[Federal Register Volume 62, Number 81 (Monday, April 28, 1997)]
[Proposed Rules]
[Pages 22998-23002]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-10722]



[[Page 22997]]

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Part II





Department of Labor





_______________________________________________________________________



Mine Safety and Health Administration



_______________________________________________________________________



30 CFR Parts 56, 57, and 75



Safety Standards for Roof Bolts in Metal and Nonmetal Mines and 
Underground Coal Mines; Proposed Rule

  Federal Register / Vol. 62, No. 81 / Monday, April 28, 1997 / 
Proposed Rules  

[[Page 22998]]


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DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 56, 57, and 75

RIN 1219-AB00


Safety Standards for Roof Bolts in Metal and Nonmetal Mines and 
Underground Coal Mines

AGENCY: Mine Safety and Health Administration, Labor.

ACTION: Proposed rule.

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SUMMARY: The Mine Safety and Health Administration (MSHA) is revising 
its safety standards for roof and rock bolts at metal and nonmetal 
mines and underground coal mines by updating the reference to the 
American Society for Testing and Materials (ASTM) standard for roof and 
rock bolts and accessories. The new reference reflects technological 
advances in the design of roof and rock bolts and support materials. It 
would improve the level of protection provided by the standards 
currently in use.

DATES: Submit written comments on or before June 27, 1997. Submit 
written comments on the information collection requirements by June 27, 
1997.

ADDRESSES: Send written comments on this proposed rule to the Mine 
Safety and Health Administration, Office of Standards, Regulations, and 
Variances, 4015 Wilson Boulevard, Room 631, Arlington, Virginia 22203. 
Commenters are encouraged to send comments on a computer disk or via e-
mail to [email protected], along with an original hard copy. Submit 
written comments on the information collection requirements to the 
Office of Information and Regulatory Affairs, OMB, New Executive Office 
Bldg., 725 17th St. NW., Room 10235, Washington, DC 20503, Attn: Desk 
Officer for MSHA.

FOR FURTHER INFORMATION CONTACT: Patricia W. Silvey, Director; Office 
of Standards, Regulations, and Variances, MSHA; phone: 703-235-1910, 
fax: 703-235-5551.

SUPPLEMENTARY INFORMATION:

I. Paperwork Reduction Act

    On August 29, 1995, the Office of Management and Budget (OMB) 
published a final rule in the Federal Register (60 FR 44978) 
implementing the new Paperwork Reduction Act of 1995 (PRA 95). 
Consistent with PRA 95, these OMB rules expanded the definition of 
``information'' to clarify that a ``certification'' would involve the 
collection of ``information'' if the Agency used it to monitor 
compliance. Mine operators currently are required to obtain a 
certification statement that the testing and manufacture of roof and 
rock bolts comply with the specified standard, and to keep a copy of 
this certification statement so that it can be made available to 
miners' representatives and representatives of the Secretary of Labor 
(the Secretary). Although the proposed rule would not change this 
requirement, it is now considered an information collection burden 
because of the expanded definition of ``information'' under PRA 95. The 
burden hours and costs associated with roof bolt certifications, 
therefore, do not reflect any increase for the mining industry.
    The collection of information contained in this proposal is subject 
to review by OMB under the PRA 95. The title, description, and 
respondent description of the information collection are discussed 
below with an estimate of the annual information collection burden. 
Included in the estimate is the time to obtain the manufacturer's 
signature and file the form.
    With respect to the following collection of information, MSHA 
invites comments on: (1) Whether the proposed collection of information 
is necessary for proper performance of MSHA's functions, including 
whether the information will have practical utility; (2) the accuracy 
of MSHA's estimate of the burden of the proposed collection of 
information, including the validity of the methodology and assumptions 
used; (3) ways to enhance the quality, utility, and clarity of the 
information to be collected; and (4) ways to minimize the burden of the 
collection of information on respondents, including through the use of 
automated collection techniques, when appropriate, and other forms of 
information technology.
    Description: Sections 56.3203(a)(1), 57.3203(a)(1), and 
75.204(a)(1) would require the mine operator to obtain a manufacturer's 
certification that the material was manufactured and tested in 
accordance with the specifications of ASTM F432-95. Sections 
56.3203(a)(2), 57.3203(a)(2), and 75.204(a)(2) require that the 
certification be made available to an authorized representative of the 
Secretary. MSHA estimates that it would take the mine operator about 3 
minutes to obtain a signature and file the form. Agency experience has 
shown that major roof and rock bolt manufacturers routinely provide a 
certification to mine operators at the time of the initial contract and 
update the certification annually. Smaller manufacturers provide a 
certification at the time of initial contract and upon request from the 
mine operator.
    Description of Respondents: The respondents are mine operators. 
MSHA estimates that this provision annually affects 653 surface metal 
and nonmetal mines; 185 underground metal and nonmetal mines; and 973 
underground coal mines.
    Information Collection Burden: The total estimated annual 
information collection burden for surface metal and nonmetal mines is 
about 33 hours at an estimated annual cost of about $1,180. The total 
estimated annual information collection burden for underground metal 
and nonmetal mines is about 9 hours at an estimated annual cost of 
about $330. The total estimated annual information collection burden 
for underground coal mines is about 49 hours at an estimated annual 
cost of about $2,040.
    The following chart summarizes MSHA's estimates by section.

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Number of                                  
                  Regulation in 30 CFR                       Number of       Hours per       Number of     responses per   Annual costs     Total hours 
                                                            respondents      response        responses      respondent                    per regulation
--------------------------------------------------------------------------------------------------------------------------------------------------------
56.3203(a)(1)...........................................             653            0.05             653               1          $1,175           32.65
57.3202(a)(1)...........................................             185            0.05             185               1             333            9.25
75.204(a)(1)............................................             973            0.05             973               1           2,043           48.65
      Total.............................................           1,811            0.05           1,811               1           3,551           90.55
--------------------------------------------------------------------------------------------------------------------------------------------------------

The burden hours and costs associated with roof bolt certifications do 
not reflect any increase for the mining industry because mine operators 
currently are required to perform these activities.
    Under section 3507(o) of PRA 95, the Agency has submitted a copy of 
this proposed rule to OMB for its review and approval of these 
information collections. Interested persons are requested to send 
comments regarding

[[Page 22999]]

these burden estimates or any other aspect of these collections of 
information, including suggestions for reducing these burdens, (1) 
directly to the Office of Information and Regulatory Affairs, OMB; 
Attention: Desk Officer for MSHA; 725 17th Street NW., Room 10235; 
Washington, DC 20503, and (2) to Patricia W. Silvey, Director; Office 
of Standards, Regulations, and Variances, MSHA; 4015 Wilson Boulevard, 
Room 631; Arlington, VA 22203.

II. Background

A. Metal and Nonmetal Mines

    On October 8, 1986, MSHA published a final rule (51 FR 36194) 
revising its safety standards for ground control at metal and nonmetal 
mines. This rulemaking included comprehensive rock bolt standards in 
Title 30 Code of Federal Regulations (CFR) Secs. 56/57.3203 which 
addressed the quality of rock fixtures and their installation. Roof and 
rock bolts and accessories are an integral part of ground control 
systems and are used to prevent the fall of roof, face, and ribs. 
Accidents involving falls of roof in underground mines or falls of 
highwall in surface mines have resulted in injuries and fatalities.
    These standards currently require that metal and nonmetal mine 
operators obtain a certification from the manufacturer that rock bolts 
and accessories are manufactured and tested in accordance with the 1983 
American Society for Testing and Materials (ASTM) publication 
``Standard Specification for Roof and Rock Bolts and Accessories'' 
(ASTM F432-83). The ASTM standard for roof and rock bolts and 
accessories is a consensus standard used throughout the United States. 
It contains specifications for the chemical, mechanical, and 
dimensional requirements for roof and rock bolts and accessories used 
for ground support systems.
    The manufacturer's certification is made available to an authorized 
representative of the Secretary to attest to the appropriate testing 
and manufacture of the rock bolts and accessories. Requiring that the 
mine operator obtain a certification from the manufacturer assures mine 
operators that the material they use meets technical requirements 
established to promote safety.

B. Underground Coal Mines

    MSHA published a final rule on February 8, 1990, (55 FR 4592) 
revising paragraphs (a) and (b) of Sec. 75.204. This standard 
references ASTM publication ``Standard Specification for Roof and Rock 
Bolts and Accessories'' (ASTM F432-88), which was the most recent 
revision available at that time. The final rule also requires mine 
operators to obtain a certification from the manufacturer that roof 
bolts and accessories are manufactured and tested in accordance with 
ASTM F432-88. To comply with this rule, mine operators are required to 
provide the certification document, upon request, to an authorized 
representative of the Secretary to establish that their roof bolts are 
designed and tested in accordance with the ASTM standard.
    This reference to the ASTM standard performs the same function as 
the reference to the 1983 ASTM standard for metal and nonmetal mining 
application. That is, the certificate assures mine operators that the 
material they use meets technical requirements established to promote 
safety.

III. Discussion

    MSHA has found that the existing certification requirement has been 
successful in maintaining compliance with requirements for roof and 
rock bolts and accessories. MSHA is proposing to retain the 
certification requirement and to update existing Secs. 56.3203, 
57.3203, and 75.204 by replacing the references to outdated ASTM F432-
83 and ASTM F432-88 with a new reference to ASTM F432-95.
    MSHA participated in the development of ASTM F432-95 through active 
representation at meetings of the American Mining Congress (predecessor 
organization to the National Mining Association) Roof Support Group. It 
was that committee that prepared the revised document for consideration 
by ASTM. The committee was open to all manufacturers of roof and rock 
bolts and accessories, and considered comments from all participants in 
developing the new specifications. MSHA Technical Support personnel 
conducted both laboratory and field studies which provide supporting 
data for the various changes. This proposed rulemaking has been 
followed closely by the National Mining Association, the United Mine 
Workers of America, and the United Steelworkers, and the Agency does 
not anticipate any opposition.
    MSHA is updating the standards because the Agency believes that 
ASTM F432-95 is more comprehensive than those referenced in existing 
standards, that it reflects advances in rock and roof bolt technology, 
and that it would provide better protection for miners than the 
standards currently in place. As discussed below, these revisions will 
not reduce the protection afforded miners by the MSHA standards 
currently in place.

A. New Products Addressed

    ASTM F432-95 covers products not addressed by the current standards 
including grouting materials, large diameter bolts, thread deformed 
bars, and formable anchorage devices.
1. Grouting Materials
    Grouting materials, which were not addressed by either ASTM F432-88 
or ASTM F432-83, are extensively covered by ASTM F432-95. The term 
``grouting materials'' is used in ASTM F432-95 to include any chemical 
materials (such as polyester, polyurethane, or epoxy resins) that are 
used to anchor mine roof bolts. While grouted bolts have been used 
successfully to support mine roofs since the 1970's, each manufacturer 
has a different method to describe proper application of grouting 
materials and their performance characteristics. This lack of 
standardization has caused confusion and occasional misapplication of a 
particular grout formulation and, therefore, has resulted in improperly 
grouted boreholes. Improperly grouted boreholes can result in poor bolt 
performance and, potentially, an inadequately supported roof. A survey 
of MSHA field personnel revealed that improper borehole grouting has 
been a contributing factor in roof fall accidents. Under ASTM F432-95, 
there are specific requirements regarding strength, cure rate, 
cartridge volume, and labeling that will standardize the production and 
application of grouting materials and reduce the likelihood that 
grouted bolts will be improperly installed.
2. Large Diameter Bolts
    Similarly, large diameter bolts, ranging in size from 1\1/8\ inch 
to 1\1/2\ inch, are now addressed by ASTM F432-95. MSHA field personnel 
report that these large diameter bolts are growing in popularity and 
are being used in areas of adverse roof conditions where smaller 
diameter bolts would fail. ASTM F432-95 provides standard strength and 
thread tolerance limits that ensure minimum performance levels and the 
interchangeability of components produced by different manufacturers. 
Compatibility is essential in ensuring that components acquired from 
different sources function properly when used together, such as 
mechanical anchors from one manufacturer and bolts from another, and 
provide an adequate margin of safety.
3. Thread Deformed Bars and Formable Anchorage Devices
    Two new technologies, thread deformed bars and formable anchorage

[[Page 23000]]

devices, also are addressed by ASTM F432-95. These bolting systems were 
not in use at the time ASTM F432-83 and ASTM F432-88 were adopted; but, 
their effectiveness has been demonstrated at a number of mines, which 
has led MSHA to approve their use in roof control plans. ASTM F432-95 
provides specific manufacturing, strength, and identification 
requirements for these products to ensure that minimum performance 
levels are met and that reliable products are available to the mine 
operator. Updating the roof control standards which reference the ASTM 
specifications covering these systems would reduce the time required by 
mine operators to receive approval to use these devices in the roof 
control plan, and eliminate the need for repetitive and time consuming 
underground tests.

B. Additional Safety Benefits

    ASTM F432-95 provides a number of additional safety benefits, 
including strength standards for couplers, tolerances for external and 
internal threads, dimensions for hardened washers, and bolt grading and 
identification systems.
1. Couplers
    Couplers are devices which connect two bolt sections. ASTM F432-95 
increases the strength standard for couplers and requires couplers to 
withstand the full breaking loads of the bolts with which they are 
used. In comparison, ASTM F432-88 requires only that couplers support 
the minimum yield and tensile loads of the connected bolts. In 
practice, roof bolt strengths often exceed the minimum strength 
requirements of ASTM F432-88 by a substantial margin, often in excess 
of 8,000 pounds. The new coupler requirements will ensure that the full 
strength of the bolting system is achieved and that catastrophic bolt 
failure, through premature coupler breakage, is prevented.
2. Internal and External Threads
    New tolerances have been established under ASTM F432-95 for both 
external threads primarily used for bolts, as well as internal threads 
used in couplers, anchor plugs, and nuts. MSHA experience indicates 
that the current thread tolerances of ASTM F432-88 and ASTM F432-83 are 
relatively tight and have been linked to thread seizure problems 
occasionally experienced during the installation of tensioned roof 
bolts. Thread seizure or binding can be caused by expansion anchor 
compression on bolt threads or the jamming of threads by small metal 
shards produced during the planned shearing of torque inhibiting pins 
or plugs. Thread seizure during roof bolt installation can 
significantly influence the torque-tension relationship. In turn, the 
torque check required by Secs. 56.3203(f)(2), 57.3203(f)(2), and 
75.204(f) (3), (4), and (5) may not indicate bolt tension accurately 
and, thus, fail to detect bolt installations that are not in compliance 
with those standards. The revised requirements of ASTM F432-95 would 
allow a slightly looser fit between mating threads (0.003 inch), which 
would reduce the possibility of thread seizure without affecting the 
strength of the component parts. The net result would be the improved 
reliability of roof bolt installations through more consistent bolt 
tensioning.
3. Hardened Washers
    ASTM F432-95 provides revised dimensions and tolerances for 
hardened washers that are used to enhance the uniformity of installed 
roof bolt tension. Current dimensions listed in ASTM F432-83 and ASTM 
F432-88 are such that it is impossible to use hardened washers with 
many deformed bars because the center hole dimensions are too small. In 
addition, the restricted outside diameter (2 inches nominal) prevents 
the effective use of hardened washers with large diameter bolts (i.e., 
1\1/2\ inch diameter) because of the grossly reduced bearing surface. 
The revised hardened washer dimensions of ASTM F432-95 are compatible 
with the bolts currently in use and ensure that the benefits of uniform 
bolt tension can be achieved with those systems.
4. Uniform Grading Systems
    ASTM F432-95 also contains a revised bolt grading system that would 
cover existing products and establish grade intervals for high strength 
bolts that may be developed in the future. The current reference 
standards of ASTM F432-83 and ASTM F432-88 are limited to grades 
currently in use. This essentially precludes the immediate use of 
higher strength bolts. The use of higher strength bolts now requires 
often unnecessary and time consuming tests to allow for MSHA approval 
of these bolts for use in an individual mine.
    In addition, the current system uses a single symbol for bolt head 
identification to designate both grade and diameter. Given the variety 
of bolting systems in use (\5/8\, \3/4\, \7/8\, 1, and 1\1/8\ inch 
diameters; grades 40, 55, 60, 75; plain and rebar bolts), a large 
number of symbols are used. Consequently, under the current system, 
identifying the grade and diameter of a bolt used underground, from the 
bolt head, has become difficult and extremely confusing. This increases 
the potential for the inadvertent use of bolt types either not 
prescribed by the roof control plan or not suitable for the roof 
conditions encountered. The revised grading and identification system 
of ASTM F432-95 would allow for the introduction of new high strength 
bolting systems and make it easier for miners to verify the grade and 
diameter of the bolts in use by looking at the bolt head.
    A grading system also has been established in ASTM F432-95 for 
threaded tapered plugs used in expansion anchors that specify minimum 
non-seizure and non-stripping loads for the bolt and plug threads. This 
system would enable mine operators to select expansion anchors with 
strength characteristics that are compatible with the bolting system in 
use, and ensure that thread seizure will not occur during bolt 
installation.
5. Low Strength Bolts
    Finally, ASTM F432-95 would eliminate the use of low strength grade 
30 bolts permitted by both ASTM F432-83 and 88, and delete certain 
chemical and grade requirements contained in those versions that 
unnecessarily restrict new technology. As a result, ASTM F432-95, 
through its improved specifications, would provide additional safety to 
miners as compared to the current specifications.
    MSHA expects that the elimination of the use of grade 30 bolts 
would not adversely impact the mining industry. MSHA allows a year for 
mine operators to use existing inventory. Further, MSHA experience 
indicates that the majority of mine operators are no longer using the 
30 grade bolts and that they are no longer being manufactured.

C. Existing Inventory

    This proposal would allow mine operators to use inventories of roof 
support components meeting the design criteria of ASTM F432-83 and ASTM 
F432-88 for up to one year from the effective date of the final rule. 
After that year, only roof support components meeting ASTM F432-95 
would be permitted to be installed. This one-year period will not 
result in a diminution of safety to miners and will allow mine 
operators, including small mines and seasonal operations, to exhaust 
existing supplies of roof support materials on site. It also would 
allow miners who use roof support materials to become sufficiently 
trained in the use of roof bolts and accessories that meet the 
requirements of ASTM F432-95. MSHA

[[Page 23001]]

specifically solicits comments from the mining community as to the 
suitability of this time period. MSHA is proposing that mine operators, 
however, could start using components meeting the ASTM F432-95 standard 
upon the effective date of the final rule.
    MSHA also believes that the one-year time period gives sufficient 
time for roof bolt manufacturers to consume present tooling, exhaust 
inventories of products meeting current specifications, and produce and 
make available to mine operators quantities of roof bolts meeting the 
design criteria of ASTM F432-95. MSHA specifically solicits comments 
from the mining community on whether this time period is adequate to 
supply mine operators with the kind and quantity of roof bolts needed.

IV. Executive Order 12866 and Regulatory Flexibility Act

    Executive Order 12866 requires that regulatory agencies assess both 
the costs and benefits of proposed regulations. MSHA estimates that the 
cost impact of the proposed rule is the same as under the existing 
rule. The primary benefit of the proposed rule is that it provides for 
advancements in roof bolt technology and, therefore, would increase 
protection for miners. MSHA has determined that this proposed rule does 
not meet the criteria of a significant regulatory action and, 
therefore, has not prepared a separate analysis of costs and benefits. 
The analysis contained in this preamble meets MSHA's responsibilities 
under Executive Order 12866 and the Regulatory Flexibility Act.
    The Regulatory Flexibility Act (RFA) requires regulatory agencies 
to consider a rule's impact on small entities. Under the RFA, MSHA must 
use the Small Business Administration (SBA) definition for a small mine 
of 500 or fewer employees or, after consultation with the SBA Office of 
Advocacy, establish an alternative definition for the mining industry 
by publishing that definition in the Federal Register for notice and 
comment. MSHA traditionally has considered small mines to be those with 
fewer than 20 employees. For the purposes of the RFA and this 
certification, MSHA has analyzed the impact of the proposed rule on all 
mines, on those with fewer than 20 employees, and on those with fewer 
than 500 employees, and has concluded that there is no cost impact on 
the mining industry.
    The Agency has provided a copy of this proposed rule and regulatory 
flexibility certification statement to the SBA Office of Advocacy. In 
addition, MSHA will mail a copy of the proposed rule, including the 
preamble and regulatory flexibility certification statement, to all 
affected mine operators.

Regulatory Flexibility Certification

    In accordance with section 605 of the RFA, MSHA certifies that this 
proposed rule would not have a significant economic impact on a 
substantial number of small entities. No small governmental 
jurisdictions or nonprofit organizations are affected.
    Under the Small Business Regulatory Enforcement Fairness Act 
(SBREFA) amendments to the RFA, MSHA must include in the proposed rule 
a factual basis for this certification. The Agency also must publish 
the regulatory flexibility certification in the Federal Register, along 
with its factual basis.

Factual Basis for Certification

    MSHA has used a qualitative approach in concluding that the 
proposed rule would not have a significant economic impact on a 
substantial number of small entities. MSHA anticipates that the cost of 
purchasing roof and rock bolts and accessories would not increase as a 
result of the proposed requirement that they meet the new ASTM 
specification (ASTM F432-95). This ASTM standard incorporates 
technological advances that are currently available and being used by 
the mining industry. Although MSHA does not expect any cost increases 
as a result of this proposed rule, there may be minimal costs which the 
Agency is not able to predict at this time. For this reason, MSHA 
solicits comments from the mining industry, especially small mines and 
roof bolt manufacturers, as to the impact of the proposed rule, both 
costs and benefits. With respect to costs, the Agency requests that 
commenters provide supporting information.

V. Unfunded Mandates Act

    For purposes of the Unfunded Mandates Reform Act of 1995, as well 
as E.O. 12875, this proposed rule does not include any Federal mandate 
that may result in increased expenditures by State, local, and tribal 
governments, or increased expenditures by the private sector of more 
than $100 million.

List of Subjects

30 CFR Parts 56 and 57

    Mine safety and health, Surface mining, Underground mining.

30 CFR Part 75

    Coal, Mine safety and health, Underground mining.

    Dated: April 17, 1997.
J. Davitt McAteer,
Assistant Secretary for Mine Safety and Health.

    For the reasons set out in the preamble, MSHA proposes to amend 
chapter I of title 30 of the Code of Federal Regulations as follows:

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

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

    Authority: 30 U.S.C. 811.

    2. Section 56.3203 is amended by revising the introductory text of 
paragraph (a), paragraph (a)(1), and the introductory text of paragraph 
(b) to read as follows:


Sec. 56.3203  Rock fixtures.

    (a) On and after April 28, 1998, for rock bolts and accessories 
addressed in ASTM F432-95, ``Standard Specification for Roof and Rock 
Bolts and Accessories,'' the mine operator shall--
    (1) Obtain a manufacturer's certification that the material was 
manufactured and tested in accordance with the specifications of ASTM 
F432-95; and
    (2) * * *
    (b) Fixtures and accessories not addressed in ASTM F432-95 may be 
used for ground support provided they--
* * * * *

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

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

    Authority: 30 U.S.C. 811.

    4. Section 57.3203 is amended by revising the introductory text of 
paragraph (a), paragraph (a)(1), and the introductory text of paragraph 
(b) to read as follows:


Sec. 57.3203  Rock fixtures.

    (a) On and after April 28, 1998, for rock bolts and accessories 
addressed in ASTM F432-95, ``Standard Specification for Roof and Rock 
Bolts and Accessories,'' the mine operator shall--
    (1) Obtain a manufacturer's certification that the material was 
manufactured and tested in accordance with the specifications of ASTM 
F432-95; and
    (2) * * *
    (b) Fixtures and accessories not addressed in ASTM F432-95 may be

[[Page 23002]]

used for ground support provided they--
* * * * *

PART 75--MANDATORY SAFETY STANDARDS--UNDERGROUND COAL MINES

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

    Authority: 30 U.S.C. 811.

    6. Section 75.204 is amended by revising the introductory text of 
paragraph (a), paragraph (a)(1), and the introductory text of paragraph 
(b) to read as follows:


Sec. 75.204  Roof bolting.

    (a) On and after April 28, 1998, for roof bolts and accessories 
addressed in ASTM F432-95, ``Standard Specification for Roof and Rock 
Bolts and Accessories,'' the mine operator shall--
    (1) Obtain a manufacturer's certification that the material was 
manufactured and tested in accordance with the specifications of ASTM 
F432-95; and
    (2) * *  *
    (b) Roof bolts and accessories not addressed in ASTM F432-95 may be 
used, provided that the use of such materials is approved by the 
District Manager based on--
* * * * *
[FR Doc. 97-10722 Filed 4-25-97; 8:45 am]
BILLING CODE 4510-43-P