestos exposures of miners. These additional studies 
corroborate OSHA's conclusions in its risk assessment.

A. Summary of OSHA's Risk Assessment

1. Cancer Mortality
    In its 1986 risk assessment, OSHA estimated cancer mortality for 
workers exposed to asbestos at various cumulative exposures (i.e., 
combining exposure concentration and duration of exposure). MSHA has 
reproduced this data in Table IV-1. Table IV-1 shows that the estimated 
mortality from asbestos-related cancer decreases significantly by 
lowering exposure. This is true regardless of the type of cancer, e.g., 
lung, pleural or peritoneal mesotheliomas, or gastrointestinal. 
Although excess relative risk is linear in dose, the excess mortality 
rates in Table IV-1 are not.\40\
---------------------------------------------------------------------------

    \40\ Nicholson, p. 53, 1983.

  Table IV-1.--Estimated Asbestos-Related Cancer Mortality per 100,000 by Number of Years Exposed and Exposure
                                                      Level
----------------------------------------------------------------------------------------------------------------
                                                              Cancer mortality per 100,000 exposed
      Asbestos fiber concentration (f/cc)      -----------------------------------------------------------------
                                                     Lung        Mesothelioma   Gastrointestinal       Total
----------------------------------------------------------------------------------------------------------------
                                                 1-year exposure
----------------------------------------------------------------------------------------------------------------
0.1...........................................             7.2             6.9              0.7             14.8
0.2...........................................            14.4            13.8              1.4             29.6
0.5...........................................            36.1            34.6              3.6             74.3
2.0...........................................             144             138             14.4            296.4
4.0...........................................             288             275             28.8            591.8
5.0...........................................             360             344             36.0           740.0
10.0..........................................             715             684             71.5          1,470.5
----------------------------------------------------------------------------------------------------------------
                                                20-year exposure
----------------------------------------------------------------------------------------------------------------
0.1...........................................             139              73             13.9            225.9
0.2...........................................             278             146             27.8            451.8
0.5...........................................             692             362             69.2          1,123.2
2.0...........................................           2,713           1,408            271.3          4,392.3
4.0...........................................           5,278           2,706            527.8          8,511.8

[[Page 11290]]

 
5.0...........................................           6,509           3,317            650.9        10,476.9
10.0..........................................          12,177           6,024          1,217.7         13,996.7
----------------------------------------------------------------------------------------------------------------
                                                45-year exposure
----------------------------------------------------------------------------------------------------------------
0.1...........................................             231              82             23.1            336.1
0.2...........................................             460             164             46.0            670.0
0.5...........................................           1,143             407            114.3          1,664.3
2.0...........................................           4,416           1,554            441.6          6,411.6
4.0...........................................           8,441           2,924            844.1         12,209.1
5.0...........................................          10,318           3,547          1,031.8         14,896.8
10.0..........................................          18,515           6,141          1,851.5         26,507.5
----------------------------------------------------------------------------------------------------------------

    Table IV-1 shows that, by lowering the PEL from 2 f/cc to 0.1 f/cc, 
the risk of cancer mortality drops 95 percent from an estimated 6,411 
to 336 deaths (per 100,000 workers).
2. Asbestosis
    Finkelstein (1982) studied a group of 201 men who worked in a 
factory in Ontario, Canada, that manufactured asbestos-cement pipe and 
rock-wool insulation. Finkelstein demonstrated that there was a 
relationship between cumulative asbestos exposure and confirmed 
asbestosis.
    Berry and Lewinsohn (1979) studied a group of 379 men who worked in 
an asbestos textile factory in northern England. Berry and Lewinsohn 
(1979) defined two different cohorts: Men who were first employed 
before 1951, when asbestos fiber levels were estimated; and men first 
employed after 1950, when asbestos fiber levels were measured. They 
plotted cases of possible asbestosis to determine a dose response 
curve.
    OSHA stated that ``* * * the best estimates of asbestosis incidence 
are derived from the Finkelstein data * * *'' (48 FR 51132). OSHA did 
not rely on the values for the slope as determined by Berry and 
Lewinsohn (1979). Based on Finkelstein's (1982) linear relationship for 
lifetime asbestosis incidence, OSHA calculated estimates of lifetime 
asbestosis incidence at five exposure levels of asbestos (i.e., 0.5, 1, 
2, 5, and 10 f/cc) and published its estimate in tabular form (48 FR 
51132). MSHA has reproduced OSHA's estimates in Table IV-2 below. OSHA 
stated (51 FR 22646) that ``Reducing the exposure to 0.2 f/cc, a 
concentration not included in Table IV-2, would result in a lifetime 
incidence of asbestosis of 0.5%.''
---------------------------------------------------------------------------

    \41\ Finkelstein, 1982; Berry and Lewinsohn, 1979.

                          Table IV-2.--Estimates of Lifetime Asbestosis Incidence \41\
----------------------------------------------------------------------------------------------------------------
                                                                 Percent (%) Incidence
                                      --------------------------------------------------------------------------
         Exposure level, f/cc                                                              Berry and Lewinsohn
                                             Finkelstein          Berry and Lewinsohn     (first employed after
                                                                 (employed before 1951)           1950)
----------------------------------------------------------------------------------------------------------------
0.5..................................                    1.24                     0.45                     0.35
1....................................                    2.49                     0.89                     0.69
2....................................                    4.97                     1.79                     1.38
5....................................                   12.43                     4.46                   * 3.45
10...................................                   24.86                     8.93                     6.93
Slope................................                    0.055                    0.020                    0.015
R \2\................................                    0.975                    0.901                    0.994 
----------------------------------------------------------------------------------------------------------------
* Note: 1.38 in original table was a typographical error. The text (48 FR 51132) and the regression formula
  indicate that 3.45 is the correct percent.

    Similar to the cancer risk, Table IV-2 shows a significant 
reduction in the incidence of asbestosis by lowering asbestos 
exposures. MSHA calculated the incidence of asbestosis following 45 
years of exposure to asbestos at a concentration of 0.1 f/cc, which 
OSHA had not included in Table IV-1, to be 0.25 percent or 250 cases 
per 100,000 workers. Thus, by lowering the 8-hour TWA PEL from 2 f/cc 
to 0.1 f/cc, MSHA will reduce the lifetime asbestosis risk by 95 
percent from an estimated 4,970 cases to 250 cases (per 100,000 
workers).

B. Risk Assessment for the Mining Industry

    OSHA stated in the preamble to its 1986 asbestos rule that it 
excluded mining studies in its risk assessment because it believed that 
risks in the asbestos mining-milling operations are lower than other 
industrial operations due to differences in fiber size (51 FR 22637). 
MSHA reviewed the studies OSHA used to develop its risk assessment.\42\ 
In addition, MSHA obtained and reviewed the latest available scientific 
studies on the health

[[Page 11291]]

effects of asbestos exposure. MSHA recognizes that there are 
uncertainties in any risk assessment. MSHA concluded, however, that 
these studies provide further support of the significant risk of 
adverse health effects following exposure to asbestos.
---------------------------------------------------------------------------

    \42\ Berry and Newhouse, 1983; Dement et al., 1982; Finkelstein, 
1983; Henderson and Enterline, 1979; Peto, 1980; Peto et al., 1982; 
Seidman et al., 1979; Seidman, 1984; Selikoff et al., 1979; Weill et 
al., 1979.
---------------------------------------------------------------------------

    MSHA reviewed the mining studies described in OSHA's asbestos risk 
assessment, as well as other studies that involved the exposure of 
miners to asbestos. Most of these studies were conducted in Canada, 
although some have been conducted in Australia, India, Italy, South 
Africa, and the United States. Table IV-3 lists some of these mining 
studies, in chronological order, and gives the salient features of each 
study. These studies are in MSHA's rulemaking docket.

    Table IV.-3--Selected Studies Involving Miners Exposed to Asbestos
------------------------------------------------------------------------
                                Study group, type   Major finding(s) or
Author(s), year of publication     of asbestos         conclusion(s)
------------------------------------------------------------------------
Rossiter et al., 1972.........  Canadian miners    Radiographic changes
                                 and millers,       (opacities) related
                                 Chrysotile.        to age and exposure.
Becklake, 1979................  Canadian miners    Weak relationship
                                 and millers,       between exposure and
                                 Chrysotile.        disease.
Gibbs and du Toit, 1979.......  Canadian and       Need for workplace
                                 South African      epidemiologic
                                 miners,            surveillance and
                                 Chrysotile.        environmental
                                                    programs.
Irwig et al., 1979............  South African      Parenchymal
                                 miners, Amosite    radiographic
                                 and Crocidolite.   abnormalities
                                                    preventable by
                                                    reduced exposure.
McDonald and Liddell, 1979....  Canadian miners    Lower risk of
                                 and millers,       mesotheliomas and
                                 Chrysotile.        lung cancer from
                                                    chrysotile than
                                                    crocidolite.
Nicholson et al., 1979........  Canadian miners    Miners and millers:
                                 and millers,       at lower risk of
                                 Chrysotile.        mesotheliomas, at
                                                    risk of asbestosis
                                                    (as factory workers
                                                    and insulators), at
                                                    risk of lung cancer
                                                    (as factory
                                                    workers).
Rubino et al., Ann NY Ac Sci    Italian miners,    Role of individual
 1979.                           Chrysotile.        susceptibility in
                                                    appearance and
                                                    progression of
                                                    asbestosis.
Rubino et al., Br J Ind Med     Italian miners,    Elevated risk of lung
 1979.                           Chrysotile.        cancer.
Solomon et al., 1979..........  South African      Sign of exposure to
                                 miners, Amosite    asbestos: thickened
                                 and Crocidolite.   interlobar fissures.
McDonald et al., 1980.........  Canadian miners    No statistically
                                 and millers,       significant
                                 Chrysotile.        increases in SMRs.
McDonald et al., 1986.........  U.S. miners,       A. Increased risk of
                                 Tremolite..        mortality from
                                                    respiratory cancer.
McDonald et al., 1986.........  U.S. miners,       B. Increased
                                 Tremolite.         prevalence of small
                                                    opacities by
                                                    retirement age.
Cookson et al., 1986..........  Australian miners  No threshold dose for
                                 and millers,       development of
                                 Crocidolite.       radiographic
                                                    abnormality.
Amandus et al., 1987..........  U.S. miners and    Part I: Exposures
                                 millers,           below 1 f/cc after
                                 Tremolite-         1977, up to 100-200
                                 Actinolite.        x higher in 1960's
                                                    and 1970's.
Amandus and Wheeler, 1987.....  U.S. miners and    Part II: Increased
                                 millers,           mortality from
                                 Tremolite-         nonmalignant
                                 Actinolite.        respiratory disease
                                                    and lung cancer.
Amandus et al., 1987..........  U.S. miners and    Part III: Increased
                                 millers,           prevalence of
                                 Tremolite-         radiographic
                                 Actinolite.        abnormalities
                                                    associated with past
                                                    exposure.
Armstrong et al., 1988........  Australian miners  Increased mortality
                                 and millers,       from mesotheliomas
                                 Crocidolite.       and lung cancer.
Enarson et al., 1988..........  Canadian miners,   Increased cough,
                                 Chrysotile.        breathlessness,
                                                    abnormal lung volume
                                                    and capacity.
McDonald et al., 1988.........  U.S. miners and    Low exposure and no
                                 millers,           statistically
                                 Tremolite.         significant SMRs.
McDonald et al., 1993.........  Canadian miners    Increased SMRs for
                                 and millers,       lung cancer and
                                 Chrysotile.        mesotheliomas as
                                                    cohort aged.
Dave et al., 1996.............  Indian miners and  Higher exposures in
                                 millers,           surface than
                                 Chrysotile.        underground mines;
                                                    higher exposures in
                                                    mills than mines;
                                                    restrictive lung
                                                    impairment and
                                                    radiologic
                                                    parenchymal changes
                                                    more common in
                                                    millers.
McDonald et al., 1997.........  Canadian miners    Risk of mesotheliomas
                                 and millers,       related to geography
                                 Chrysotile.        and mineralogy of
                                                    region;
                                                    mesotheliomas caused
                                                    by amphiboles.
Nayebzadeh et al., 2001.......  Canadian miners    Respiratory disease
                                 and millers,       related to regional
                                 Chrysotile.        differences in fiber
                                                    concentration and
                                                    not dimension.
Ramanathan and Subramanian,     Indian miners and  Increased risk of
 2001.                           millers,           cancer, restrictive
                                 Chrysotile and     lung disease,
                                 tremolite.         radiologic changes,
                                                    and breathing
                                                    difficulties; more
                                                    common in milling.
Bagatin et al., 2005..........  Brazilian miners   Decreased risk of non-
                                 and millers,       malignant
                                 Chrysotile.        abnormalities with
                                                    improvements in
                                                    workplace
                                                    conditions.
Nayebzadeh et al., 2006.......  Canadian miners    Possible use of lung
                                 and millers,       fiber concentration,
                                 Chrysotile,        especially short
                                 Tremolite,         tremolite fibers, to
                                 Amosite.           predict fibrosis
                                                    grade.
Sullivan, 2007................  U.S. miners,       Increased mortality
                                 millers, and       from asbestosis,
                                 processors,        cancer of the
                                 Tremolite.         pleura, and lung
                                                    cancer that were
                                                    dose-related.
------------------------------------------------------------------------

    MSHA found that many of the observations presented in these mining 
studies (e.g., age of first exposure, latency, radiologic changes) are 
consistent with those from the studies OSHA relied on in its risk 
assessment, as well as studies of other asbestos-exposed factory and 
insulation workers. MSHA concludes that exposure to asbestos, a known 
human carcinogen, results in similar disease endpoints regardless of 
the occupation that has been studied. Because there is evidence of 
asbestos-related disease among miners, MSHA is applying the OSHA risk 
assessment to the mining industry.
    Some commenters stated that there is a differential health risk 
related to fiber type and that OSHA's risk assessment is not adequate 
or appropriate for the mining industry. The OSHA risk assessment 
addresses adverse health effects from exposure to six asbestos 
minerals. MSHA applies TEM analysis

[[Page 11292]]

to its PCM results to determine exposure to these same six asbestos 
minerals. Exposure of miners to these asbestos minerals, at the same 
concentrations and length of exposures as workers in other industries, 
can be expected to result in the same disease endpoints as quantified 
in OSHA's risk assessment. (See section II.C and II.D of this preamble 
and chapter III of the REA.)
    Some commenters also expressed concern regarding the health risks 
of fibrous minerals that are not currently regulated under MSHA's 
existing standards and suggested that MSHA conduct a new risk 
assessment to include them. MSHA considered these comments and 
determined that a new risk assessment is not necessary for this final 
rule, since fibrous minerals that are not currently regulated under 
MSHA's existing standards are beyond the scope of this rulemaking.
    Some commenters stressed the lack of asbestos-related disease among 
miners in studies conducted at gold, taconite, and talc operations 
where there was asbestos contamination in the ore. In developing this 
final rule, MSHA considered a number of environmental and 
epidemiological studies conducted at mining operations. These studies 
demonstrated adverse health effects among miners consistent with 
exposure to asbestos in other workers. Researchers have found excessive 
incidence of asbestos-related disease in miners at a vermiculite mining 
operation.\43\ Studies of talc miners have shown excess lung cancer and 
non-malignant respiratory disease.\44\ Researchers are now studying 
excessive mesotheliomas among iron miners in northeastern Minnesota to 
determine the source of the asbestos exposure.
---------------------------------------------------------------------------

    \43\ Sullivan, 2007.
    \44\ NIOSH (HETA/MHETA), 1990; NIOSH (Technical Report), 1980.
---------------------------------------------------------------------------

    Section VI of this preamble contains a summary of MSHA's findings 
from applying OSHA's quantitative assessment of risk to the mining 
industry. MSHA's Regulatory Economic Analysis (REA) contains a more in-
depth discussion of the Agency's methodology and conclusions. MSHA 
placed the REA in the rulemaking docket and posted it on the Asbestos 
Single Source Page at http://www.msha.gov/asbestos/asbestos.htm. MSHA 
also placed OSHA's risk assessment in its rulemaking docket.

C. Characterization of the Risk to Miners

    After reviewing the evidence of adverse health effects associated 
with exposure to asbestos, MSHA evaluated that evidence to ascertain 
whether exposure levels currently existing in mines warrant regulatory 
action. The criteria for this evaluation are established by the Federal 
Mine Safety and Health Act of 1977 (Mine Act) and related court 
decisions.\45\
---------------------------------------------------------------------------

    \45\ Industrial Union Department, AFL-CIO v. American Petroleum 
Institute, 448 U.S. 607, 100 S.Ct. 2844 (1980) (``Benzene case'')
---------------------------------------------------------------------------

    Section 101(a) of the Mine Act requires MSHA `` * * * to develop, 
promulgate, and revise * * * improved mandatory health or safety 
standards for the protection of life and prevention of injuries in coal 
or other mines.'' Further, section 101(a)(6)(A) 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.

    Section 101(a)(6)(A) also requires that MSHA base its health and 
safety standards on ``* * * the latest available scientific data in the 
field, the feasibility of the standards, and experience gained under 
this and other health and safety laws.'' As discussed in section VI.B, 
a 0.1 f/cc TWA PEL for asbestos is technologically and economically 
feasible.
    Based on court interpretations of similar language under the 
Occupational Safety and Health Act, MSHA has addressed the following 
three questions:
    (1) Do the health effects associated with asbestos exposure 
constitute a ``material impairment'' to miner health or functional 
capacity? Miners exposed to asbestos are at risk of developing lung 
cancer, mesotheliomas, and other cancers, as well as asbestosis and 
other nonmalignant respiratory diseases.\46\ These health effects 
constitute a ``material impairment of health or functional capacity.''
---------------------------------------------------------------------------

    \46\ American Thoracic Society, 2004; Delpierre et al., 2002.
---------------------------------------------------------------------------

    (2) Are exposed miners at significant risk of incurring any of 
these material impairments? Based on OSHA's risk assessment, MSHA has 
determined that a significant health risk exists for miners exposed to 
asbestos at MSHA's existing 8-hour TWA PEL of 2 f/cc. Over a 45-year 
working life, exposure at this level can be expected to result in a 6.4 
percent incidence of cancer (lung cancer, mesotheliomas, and 
gastrointestinal cancer) and a 5.0 percent incidence of asbestosis.
    (3) Will this final rule substantially reduce such risks? By 
lowering the 8-hour TWA PEL to 0.1 f/cc, MSHA will reduce the risk of 
asbestos-related cancers from 6.4 percent to 0.34 percent and the risk 
of asbestosis from 5.0 percent to 0.25 percent. MSHA considers this 
reduction to be substantial.

V. Section-by-Section Analysis of Final Rule

    The final rule is substantively the same as the proposed rule. To 
make the standard easier to read, however, MSHA has divided the 
requirements in the final standards into three paragraphs: Definitions, 
Permissible Exposure Limits (PELs), and Measurement of Airborne Fiber 
Concentration. For Sec. Sec.  56/57.5001(b), the metal and nonmetal 
asbestos standards, MSHA designated the paragraphs (b)(1), (b)(2), and 
(b)(3). For Sec.  71.702, the coal asbestos standard, MSHA designated 
the paragraphs (a), (b), and (c).

A. Sec. Sec.  56/57.5001(b)(1) and 71.702(a): Definitions

    The final rule, like the proposal, makes no substantive changes to 
the definition of asbestos in MSHA's existing standards. MSHA's 
existing definition of asbestos is consistent with the regulatory 
provisions of several Federal agencies including EPA, OSHA, and CPSC, 
among others. Asbestos is not a definitive mineral, but rather a 
generic name for a group of minerals with specific characteristics. 
MSHA's existing standards state that, ``when crushed or processed, 
[asbestos] separates into flexible fibers made up of fibrils'' 
[Sec. Sec.  56/57.5001(b)]; and ``does not include nonfibrous or 
nonasbestiform minerals'' (Sec.  71.702). Although there are many 
asbestiform minerals,\47\ the term asbestos in MSHA's existing 
standards and this final rule is limited to the following six: \48\
---------------------------------------------------------------------------

    \47\ Leake et al., 1997; Meeker et al., 2003.
    \48\ ATSDR, p.136, 2001; NIOSH Pocket Guide, 2003.
---------------------------------------------------------------------------

     Chrysotile (serpentine asbestos, white asbestos).
     Cummingtonite-grunerite asbestos (amosite, brown 
asbestos).
     Crocidolite (riebeckite asbestos, blue asbestos).
     Anthophylite asbestos (asbestiform anthophyllite).
     Tremolite asbestos (asbestiform tremolite).
     Actinolite asbestos (asbestiform actinolite).
    Like the proposal, the final rule makes several clarifying changes 
to the existing regulatory language. They have no impact on the 
minerals that MSHA regulates as asbestos. This more precise

[[Page 11293]]

language will facilitate mine operators' understanding of the scope of 
the standard. This final asbestos rule--
     Clarifies that cummingtonite-grunerite asbestos is the 
mineralogical term for amosite, a trade name for asbestos from a 
specific geographical region;
     Clarifies that MSHA's definition of fiber for analytical 
purposes includes the same dimensional criteria as in the existing 
standards, which are consistent with OSHA's asbestos standard; and
     Clarifies the asbestos standard by inserting uniform 
structure and language.
    Some commenters suggested that MSHA should expand its definition of 
asbestos to include other asbestiform minerals, so long as MSHA's 
analytical method excluded the counting of cleavage fragments. Another 
commenter asked that MSHA not include nonasbestiform fibrous minerals 
and mineral cleavage fragments when MSHA performs microscopic analyses 
of samples. Others supported the inclusion and regulation of 
asbestiform amphiboles that have shown or are likely to show asbestos-
like health effects.
    Many commenters did not want MSHA to make changes to the fibers 
regulated as asbestos in the existing standards. Specifically, they did 
not want MSHA to address other asbestiform amphiboles found in mineral 
deposits because there is no evidence that these fibers pose the same 
health problems that asbestos does. Some said that it would be 
unreasonable and expensive to try to meet exposure limits for all these 
other asbestiform minerals. Other commenters stated that, whatever they 
are called, asbestiform minerals cause illness.
    As stated throughout this rulemaking, the final rule makes no 
substantive changes to the definition of asbestos in MSHA's existing 
standards. Such changes were not contemplated in the proposed rule and, 
therefore, are beyond the scope of this final rule.

B. Sections 56/57.5001(b)(2) and 71.702(b): Permissible Exposure Limits 
(PELs)

1. Sections 56/57.5001(b)(2)(i) and 71.702(b)(1): 8-Hour, Time-Weighted 
Average (TWA), Full-Shift Permissible Exposure Limit
    The final rule adopts OSHA's 8-hour TWA PEL of 0.1 f/cc. No 
commenters objected to this aspect of the proposal.
    Asbestos occurs naturally in many types of ore bodies and may be 
released from mine sites into the environment; but, MSHA's sampling 
results indicate that there is not widespread overexposure to asbestos 
in the mining industry at this time. MSHA's sampling data for 2000 
through May 2007 show that 3 percent of MSHA's full-shift asbestos 
samples exceed OSHA's TWA PEL of 0.1 f/cc using a TEM-based analysis.
    Commenters expressed concern about potential asbestos exposure of 
those living close to a mining operation. Although MSHA's reduction of 
its asbestos PELs may reduce environmental levels, other Federal, 
State, and local agencies have jurisdiction over environmental 
exposures.
2. Sections 56/57.5001(b)(2)(ii) and 71.702(b)(2): Excursion Limit
    The final rule, like the proposal, adopts OSHA's excursion PEL of 1 
f/cc as measured over 30 minutes. Some commenters were concerned that 
an excursion limit is not enforceable and, therefore, should be removed 
from the rule. Although MSHA may not always be present to take air 
samples to evaluate a miner's exposure during brief episodes of 
asbestos exposure, existing Sec. Sec.  56/57.5002 and 71.701 require 
mine operators to conduct sampling to determine the need for, and 
effectiveness of, control measures when miners may be exposed to 
asbestos.
    An excursion limit sets levels, not based on toxicological data, 
for peak episodes of exposure. As previously discussed, asbestos poses 
a long-term health risk to exposed workers. Although the final rule 
will substantially reduce the risk of asbestos-related deaths from a 
lifetime exposure, it does not completely eliminate this risk. The 
excursion limit will help reduce the long-term risk by addressing 
brief, episodic exposures. This type of episodic exposure can be 
foreseen and proactively controlled by the use of personal protective 
equipment (respirators and protective clothing) and by implementing 
engineering or work practice controls (glove boxes, tents, wet 
methods).
    The final rule includes an excursion limit for asbestos to help 
maintain the average airborne concentration below the full-shift 
exposure limit. For example, for miners exposed to one 30-minute 
excursion per day at 1 f/cc, the 8-hour TWA airborne asbestos 
concentration would be 0.06 f/cc, which is less than the 0.1 f/cc 8-
hour TWA PEL. For miners exposed to two 30-minute excursions per day at 
1 f/cc, the 8-hour TWA airborne asbestos concentration would be 0.13 f/
cc, which exceeds the 0.1 f/cc 8-hour TWA PEL.
    One commenter urged MSHA to retain 15 minutes, rather than switch 
to 30 minutes, as the sampling period for enforcement of the excursion 
limit. As shown in Table V-1 below, the excursion limit of 1 f/cc for 
30 minutes is the lowest concentration that MSHA can measure reliably 
for determining compliance with the excursion limit. MSHA recognizes 
that in some situations, such as low background dust levels, lower 
exposures could be measured by using a higher flow rate; but, the risk 
of overloading the filter with debris increases when using higher flow 
rates. MSHA can be confident that it is measuring the actual airborne 
concentrations of asbestos, within a standard sampling and analytical 
error (25 percent), when the Agency uses the minimum 
loading suggested by the OSHA Reference Method (29 CFR 1910.1001, 
Appendix A).
    As discussed in OSHA's 1986 asbestos final rule (51 FR 22686), the 
key factor in sampling precision is fiber loading. To determine whether 
the analytical method described in Appendix A of its asbestos standard 
could be used to analyze short-term samples, OSHA calculated the lowest 
reliable limit of quantification using the following formula:

    C = [(f/[(n)(Af)])(Ac)]/[(V)(1,000)]

Where:

C = fiber concentration (in f/cc of air);
f = the total fiber count;
n = the number of microscope fields examined;
Af = the field area (0.00785 mm2) for a 
properly calibrated Walton-Beckett graticule;
Ac = the effective area of the filter (in 
mm2); and
V = the sample volume (liters).

    Table V-1 was generated from the above equation. The table shows 
that 1 f/cc measured over 30 minutes can be reliably measured when 
pumps are used at the higher flow rates of 1.6 Lpm or more, using 25-mm 
filters. The table also shows that MSHA cannot reliably measure 1 f/cc 
with 15-minute air samples, even when they are collected at the higher 
pump flow rates.

[[Page 11294]]



 Table V-1.--Relationship of Sampling Method to Measurement of Asbestos
------------------------------------------------------------------------
                                                Lowest level reliably
        Sampling time and flow rate              measured using 25-mm
                                                       filters
------------------------------------------------------------------------
15 min at 2.5 Lpm..........................  1.05 f/cc.
15 min at 2.0 Lpm..........................  1.31 f/cc.
15 min at 1.6 Lpm..........................  1.63 f/cc.
15 min at 1.0 Lpm..........................  2.61 f/cc.
15 min at 0.5 Lpm..........................  5.23 f/cc.
30 min at 2.5 Lpm..........................  0.51 f/cc.
30 min at 2.0 Lpm..........................  0.65 f/cc.
30 min at 1.6 Lpm..........................  0.82 f/cc.
30 min at 1.0 Lpm..........................  1.31 f/cc.
30 min at 0.5 Lpm..........................  2.61 f/cc.
------------------------------------------------------------------------

    After evaluating the comments, MSHA retains the proposed asbestos 
excursion limit of 1 f/cc over a period of 30 minutes in the final 
rule.

C. Sections 56/57.5001(b)(3) and 71.702(c): Measurement of Airborne 
Fiber Concentrations

    The final rule, like the proposed rule, requires an initial 
determination of fiber concentration using a PCM-based analytical 
method statistically equivalent to the OSHA Reference Method in OSHA's 
asbestos standard (29 CFR 1910.1001, Appendix A).
    With respect to analytical methods, the final rule is substantively 
the same as MSHA's existing standards. PCM-based analytical methods 
were used in the development of past exposure assessments and risk 
estimates, and are relatively quick and cost-effective. OSHA used a 
PCM-based methodology as the defining basis of its asbestos risk 
assessment. PCM-based analytical methods remain the most practical way 
to evaluate asbestos exposures in mining. MSHA recognizes, however, 
that all analytical methods, including those used to identify and 
quantify the six asbestos minerals regulated by MSHA have limitations. 
Analysts have quantified the limits of detection, precision, and 
accuracy of these methods, termed ``analytical error;'' and MSHA 
includes this analytical error in evaluating asbestos exposures and 
enforcing the PELs. As discussed below, comments varied on MSHA's 
proposed sampling and analytical techniques. Most commenters supported 
a combination of PCM-based and TEM-based techniques for evaluating mine 
air samples.
1. Background of Analytical Method for Asbestos
    Historically, asbestos samples have been analyzed by mass 
(weighing), counting (microscopy), or a qualitative property 
(spectroscopy). When recommending an exposure standard for chrysotile 
asbestos, the British Occupational Hygiene Society said \49\ that the 
microscopic counting of particles greater than 5 [mu]m in length would 
show a relationship with the prevalence of asbestosis similar to those 
studies based on the mass of respirable asbestos. Many studies have 
suggested that counting only fibers longer than 5 [mu]m minimizes 
variations between microscopy techniques \50\ and improves the 
precision of the results.\51\ The scientific community accepted this 
length together with a minimum 3:1 length to diameter aspect ratio, as 
the counting criteria for asbestos fibers that provides an index of 
asbestos exposure, even though some believed that shorter fibers should 
be included due to their possible health effects.\52\ Acceptance of 
PCM-based methodology has served as the basis of asbestos risk 
assessments.
---------------------------------------------------------------------------

    \49\ Lane et al., 1968.
    \50\ ACGIH-AIHA, 1975.
    \51\ Wylie, 2000.
    \52\ ACGIH-AIHA, 1975; NIOSH, 1972.
---------------------------------------------------------------------------

    In recommending an asbestos standard in 1972 and 1976, NIOSH 
suggested using the same size criteria that the British adopted. They 
also recommended reevaluating these criteria when more definitive 
information on the biologic response and precise epidemiologic data are 
developed. NIOSH applied a conversion factor to exposure data not 
obtained using a PCM-based analytical method, to estimate what the 
exposure data would have been using a PCM-based method. This conversion 
allowed NIOSH to use non-PCM-based exposure data, together with PCM-
based exposure data, in determining a recommended permissible exposure 
level.
2. MSHA's Analytical Methods for Enforcement of Its Asbestos PELs
    Prior to 2001, OSHA analyzed MSHA's asbestos samples using OSHA ID-
160, a PCM-based analytical method. Since 2001, MSHA has contracted 
with American Industrial Hygiene Association (AIHA) accredited 
laboratories to analyze its asbestos samples using NIOSH's PCM-based 
analytical method, and to follow up with an analysis using NIOSH's TEM-
based method when the PCM results indicate an exposure exceeding 0.1 f/
cc. These commercial laboratories report analytical results as the 
fiber concentration (f/cc) for each filter analyzed.
    Several factors complicate the evaluation of personal exposure 
levels in mining environments. For example, non-asbestos fibers and 
dust particles collected on the filter can obscure the asbestos fibers 
or overload the filter. Depending on the amount of visible dust in the 
air, MSHA's sampling procedures allow the setting of pump flow rates 
and consecutive sampling to minimize or eliminate mixed dust overload.
    Commenters criticized MSHA's use of PCM-based methods to evaluate 
asbestos exposures. Several recommended that MSHA adopt a new ASTM 
method (ASTM D 7200-06), which references the characteristics of 
asbestiform fibers in EPA's bulk sample method.\53\ Many recommended 
that MSHA not conduct air sampling unless prior bulk sampling had 
identified asbestos fibers. Some commenters recommended that the final 
rule include a TEM-based analytical method for the initial 
determination of compliance.
---------------------------------------------------------------------------

    \53\ ASTM, 2006; EPA, 1993.
---------------------------------------------------------------------------

    Bulk sampling presents limitations. The presence of asbestos in a 
bulk sample does not mean that it poses a hazard. The asbestos must 
become airborne and be respirable, or contaminate food or water, to 
pose a health hazard to miners. Analysis of bulk samples is usually 
performed using polarized light microscopy (PLM). A particle must be at 
least 0.5 [mu]m in diameter to refract light and many asbestos fibers 
are too thin to refract light. Asbestos may be a small percentage of 
the parent material or not uniformly dispersed in the sample and,

[[Page 11295]]

therefore, may not be seen in the small portion of sample that is 
examined under the microscope. Another problem with identifying 
asbestos using PLM is that both the asbestiform and nonasbestiform 
varieties of a mineral show the same refractive index. Although a 
trained individual may be able to identify bulk asbestos by its 
appearance and physical properties, the identification can be difficult 
when the asbestos is dispersed in a dust sample or is present in low 
concentration in a rock.
    Due to a lack of consensus in the regulatory and scientific 
communities, revisions to MSHA's use of PCM-based analytical methods 
were not included within the scope of this rulemaking. If PCM-based 
analysis reveals a potential overexposure, MSHA will perform a TEM-
based analysis to confirm asbestos exposure levels. Further, MSHA will 
consider the use of alternative analytical methods for the measurement 
of airborne asbestos that meet the analytical equivalency criteria for 
OSHA's Reference Method once they are recognized by a laboratory 
accreditation organization. For example, NIOSH is supporting an ASTM 
inter-laboratory study to validate whether ASTM D7200-06, ``Standard 
Practice for Sampling and Counting Airborne Fibers, Including Asbestos 
Fibers, in Mines and Quarries, by Phase Contrast Microscopy and 
Transmission Electron Microscopy'' can meet the OSHA equivalency 
criteria and be accredited.
    a. Discussion of Microscope Properties.
    One issue commenters mentioned concerning PCM-based analytical 
methods is the limited resolution and magnification of light 
microscopes compared to electron microscopes. The resolution of the 
microscope is the smallest separation between two objects that will 
allow them to be distinctly visible. The higher the resolving power of 
a microscope, the smaller the distance can be between two particles and 
have them still appear as two distinct particles. Resolution is about 
0.2 [mu]m using PCM compared with 0.0002 [mu]m using TEM. This means 
that an analyst who sees a single fiber using PCM may see a number of 
thinner fibers using TEM. Individual fibrils of chrysotile are about 
0.05 [mu]m in diameter while amphibole fibrils are about 0.1 [mu]m in 
diameter. Using TEM, the analyst is able to see thinner fibers and, 
therefore, should be able to see more fibers than when using PCM.
    Magnification is the ratio of the size that the object appears 
under the microscope to its actual size. A PCM-based analysis of air 
samples for asbestos typically uses a magnification of 400 to 450 times 
(x) the object's actual size. In contrast, a TEM-based analysis 
typically uses a magnification of 10,000x. As a result, an analyst 
using PCM sees a larger amount of the sample than one using TEM, 
although in less detail.
    b. Variability in Counting Asbestos Fibers Using PCM.
    Commenters generally supported MSHA's use of a PCM-based analytical 
method for the initial analysis of fiber samples for determining 
compliance. One of the commenters' major concerns focused on the 
variability of fiber counting procedures. MSHA understands that the 
PCM-based analytical methods yield considerable variability in counting 
fibers because it is dependent on a number of related variables, such 
as the optical performance of the microscope, the optical properties of 
the prepared sample, and the proportion of fine particles.\54\
---------------------------------------------------------------------------

    \54\ Rooker et al., 1982.
---------------------------------------------------------------------------

    OSHA recognized the variability of using a PCM-based analytical 
method in its rulemaking. The requirements listed at 29 CFR 1910.1001 
Appendix A minimize the effect of the known variability by describing 
the essential steps of a generic sampling and analytical procedure. 
OSHA also established criteria to limit variability. Subsequently, 
other papers have addressed variability issues related to PCM counting 
techniques.\55\
---------------------------------------------------------------------------

    \55\ Pang, 2000; Harper and Bartolucci, 2003.
---------------------------------------------------------------------------

    Commenters suggested a number of techniques to reduce the 
variability in counting fibers on mine air samples. Some asked that 
MSHA consider respirable or thoracic sampling to minimize interference 
from large particles that can obscure asbestos fibers on the filter. 
Some supported a counting technique based on the typical 
characteristics of asbestos in air. Others recommended using a higher 
aspect ratio to increase the probability that the structures counted 
are fibers. Another commenter stated that several approaches have been 
tried to remove non-asbestos minerals from samples, such as low 
temperature ashing or dissolution, but these approaches are not useful 
for mining samples. Many commenters suggested the development of 
differential counting techniques that consider the fiber morphology and 
the distributions or populations of distinct fiber groups with 
characteristic dimensions to analyze mine air samples for fibers. Other 
commenters stated that particle characteristics could not be used 
reliably to differentiate fibers from cleavage fragments when examining 
relatively small numbers of fibers. Several commenters suggested the 
development of a new analytical method for asbestos in mine air 
samples.
    Much of the variability in counting asbestos is attributed to the 
visual acuity of the analyst in observing and sizing fibers and in 
interpreting the counting rules.\56\ Overall, commenters recognized 
that it takes far less time to develop expertise in counting fibers 
using PCM than in developing expertise using TEM. NIOSH has developed a 
40-hour training course for analysts as an adequate prerequisite to 
conducting total fiber counts using PCM. To differentially count 
asbestos fibers, an analyst must have advanced knowledge of mineralogy 
and expertise in the microscopic techniques used. This knowledge and 
expertise can be gained only by years of experience counting fiber 
samples collected in a variety of environments.
---------------------------------------------------------------------------

    \56\ Rooker et al., 1982.
---------------------------------------------------------------------------

    The availability of analyst training courses, and the formation of 
accreditation bodies requiring laboratory quality assurance programs, 
helps minimize the variations in measurements between and within 
laboratories.\57\ Accreditation bodies require laboratories to use 
standardized analytical methods. AIHA has the Asbestos Analyst Registry 
that specifies criteria for competence, education, and performance for 
analysts. In addition to these programs, MSHA's incorporation of OSHA's 
Appendix A helps minimize the subjectivity and increase consistency of 
measuring airborne asbestos concentrations by specifying core elements 
of an acceptable PCM-based analytical method.
---------------------------------------------------------------------------

    \57\ Schlect and Shulman, 1995.
---------------------------------------------------------------------------

3. MSHA's Incorporation of Appendix A of OSHA's Asbestos Standard
    MSHA's existing standards include basic elements of PCM-based 
analytical methods. These same basic elements for asbestos exposure 
monitoring are included in the OSHA Reference Method in Appendix A of 
OSHA's asbestos standard. The evaluation or inclusion of methods that 
do not include these basic elements or that deviate from the criteria 
for counting fibers in MSHA's existing standards was not contemplated 
in the proposed rule and, therefore, is beyond the scope of this final 
rule.
    OSHA's Appendix A, the OSHA Reference Method (ORM), specifies the 
elements of an acceptable analytical method for asbestos and the 
quality

[[Page 11296]]

control procedures that laboratories performing the analysis must 
implement. To encourage innovation and technological advancement, the 
final rule allows for MSHA's acceptance of other analytical methods 
that are at least as effective in identifying potential asbestos 
overexposures as the OSHA Reference Method (29 CFR 1910.1001, Appendix 
A). MSHA considers the counting criteria for a fiber in the OSHA 
Reference Method to be statistically equivalent to that in MSHA's 
definition of a fiber.
    For the purpose of this final rule, MSHA considers a method to be 
statistically equivalent to the ORM and at least as effective as MSHA's 
existing method if it meets the following criteria from 29 CFR 
1910.1001(d)(6)(iii):

    (A) Replicate exposure data used to establish equivalency are 
collected in side-by-side field and laboratory comparisons; and
    (B) The comparison indicates that 90% of the samples collected 
in the range 0.5 to 2.0 times the permissible limit have an accuracy 
range of plus or minus 25 percent of the ORM results at a 95% 
confidence level as demonstrated by a statistically valid protocol; 
and
    (C) The equivalent method is documented and the results of the 
comparison testing are maintained.

Although MSHA can calculate concentrations below 0.1 f/cc, neither 
NIOSH 7400 nor OSHA ID 160 sampling and analytical methods obtain 
statistically reliable, repeatable measurements within  25 
percent of the mean with 95 percent confidence for concentrations lower 
than 0.1 f/cc. The preamble to OSHA's 1994 asbestos rule (59 FR 40967) 
states that 0.1 f/cc is ``the practical lower limit of feasibility for 
measuring asbestos levels reliably.''
    Appendix A lists NIOSH 7400 and OSHA ID-160 as analytical methods 
that meet these equivalency criteria. MSHA will consider other 
analytical methods that afford an equivalent measurement alternative as 
they become available.
4. Epidemiological Studies and Health Risk Data Based on PCM Analytical 
Methods
    A number of commenters pointed out that a PCM-based methodology 
counts more than asbestos. These commenters suggested that the lower 
risk seen in epidemiological studies relating PCM-based exposure 
estimates to adverse health outcomes in miners was due to the other 
material inherent in air samples taken in a mining environment. They 
speculated that non-asbestos dust particles had been counted and 
included in the estimated concentrations, which would have 
overestimated asbestos exposures. MSHA acknowledges the possible 
overestimation of asbestos-related disease in applying OSHA's risk 
assessment to mining exposures based solely on PCM analytical results. 
For this reason, by policy, MSHA uses a subsequent TEM analysis to 
identify asbestos minerals and minimize this overestimation when 
determining asbestos exposures. MSHA has not found sufficient 
information to make a ``differential risk'' determination for the 
mining industry within OSHA's quantitative risk assessment, which MSHA 
uses as the basis for this final rule.
5. Discussion of Cleavage Fragments and Non-Asbestos Minerals
    During this rulemaking, MSHA has received many comments regarding 
cleavage fragments. MSHA has not addressed cleavage fragments in this 
final rule. To do so would require a change in both the analytical 
method and the definition of asbestos, neither of which were 
contemplated in the proposed rule and are, therefore, beyond the scope 
of this final rule. The final rule retains MSHA's PCM-based analytical 
method. To minimize the impact of cleavage fragments on sampling 
results, however, MSHA will continue its policy of conducting a 
subsequent TEM-based analysis on samples with PCM results that exceed 
the PEL.
    Many commenters expressed concern that standard phase contrast 
counting techniques are not specific in determining exposure to only 
the six Federal asbestos minerals and may misidentify cleavage 
fragments as asbestos fibers. PCM-based analytical methods do not 
distinguish between asbestos and any other fiber meeting the size and 
aspect ratio criteria. A number of commenters highlighted the seeming 
contradiction between MSHA's stated intent to exclude cleavage 
fragments from the standard and the Agency's selection of a PCM-based 
analytical method that may identify elongated amphibole cleavage 
fragments as asbestos fibers.
    Commenters suggested several ways to eliminate cleavage fragments. 
For example, some suggested that MSHA use a revised PCM-based method 
with differential counting criteria that referenced OSHA's 29 CFR 
1910.1001 Appendices B and C.\58\ Others suggested a proposed ASTM 
method, which was adopted in June 2006 (ASTM D 7200-06). Several 
recommended a fiber population analysis that examined samples for the 
characteristics of commercial asbestos listed in Appendix A of EPA's 
Method for the Determination of Asbestos in Bulk Building Materials 
(EPA, 1993).
---------------------------------------------------------------------------

    \58\ Appendix B (non-mandatory) is a detailed procedure for 
asbestos sampling and analysis. OSHA removed Appendix C (mandatory), 
which specified qualitative and quantitative fit testing procedures, 
when they promulgated their respiratory protection standard (29 CFR 
1910.134). Given the context of the comment, MSHA thinks the 
commenter may have been referring to Appendix J, OSHA's PLM 
analytical method.
---------------------------------------------------------------------------

    MSHA acknowledges that PCM-based analytical methods for the 
quantitative analysis of asbestos samples have some limitations, 
especially if samples are collected in a mixed dust environment. PCM-
based analysis, however, addresses the key problem of needing to make a 
relatively fast, cost-effective evaluation of miners' work environments 
so as to improve their health protection. Using a PCM-based analytical 
method maintains the usefulness of the analytical results relative to 
the historic health data.\59\ When an exposure exceeds the full-shift 
or excursion PEL, MSHA uses a TEM-based method to confirm the presence 
of asbestos.
---------------------------------------------------------------------------

    \59\ Wylie et al., 1985.
---------------------------------------------------------------------------

D. Sec.  71.701(c) and (d): Sampling; General Requirements (Controlling 
Asbestos Exposures in Coal Mines)

    This final rule retains the proposed revision to add a reference to 
Sec.  71.702 in paragraphs (c) and (d) of Sec.  71.701 to clarify 
MSHA's intent that coal mine operators control miners' exposures to 
asbestos. MSHA received no substantive comments on this proposed 
change.

VI. Regulatory Analyses

A. Executive Order (E.O.) 12866

    Executive Order (E.O.) 12866 (58 FR 51735) as amended by E.O. 13258 
(Amending Executive Order 12866 on Regulatory Planning and Review (67 
FR 9385)) requires regulatory agencies to assess both the costs and 
benefits of regulations. To comply with Executive Order 12866, MSHA has 
prepared a Regulatory Economic Analysis (REA) for this final rule. The 
REA contains supporting data and explanation for the summary materials 
presented in section VI of this preamble, including the covered mining 
industry, costs and benefits, feasibility, and small business impact. 
The REA is located on MSHA's Web site at http://www.msha.gov/regsinfo.htm. A copy of the REA can be obtained from MSHA's Office of 
Standards, Regulations, and Variances.
    Executive Order 12866 classifies a rule as a significant regulatory 
action

[[Page 11297]]

requiring review by the Office of Management and Budget if it has an 
annual effect on the economy of $100 million or more; creates a serious 
inconsistency or interferes with an action of another agency; 
materially alters the budgetary impact of entitlements or the rights of 
entitlement recipients; or raises novel legal or policy issues. MSHA 
has determined that the final rule would not have an annual effect of 
$100 million or more on the economy and, therefore, it is not an 
economically ``significant regulatory action'' pursuant to section 3(f) 
of E.O. 12866. MSHA, however, has concluded that the proposed rule is 
otherwise significant under Executive Order 12866 because it raises 
novel legal or policy issues.
1. Discussion of Benefits
    This final rule will reduce diseases arising from exposure to 
asbestos, and the associated costs to employers, miners' families, and 
society at large. Exposure to asbestos can cause lung cancer; 
mesothelioma; gastrointestinal cancer; cancers of the larynx, pharynx, 
and kidneys; asbestosis; and other respiratory diseases. Reduced 
miners' exposures will reduce adverse health effects both in terms of 
the incidence of disease affecting quality of life, and deaths from 
both cancer and non-cancer disease. These asbestos-related diseases 
cause a material impairment of human health or functional capacity.
    This benefit analysis quantifies the reduction in expected deaths 
to miners resulting from reduced exposure to airborne asbestos. The 
benefit is a result of reducing the 8-hour time-weighted average (TWA) 
permissible exposure limit (PEL) from 2 fibers per cubic centimeter (f/
cc) to 0.1 f/cc. MSHA acknowledges that this change will not eliminate 
the risk of asbestos-related material impairment of health. (See Table 
IV-1.)
    a. Summary of Benefits.
    By lowering the PEL to 0.1 f/cc, MSHA estimates the prevention of 
one occupationally related cancer death caused by asbestos exposure 
over the 55-year period beginning 10 years after implementation of the 
final rule. MSHA estimates that there will be benefits resulting from 
lowering the excursion limit, but is unable to quantify these benefits. 
This analysis underestimates the total benefits of the rule by 
quantifying only the cancer deaths prevented. The benefits do not 
include the reduced incidence of asbestosis-related disabilities.
    b. Calculation of Premature Deaths Prevented.
    MSHA limits the quantified benefits to an estimation of the number 
of cancer cases prevented. MSHA expresses the results as ``deaths 
prevented'' because the cancers associated with asbestos exposure 
almost always result in premature death.
    The benefits resulting from a reduction in the PEL depend on 
several factors including--
     Existing and projected exposure levels,
     Risk associated with each exposure level,
     Number of workers exposed at each exposure level, and
     Age of the miner at first exposure.

MSHA estimated the number of miners currently exposed and their levels 
of exposure from data on personal exposure sampling during regular and 
special inspections between January 2000 and May 2007. These data are 
available on MSHA's Web site at http://www.msha.gov. Section III of 
this preamble contains the characterization and assessment of exposures 
in mining.
    Laboratory results indicate that exposure concentrations are 
unevenly distributed across mines and among miners within mines. MSHA 
uses four fiber concentration levels to estimate the risk to miners. 
The break points for these exposure levels are the existing and final 
exposure limits as follows: Less than 0.1 f/cc, 0.1 to less than 1 f/
cc, 1 f/cc to less than 2 f/cc, and 2 f/cc or greater. Approximately 86 
percent of MSHA's PCM-based fiber sampling results are below 0.1 f/cc. 
Approximately 97 percent of MSHA's TEM-based asbestos sampling results 
are below 0.1 f/cc. Based on MSHA's sampling data, concentrations 
ranged between 0.0 and 38.1 f/cc over these years. The highest 
concentration level in Table IV-1 is 10 f/cc. MSHA's calculations, 
therefore, use an upper exposure limit of 10 f/cc. Samples with 
exposure concentrations above 10 f/cc are included in this benefits 
analysis as 10 f/cc. MSHA's estimated benefits derive totally from the 
mines MSHA has sampled.
    MSHA applied OSHA's linear, no-threshold, dose-response risk 
assessment model to MSHA's existing PEL and final PEL to estimate the 
expected number of asbestos-related deaths. The expected reduction of 
deaths resulting from lowering the PEL will be the difference between 
the expected deaths at 2 f/cc and 0.1 f/cc.\60\ MSHA then applied these 
rates to the estimated number of miners exposed at the corresponding 
concentration based on MSHA sampling data. The result is an estimate of 
miners' deaths resulting from cancer due to occupational exposure to 
asbestos under existing exposure conditions.
---------------------------------------------------------------------------

    \60\ Nicholson, 1983; JRB Associates, 1983; OSHA (51 FR 22612), 
1986; OSHA (53 FR 35609), 1988; OSHA (59 FR 40964), 1994.
---------------------------------------------------------------------------

    c. Benefits of the 0.1 f/cc PEL.
    Deaths from lung cancer, mesotheliomas, gastrointestinal cancer, 
and asbestosis are the result of past exposures to much higher air 
concentrations of asbestos than those found in mines today. The risks 
of these diseases still exist, however, and these risks are significant 
for miners exposed to lower air concentrations of asbestos. Most 
diseases resulting from a more recent asbestos exposure may not become 
evident for another 20 to 30 years. When the results of TEM analysis 
are incorporated into the exposure data, MSHA estimated a reduction of 
one cancer death (per 314 miners exposed above 0.1 f/cc, or 5 per 1,000 
exposed) over a 55-year period starting 10 years after implementation 
of the lower 8-hour TWA PEL. This represents a 12 percent reduction in 
the miners' asbestos-related deaths that would be expected if existing 
exposures were to continue. The rate at which the incidence of the 
cancers decreases depends on several factors including--
     Latency of onset of cancer,
     Attrition of the mining workforce,
     Changing rates of competing causes of death,
     Dynamics of other risk factors,
     Changes in life expectancy, and
     Advances in cancer treatments.
    d. Benefits of the 1 f/cc Excursion Limit.
    The intended effect of the excursion limit is to protect miners 
from the adverse health risks associated with brief fiber releases. 
MSHA believes that miners will be exposed to brief fiber releases even 
when airborne concentrations of asbestos do not exceed the PEL. For 
example, mechanics may be inadvertently exposed to airborne asbestos 
while working on older equipment that may have asbestos-containing 
parts. Miners may encounter brief fiber releases while drilling, 
dozing, blasting, or roof bolting in areas of naturally occurring 
asbestos. These short-term exposures can easily be above 1 f/cc; 
however, when averaged over an 8-hour shift, they fall within the 0.1 
f/cc PEL. However, because MSHA does not have sufficient data regarding 
the relationship between the frequency of brief fiber releases and 
adverse health risks, this analysis demonstrates the theoretical 
benefits from limiting short-term exposures to the excursion limit.
    This section estimates the benefits of the excursion limit of 1 f/
cc for one 30-

[[Page 11298]]

minute period per day. Two 30-minute exposures per day at 1 f/cc will 
exceed the 8-hour TWA, full shift exposure limit (i.e., 1 f/cc for 48 
minutes = 0.1 f/cc for 480 minutes).
    MSHA estimates the benefit of an excursion limit from the 
difference in concentration between the PEL and the excursion limit 
averaged over the full shift [(1 f/cc)/(16 30-minute periods) = 0.063 
f/cc]. The lifetime risk associated with an exposure to 0.1 f/cc is 
0.00336, if first exposed at age 25 and exposure continues every work 
day at that level for 45 years. The risk associated with exposure to 
0.063 f/cc using the same age and duration of exposure is 0.00212. The 
difference in lifetime risk is 0.00124, which equates to one additional 
premature death prevented for every 1,000 miners exposed to asbestos 
above the 1 f/cc excursion limit.
2. Discussion of Costs
    The final rule will result in total costs of approximately $201,000 
per year for all mines. The cost will be approximately $156,000 for 
metal and nonmetal mines and approximately $45,000 for coal mines. 
These costs represent less than 0.001 percent of the yearly revenues of 
$64.4 billion for the metal and nonmetal mining industry and $27.0 
billion for the coal mining industry.
    Table VI-1 presents MSHA's estimate of the total yearly compliance 
costs by compliance strategy and mine size. The total costs reported 
are projected costs, in 2006 dollars, based on MSHA's knowledge, 
experience, and available information.

                                 Table VI-1.--Summary of Yearly Compliance Costs
----------------------------------------------------------------------------------------------------------------
                                                        Compliance strategy
                                 ----------------------------------------------------------------    Total for
  Metal and nonmetal mine size       Selective                                                       metal and
                                      mining        Wet methods     Ventilation   Removal of ACM  nonmetal mines
----------------------------------------------------------------------------------------------------------------
1-19............................          $2,417          $2,820          $1,619          $1,750          $8,606
20-500..........................          11,242          19,673          28,048          21,000          79,962
501+............................           3,747           6,558          41,278          15,750          67,333
    Total.......................          17,406          29,050          70,945          38,500         155,901
----------------------------------------------------------------------------------------------------------------


 
                                                        Compliance strategy
                                 ---------------------------------------------------------------- Total for coal
         Coal mine size              Selective                                                         mines
                                      mining        Wet methods     Ventilation   Removal of ACM
----------------------------------------------------------------------------------------------------------------
1-19............................  ..............  ..............  ..............            $875            $875
20-500..........................  ..............  ..............  ..............          12,250          12,250
501+............................  ..............  ..............  ..............          31,500          31,500
    Total.......................  ..............  ..............  ..............          44,625          44,625
----------------------------------------------------------------------------------------------------------------

B. Feasibility

    MSHA has determined that the requirements of this final rule are 
both technologically and economically feasible.
    In the discussion of PELs in section V.B of this preamble, MSHA 
stated that there is a residual risk of adverse health effects for 
miners exposed at the PEL. MSHA considered proposing a lower PEL as a 
regulatory alternative to further reduce the risk of adverse health 
effects from a working lifetime of exposure. When OSHA reduced the PEL 
from 0.2 to 0.1 f/cc in 1994, OSHA concluded that this concentration is 
``the practical lower limit of feasibility for measuring asbestos 
levels reliably.'' (59 FR 40967) About 85 percent of the sampled mines 
are already in compliance with the 0.1 f/cc PEL.
    This final rule is not a technology-forcing standard. All equipment 
required by the final rule and a variety of dust control strategies and 
control methods are already available in the marketplace and have been 
used successfully by the U.S. mining community to control asbestos 
exposures. MSHA has concluded that this final rule is technologically 
feasible.
    The mining industry would incur costs of about $201,000 yearly to 
comply with this final rule. These compliance costs represent less than 
0.001 percent of the yearly revenues of the mines covered by this rule 
(approximately $64.4 billion for metal and nonmetal and $27.0 billion 
for coal). MSHA has concluded that this final rule is economically 
feasible.

D. Regulatory Flexibility Analysis (RFA) and Small Business Regulatory 
Enforcement Fairness Act (SBREFA)

    Based on MSHA's data and experience, and information submitted to 
the record, the Agency has determined and here certifies that this 
final rule will not have a significant economic impact on a substantial 
number of small entities. The REA for this final rule (RIN: 1219-AB24), 
Asbestos Exposure Limit, contains the factual basis for this 
certification as well as complete details about data, equations, and 
methods used to calculate the costs and benefits. MSHA has placed the 
REA in the rulemaking docket and posted it on MSHA's Web site at http://www.msha.gov.

E. Other Regulatory Considerations

1. The National Environmental Policy Act of 1969 (NEPA)
    MSHA has reviewed the final rule in accordance with the 
requirements of NEPA of 1969 (42 U.S.C. 4321 et seq.), the regulations 
of the Council on Environmental Quality (40 CFR part 1500), and the 
Department of Labor's NEPA procedures (29 CFR part 11) and has assessed 
the environmental impacts. The Agency found that the final rule will 
have no significant impact on air, water, or soil quality; plant or 
animal life; the use of land; or other aspects of the human 
environment.
2. Paperwork Reduction Act of 1995
    The final rule contains no information collection or recordkeeping 
requirements. Thus, there are no additional paperwork burden hours and 
related costs associated with the final rule. Accordingly, the 
Paperwork Reduction Act requires no further agency action or analysis.
3. The Unfunded Mandates Reform Act of 1995
    MSHA has reviewed the final rule under the Unfunded Mandates Reform

[[Page 11299]]

Act of 1995 (2 U.S.C. 1501 et seq.). MSHA has determined that the final 
rule does not include any Federal mandate that may result in increased 
expenditures by State, local, or tribal governments; nor does it 
increase private sector expenditures by more than $100 million in any 
one year or significantly or uniquely affect small governments. 
Accordingly, the Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1501 et 
seq.) requires no further agency action or analysis.
    4. Treasury and General Government Appropriations Act of 1999 
(Section 654: Assessment of Impact of Federal Regulations and Policies 
on Families)
    Section 654 of the Treasury and General Government Appropriations 
Act of 1999 (5 U.S.C. 601 note) requires agencies to assess the impact 
of Agency action on family well-being. MSHA has determined that the 
final rule will have no affect on family stability or safety, marital 
commitment, parental rights and authority, or income or poverty of 
families and children. Accordingly, MSHA certifies that the final rule 
will not impact family well-being.
5. Executive Order 12630: Government Actions and Interference with 
Constitutionally Protected Property Rights
    The final rule does not implement a policy with takings 
implications. Accordingly, E.O. 12630 requires no further Agency action 
or analysis.
6. Executive Order 12988: Civil Justice Reform
    The final rule was written to provide a clear legal standard for 
affected conduct and was carefully reviewed to eliminate drafting 
errors and ambiguities, so as to minimize litigation and undue burden 
on the Federal court system. Accordingly, the final rule meets the 
applicable standards provided in section 3 of E.O. 12988, Civil Justice 
Reform.
7. Executive Order 13045: Protection of Children from Environmental 
Health Risks and Safety Risks
    The final rule has no adverse impact on children. Accordingly, 
under E.O. 13045, no further Agency action or analysis is required.
8. Executive Order 13132: Federalism
    The final rule does not have ``federalism implications,'' because 
it does not ``have substantial direct effects on the States, on the 
relationship between the national government and the States, or on the 
distribution of power and responsibilities among the various levels of 
government.'' Accordingly, Executive Order 13132, Federalism, requires 
no further agency action or analysis.
9. Executive Order 13175: Consultation and Coordination with Indian 
Tribal Governments
    The final rule does not have ``tribal implications,'' because it 
does not ``have substantial direct effects on one or more Indian 
tribes, on the relationship between the Federal government and Indian 
tribes, or on the distribution of power and responsibilities between 
the Federal government and Indian tribes.'' Accordingly, under E.O. 
13175, no further Agency action or analysis is required.
10. Executive Order 13211: Actions Concerning Regulations That 
Significantly Affect Energy Supply, Distribution, or Use
    Executive Order 13211 requires agencies to publish a statement of 
energy effects when a rule has a significant energy action that 
adversely affects energy supply, distribution or use. MSHA has reviewed 
the final rule for its energy effects because the final rule applies to 
the coal mining sector. MSHA has concluded that the final rule is not a 
significant energy action because it will not have significant adverse 
effect on the supply, distribution, or use of energy. Further, because 
the final rule will result in yearly costs of approximately $45,000 to 
the coal mining industry, relative to annual revenues of $27.0 billion 
in 2006, it is not a significant energy action because it is not likely 
to have a significant adverse effect on the supply, distribution, or 
use of energy. Accordingly, under this analysis, no further Agency 
action or analysis is required.
11. Executive Order 13272: Proper Consideration of Small Entities in 
Agency Rulemaking
    MSHA has thoroughly reviewed the final rule to assess and take 
appropriate account of its potential impact on small businesses, small 
governmental jurisdictions, and small organizations. As discussed in 
section VI.D of this preamble, MSHA has determined and certified that 
the final rule would not have a significant economic impact on a 
substantial number of small entities. Accordingly, Executive Order 
13272, Proper Consideration of Small Entities in Agency Rulemaking, 
requires no further agency action or analysis.

VII. Copy of the OSHA Reference Method (ORM)

    MSHA's existing asbestos standards require that the analyst 
determine fiber concentrations using a phase contrast microscopy 
analytical method with 400-450X magnification. The ORM contains these 
requirements. The definition of fiber in MSHA's final rule includes the 
same characteristics as in the existing standards, i.e., longer than 5 
[mu]m with a length to width ratio of at least 3:1. Although the ORM 
requires counting fibers 5 [mu]m or longer, there is no practical 
difference between these criteria considering the accuracy and 
precision of the analytical methods. NIOSH Method 7400 is equivalent to 
the ORM even though it requires counting fibers longer than 5 [mu]m. 
The ORM also requires that analysts ``* * * must have taken the NIOSH 
course for sampling and evaluating airborne asbestos dust or an 
equivalent course.''

29 CFR 1910.1001 Appendix A: OSHA Reference Method--Mandatory

    This mandatory appendix specifies the procedure for analyzing 
air samples for asbestos and specifies quality control procedures 
that must be implemented by laboratories performing the analysis. 
The sampling and analytical methods described below represent the 
elements of the available monitoring methods (such as Appendix B of 
their regulation, the most current version of the OSHA method ID-
160, or the most current version of the NIOSH Method 7400). All 
employers who are required to conduct air monitoring under paragraph 
(d) of the [OSHA] standard are required to utilize analytical 
laboratories that use this procedure, or an equivalent method, for 
collecting and analyzing samples.
    Sampling and Analytical Procedure.
    1. The sampling medium for air samples shall be mixed cellulose 
ester filter membranes. These shall be designated by the 
manufacturer as suitable for asbestos counting. See below for 
rejection of blanks.
    2. The preferred collection device shall be the 25-mm diameter 
cassette with an open-faced 50-mm electrically conductive extension 
cowl. The 37-mm cassette may be used if necessary but only if 
written justification for the need to use the 37-mm filter cassette 
accompanies the sample results in the employee's exposure monitoring 
record. Do not reuse or reload cassettes for asbestos sample 
collection.
    3. An air flow rate between 0.5 liter/min and 2.5 liters/min 
shall be selected for the 25-mm cassette. If the 37-mm cassette is 
used, an air flow rate between 1 liter/min and 2.5 liters/min shall 
be selected.
    4. Where possible, a sufficient air volume for each air sample 
shall be collected to yield between 100 and 1,300 fibers per square 
millimeter on the membrane filter. If a filter darkens in appearance 
or if loose dust is seen on the filter, a second sample shall be 
started.
    5. Ship the samples in a rigid container with sufficient packing 
material to prevent

[[Page 11300]]

dislodging the collected fibers. Packing material that has a high 
electrostatic charge on its surface (e.g., expanded polystyrene) 
cannot be used because such material can cause loss of fibers to the 
sides of the cassette.
    6. Calibrate each personal sampling pump before and after use 
with a representative filter cassette installed between the pump and 
the calibration devices.
    7. Personal samples shall be taken in the ``breathing zone'' of 
the employee (i.e., attached to or near the collar or lapel near the 
worker's face).
    8. Fiber counts shall be made by positive phase contrast using a 
microscope with an 8 to 10 x eyepiece and a 40 to 45 x objective for 
a total magnification of approximately 400 x and a numerical 
aperture of 0.65 to 0.75. The microscope shall also be fitted with a 
green or blue filter.
    9. The microscope shall be fitted with a Walton-Beckett eyepiece 
graticule calibrated for a field diameter of 100 micrometers (2 micrometers).
    10. The phase-shift detection limit of the microscope shall be 
about 3 degrees measured using the HSE phase shift test slide as 
outlined below.
    a. Place the test slide on the microscope stage and center it 
under the phase objective.
    b. Bring the blocks of grooved lines into focus.

    Note: The slide consists of seven sets of grooved lines (ca. 20 
grooves to each block) in descending order of visibility from sets 1 
to 7, 7 being the least visible. The requirements for asbestos 
counting are that the microscope optics must resolve the grooved 
lines in set 3 completely, although they may appear somewhat faint, 
and that the grooved lines in sets 6 and 7 must be invisible. Sets 4 
and 5 must be at least partially visible but may vary slightly in 
visibility between microscopes. A microscope that fails to meet 
these requirements has either too low or too high a resolution to be 
used for asbestos counting.

    c. If the image deteriorates, clean and adjust the microscope 
optics. If the problem persists, consult the microscope 
manufacturer.
    11. Each set of samples taken will include 10 percent blanks or 
a minimum of 2 field blanks. These blanks must come from the same 
lot as the filters used for sample collection. The field blank 
results shall be averaged and subtracted from the analytical results 
before reporting. A set consists of any sample or group of samples 
for which an evaluation for this standard must be made. Any samples 
represented by a field blank having a fiber count in excess of the 
detection limit of the method being used shall be rejected.
    12. The samples shall be mounted by the acetone/triacetin method 
or a method with an equivalent index of refraction and similar 
clarity.
    13. Observe the following counting rules.
    a. Count only fibers equal to or longer than 5 micrometers. 
Measure the length of curved fibers along the curve.
    b. In the absence of other information, count all particles as 
asbestos that have a length-to-width ratio (aspect ratio) of 3:1 or 
greater.
    c. Fibers lying entirely within the boundary of the Walton-
Beckett graticule field shall receive a count of 1. Fibers crossing 
the boundary once, having one end within the circle, shall receive 
the count of one half (\1/2\). Do not count any fiber that crosses 
the graticule boundary more than once. Reject and do not count any 
other fibers even though they may be visible outside the graticule 
area.
    d. Count bundles of fibers as one fiber unless individual fibers 
can be identified by observing both ends of an individual fiber.
    e. Count enough graticule fields to yield 100 fibers. Count a 
minimum of 20 fields; stop counting at 100 fields regardless of 
fiber count.
    14. Blind recounts shall be conducted at the rate of 10 percent.
    Quality Control Procedures.
    1. Intralaboratory program. Each laboratory and/or each company 
with more than one microscopist counting slides shall establish a 
statistically designed quality assurance program involving blind 
recounts and comparisons between microscopists to monitor the 
variability of counting by each microscopist and between 
microscopists. In a company with more than one laboratory, the 
program shall include all laboratories and shall also evaluate the 
laboratory-to-laboratory variability.
    2. Interlaboratory program.
    a. Each laboratory analyzing asbestos samples for compliance 
determination shall implement an interlaboratory quality assurance 
program that as a minimum includes participation of at least two 
other independent laboratories. Each laboratory shall participate in 
round robin testing at least once every 6 months with at least all 
the other laboratories in its interlaboratory quality assurance 
group. Each laboratory shall submit slides typical of its own work 
load for use in this program. The round robin shall be designed and 
results analyzed using appropriate statistical methodology.
    b. All laboratories should also participate in a national sample 
testing scheme such as the Proficiency Analytical Testing Program 
(PAT), or the Asbestos Registry sponsored by the American Industrial 
Hygiene Association (AIHA).
    3. All individuals performing asbestos analysis must have taken 
the NIOSH course for sampling and evaluating airborne asbestos dust 
or an equivalent course.
    4. When the use of different microscopes contributes to 
differences between counters and laboratories, the effect of the 
different microscope shall be evaluated and the microscope shall be 
replaced, as necessary.
    5. Current results of these quality assurance programs shall be 
posted in each laboratory to keep the microscopists informed.
    [57 FR 24330, June 8, 1992; 59 FR 40964, Aug. 10, 1994]

VIII. References Cited in the Preamble

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Armstrong, B.K., N.H. de Klerk, A.W. Musk, and M.S.T. Hobbs. 
``Mortality in Miners and Millers of Crocidolite in Western 
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Bagatin, E., J.A. Neder, L.E. Nery, M. Terra-Filho, J. Kavakama, A. 
Castelo, V. Capelozzi, A. Sette, S. Kitamura, M. Favero, D.C. 
Moreira-Filho, R. Tavares, C. Peres, and M.R. Becklake. ``Non-
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Baron, Paul A. ``Measurement of Airborne Fibers: A Review,'' 
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Workers,'' Annals New York Academy of Sciences, pp. 23-29, 1979.
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Eagen, Tomas M.L., Amund Gulsvik, Geir E. Eide, and Per S. Bakke. 
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Thomas, P.P.H. Hamel, I. Webster, and T. Hastie. ``Risk of 
Asbestosis in Crocidolite and Amosite Mines in South Africa,'' 
Annals New York Academy of Sciences, pp. 35-52, 1979.
JRB Associates. ``Benefits Assessment of Emergency Temporary and 
Proposed Asbestos Standards, Final Report,'' Prepared by Marthe B. 
Kent, William G. Perry, and Christine B. New for OSHA Office of 
Regulatory Analysis, November 3, 1983.
Kuempel, E.D., L.T. Stayner, J.D. Dement, S.J. Gilbert, and M.J. 
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List of Subjects

30 CFR Parts 56 and 57

    Air quality, Asbestos, Chemicals, Hazardous substances, Metals, 
Mine safety and health.

30 CFR Part 71

    Air quality, Asbestos, Chemicals, Coal mining, Hazardous 
substances, Mine safety and health.

    Dated: February 22, 2008.
Richard E. Stickler,
Acting Assistant Secretary for Mine Safety and Health.

0
For the reasons set out in the preamble, and under the authority of the 
Federal Mine Safety and Health Act of 1977, MSHA is amending chapter I 
of title 30 of the Code of Federal Regulations as follows.

PART 56--SAFETY AND HEALTH STANDARDS--SURFACE METAL AND NONMETAL 
MINES

0
1. The authority citation for part 56 continues to read as follows:

    Authority: 30 U.S.C. 811.

0
2. Section 56.5001 is amended by revising paragraph (b) to read as 
follows:


Sec.  56.5001  Exposure limits for airborne contaminants.

* * * * *
    (b) Asbestos standard--(1) Definitions. Asbestos is a generic term 
for a number of hydrated silicates that, when crushed or processed, 
separate into flexible fibers made up of fibrils. As used in this 
part--
    Asbestos means chrysotile, cummingtonite-grunerite asbestos 
(amosite), crocidolite, anthophylite asbestos, tremolite asbestos, and 
actinolite asbestos.
    Fiber means a particle longer than 5 micrometers ([mu]m) with a 
length-to-diameter ratio of at least 3-to-1.
    (2) Permissible Exposure Limits (PELs)--(i) Full-shift limit. A 
miner's personal exposure to asbestos shall not exceed an 8-hour time-
weighted average full-shift airborne concentration of 0.1 fiber per 
cubic centimeter of air (f/cc).
    (ii) Excursion limit. No miner shall be exposed at any time to 
airborne concentrations of asbestos in excess of 1 fiber per cubic 
centimeter of air (f/cc) as averaged over a sampling period of 30 
minutes.
    (3) Measurement of airborne fiber concentration. Fiber 
concentration shall be determined by phase contrast microscopy using a 
method statistically equivalent to the OSHA Reference Method in OSHA's 
asbestos standard found in 29 CFR 1910.1001, Appendix A.
* * * * *

PART 57--SAFETY AND HEALTH STANDARDS--UNDERGROUND METAL AND 
NONMETAL MINES

0
3. The authority citation for part 57 continues to read as follows:

    Authority: 30 U.S.C. 811.

0
4. Section 57.5001 is amended by revising paragraph (b) to read as 
follows:


Sec.  57.5001  Exposure limits for airborne contaminants.

* * * * *
    (b) Asbestos standard--(1) Definitions. Asbestos is a generic term

[[Page 11304]]

for a number of hydrated silicates that, when crushed or processed, 
separate into flexible fibers made up of fibrils. As used in this 
part--
    Asbestos means chrysotile, cummingtonite-grunerite asbestos 
(amosite), crocidolite, anthophylite asbestos, tremolite asbestos, and 
actinolite asbestos.
    Fiber means a particle longer than 5 micrometers ([mu]m) with a 
length-to-diameter ratio of at least 3-to-1.
    (2) Permissible Exposure Limits (PELs)--(i) Full-shift limit. A 
miner's personal exposure to asbestos shall not exceed an 8-hour time-
weighted average full-shift airborne concentration of 0.1 fiber per 
cubic centimeter of air (f/cc).
    (ii) Excursion limit. No miner shall be exposed at any time to 
airborne concentrations of asbestos in excess of 1 fiber per cubic 
centimeter of air (f/cc) as averaged over a sampling period of 30 
minutes.
    (3) Measurement of airborne fiber concentration. Fiber 
concentration shall be determined by phase contrast microscopy using a 
method statistically equivalent to the OSHA Reference Method in OSHA's 
asbestos standard found in 29 CFR 1910.1001, Appendix A.
* * * * *

PART 71--MANDATORY HEALTH STANDARDS--SURFACE COAL MINES AND SURFACE 
WORK AREAS OF UNDERGROUND COAL MINES

0
5. The authority citation for part 71 continues to read as follows:

    Authority: 30 U.S.C. 811, 951, 957.

0
6. Section 71.701 is amended by revising paragraphs (c) and (d) to read 
as follows:


Sec.  71.701  Sampling; general requirements.

* * * * *
    (c) Where concentrations of airborne contaminants in excess of the 
applicable threshold limit values, permissible exposure limits, or 
permissible excursions are known by the operator to exist in a surface 
installation or at a surface worksite, the operator shall immediately 
provide necessary control measures to assure compliance with Sec.  
71.700 or Sec.  71.702, as applicable.
    (d) Where the operator has reasonable grounds to believe that 
concentrations of airborne contaminants in excess of the applicable 
threshold limit values, permissible exposure limits, or permissible 
excursions exist, or are likely to exist, the operator shall promptly 
conduct appropriate air sampling tests to determine the concentration 
of any airborne contaminant which may be present and immediately 
provide the necessary control measures to assure compliance with Sec.  
71.700 or Sec.  71.702, as applicable.

0
7. Section 71.702 is revised to read as follows:


Sec.  71.702  Asbestos standard.

    (a) Definitions. Asbestos is a generic term for a number of 
hydrated silicates that, when crushed or processed, separate into 
flexible fibers made up of fibrils. As used in this part--
    Asbestos means chrysotile, cummingtonite-grunerite asbestos 
(amosite), crocidolite, anthophylite asbestos, tremolite asbestos, and 
actinolite asbestos.
    Fiber means a particle longer than 5 micrometers ([mu]m) with a 
length-to-diameter ratio of at least 3-to-1.
    (b) Permissible Exposure Limits (PELs)-- (1) Full-shift limit. A 
miner's personal exposure to asbestos shall not exceed an 8-hour time-
weighted average full-shift airborne concentration of 0.1 fiber per 
cubic centimeter of air (f/cc).
    (2) Excursion limit. No miner shall be exposed at any time to 
airborne concentrations of asbestos in excess of 1 fiber per cubic 
centimeter of air (f/cc) as averaged over a sampling period of 30 
minutes.
    (c) Measurement of airborne fiber concentration. Fiber 
concentration shall be determined by phase contrast microscopy using a 
method statistically equivalent to the OSHA Reference Method in OSHA's 
asbestos standard found in 29 CFR 1910.1001, Appendix A.

 [FR Doc. E8-3828 Filed 2-28-08; 8:45 am]
BILLING CODE 4510-43-P