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Seixas, N.S., T.G. Robins, M.D. Attfield,

and L.H. Moulton. Exposure-response

relationships for coal mine dust and

obstructive lung disease following enactment

of the Federal Coal Mine Health and Safety

Act of 1969. Am. J. Ind. Med. 21: 715–734,

1992.

Senate Report Number 95–181, at 21–22,

reprinted in 1977 United States Code

Congressional and Administrative News.

3421–22, 1977.

Silverman, L., C.E. Billings, and M.W.

First. Particle Size Analysis in Industrial

Hygiene. Academic Press, NY., 1971.

Snipes, M.B. Current information on lung

overload in nonrodent mammals: contrast

with rats. Inhal. Toxicol. 8 (suppl.): 91–109,

1996.

Soutar, C.A., and J.F. Hurley. Relationship

between dust exposure and lung function in

miners and ex-miners. Brit. J. Ind. Med. 43:

307–320, 1986.

Soutar, C.A., B.G. Miller, N. Gregg, A.D.

Jones, R.T. Cullen, and R.E. Bolton.

Assessment of human risks from exposure to

low toxicity occupational dusts. Ann. Occup.

Hyg. 41 (2): 123–133, 1997.

Starzynski, Z., K. Marek, A. Kujawska and

W. Szymczak. Mortality among different

occupational groups of workers with

pneumoconiosis: results from a registerbased cohort study. Amer. J. Ind. Med. 30:

718–725, 1996.

Tomb, T.F. Memorandum of August 31,

1981, from Thomas F. Tomb, Chief, Dust

Division, Pittsburgh Health Technology

Center, MSHA, to William Sutherland, Chief,

Division of Health, Coal Mine Safety and

Health, MSHA, Subject: Evaluation of

Criterion Used to Select Respirable Coal Mine

Dust Samples for Examination for Oversize

Particles.

Tomb, T.F. Memorandum of February 16,

1996, from Thomas F. Tomb, Chief, Dust

Division, Pittsburgh Safety and Health

Technology Center, MSHA, to Ronald J.

Schell, Chief, Division of Health, Coal Mine

Safety and Health, MSHA, Subject:

Investigation to Determine the Precision of

MSHA’s Automatic Weighing System for

Weighing Respirable Coal Mine Dust

Samples.

Tomb, T.F., H.N. Treaftis, R.L. Mundell,

and P.S. Parobeck. Comparison of Respirable

Dust Concentrations Measured With MRE

and Modified Personal Gravimetric Sampling

Equipment. BuMines RI 7772, 1973.

Tomb, T.F. Memorandum of September 1,

1994, from Thomas F. Tomb, Chief, Dust

Division, Pittsburgh Safety and Health

Technology Center, MSHA, to Ronald J.

Schell, Chief, Division of Health, Coal Mine

Safety and Health, MSHA, Subject:

Determination of the Precision of Setting the

Rotameter Ball to a Calibration Mark on

Personal Respirable Dust Sampling Pumps.

Treaftis, H.N. and T.F. Tomb. Effect of

Orientation on Cyclone Penetration

Characteristics. Am. Ind. Hyg. Assoc. J.,

35(10): 598–602, 1974.

Treaftis, H.N., T.F. Tomb, and H.F. Carden.

Effect of altitude on personal respirable dust

sampler calibration. Am. Ind. Hyg. Assoc. J.,

37(3): 133–138, 1976.

United Steelworkers of America v.

Marshall, 647 F.22d 1189, 1265 (D.C. Cir.

1981).

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Population Reports, Table 18. Resident

Population, by Race, 1980 to 1996, and

Projections, 1997 to 2050, P25–1095 and

P25–1130; and Population Paper Listing

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Population Reports, Table 119. Expectation

of Life and Expected Deaths, by Race, and

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U.S. EPA, Guidelines and methodology

used in the preparation of health effects

assessment chapters of the consent decree

water criteria documents. Federal Register

45(231): 79347–79357, 1980.

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Gregory R. Wagner, M.D., Acting Associate

Director for Mining, National Institute for

Occupational Safety and Health, to Ronald J.

Schell, Chief, Division of Health, Coal Mine

Safety and Health, MSHA.

Wagner, G.R. Letter of October 13, 1995,

from Gregory R. Wagner, M.D., National

Institute for Occupational Safety and Health,

to Ronald J. Schell, Chief, Division of Health,

Coal Mine Safety and Health, Mine Safety

and Health Administration.

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and Z. Wang. Respiratory impairments due to

dust exposure: a comparative study among

workers exposed to silica, asbestos, and

coalmine dust. Amer. J. Ind. Med. 31: 495–

502, 1997.

Webster, J.B., C.W. Chiaretta, and J.

Behling. Dust Control in High Productivity

Mines. SME Annual Meeting, Preprint,

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1990.

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Wager. Relation of FEV1 and peripheral blood

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1990.

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Occup. Environ. Med. 53: 129–135, 1996.

XVI. Regulatory Text

List of Subjects in 30 CFR Part 72

Coal, Health standards, Mine safety

and health, Underground mines,

Miscellaneous.

Dated: May 31, 2000.

Alexis M. Herman,

Secretary, Department of Labor.

Dated: May 31, 2000.

Donna E. Shalala,

Secretary, Department of Health and Human

Services.

Accordingly, it is proposed by the

Department of Labor, Mine Safety and

Health Administration, to amend

chapter I of title 30 of the Code of

Federal Regulations as follows:

PART 72—[AMENDED]

1. The authority citation for part 72

continues to read as follows:

Authority: 30 U.S.C. 811, 813(h), 957, 961.

2. Section 72. 500 is added to subpart

E of part 72 to read as follows:

§ 72.500 Single, full-shift

measurement of respirable coal mine

dust.

The Secretary may use a single, fullshift measurement of respirable coal

mine dust to determine average

concentration on a shift if that

measurement accurately represents

atmospheric conditions to which a

miner is exposed during such shift.

[FR Doc. 00–14075 Filed 7–6–00; 8:45 am]

BILLING CODE 4510–43–P

DEPARTMENT OF LABOR

Mine Safety and Health Administration

30 CFR Parts 70, 75 and 90

RIN 1219–AB14

Verification of Underground Coal Mine

Operators’ Dust Control Plans and

Compliance Sampling for Respirable

Dust

AGENCY: Mine Safety and Health

Administration (MSHA), Labor.

ACTION: Proposed rule; notice of

hearings.

SUMMARY: MSHA is proposing to revoke

existing operator respirable dust

sampling procedures under parts 70 and

90, and to implement new regulations

that would require each underground

coal mine operator to have a verified

mine ventilation plan. Under this

proposal, MSHA would verify the

effectiveness of the mine ventilation

plan for each mechanized mining unit

(MMU) in controlling respirable dust

under typical mining conditions. MSHA

would collect full-shift respirable dust

samples, called ‘‘verification samples,’’

to demonstrate the adequacy of the dust

control parameters specified in the mine

ventilation plan in maintaining the

concentration of respirable coal mine

and quartz dust at or below 2.0 mg/m3

and 100 μg/m3, respectively. The

adequacy of these parameters would be

demonstrated on shifts during which

the amount of the material produced is

at or above the ‘‘verification production

level’’ (VPL) or the tenth highest

production level recorded in the most

recent 30 production shifts.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42123

The proposal would require mine

operators to: First, set and maintain the

dust control parameters during MSHA

verification sampling at levels specified

in the plan; second, maintain and make

available to MSHA records of the

amount of material produced by each

mechanized mining unit during each

production shift; and third, additional

information in mine ventilation plans.

For longwall mine operations, MSHA is

also proposing to permit the use of

either approved powered, air-purifying

respirators (PAPRs) or verifiable

administrative controls as a

supplemental means of compliance if

MSHA has determined that further

reduction in respirable dust levels

cannot be achieved using all feasible

engineering or environmental controls

appropriate for the operational

conditions involved. In addition,

through this rule, MSHA would conduct

all compliance and abatement sampling

under existing parts 70 and 90.

DATES: Comments on the proposed rule

should be submitted on or before

August 7, 2000.

We are also announcing that we will

hold public hearings on the proposed

rule within 30 to 45 days of the

publication of this rule. The hearing

dates, times and specific locations will

be announced by a separate document

in the Federal Register. The rulemaking

record will remain open 7 days after the

last public hearing.

ADDRESSES: You may use mail, facsimile

(fax), or electronic mail to send your

comments to MSHA. Clearly identify

comments as such and send them—(1)

By mail to: Carol J. Jones, Director,

Office of Standards, Regulations, and

Variances, MSHA, 4015 Wilson

Boulevard, Room 631, Arlington, VA

22203;

(2) By fax to: MSHA, Office of

Standards, Regulations, and Variances,

703–235–5551; or

(3) By electronic mail to:

comments@msha.gov. Written

comments on the information collection

requirements may be submitted directly

to the Office of Information and

Regulatory Affairs, OMB, New

Executive Office Building, 725 17th

Street, NW, Washington, DC 20503,

Attn: Desk Officer for MSHA; and to

Carol J. Jones, Director, Office of

Standards, Regulations, and Variances,

MSHA 4015 Wilson Boulevard, Room

631, Arlington, VA 22203; by facsimile

to MSHA, at 703–235–5551; or by

electronic mail to comments@msha.gov.

The hearings will be held in the

following locations: Prestonsburg,

Kentucky, (Jenny Wiley State Resort

Park); Morgantown, West Virginia; and

Salt Lake City, Utah. The hearing dates,

times and specific locations will be

announced by a separate document in

the Federal Register.

FOR FURTHER INFORMATION CONTACT:

Carol J. Jones, Director, Office of

Standards, Regulations, and Variances,

MSHA; 703–235–1910.

SUPPLEMENTARY INFORMATION:

I. Table of Contents

The preamble discusses: revocation of

existing operator respirable dust

sampling requirements, revised

procedures for adjusting the respirable

dust standard when quartz is present,

the proposed rule, engineering controls

for respirable coal mine dust, dust

control parameters, supplemental

controls, health effects of exposure to

respirable coal mine dust, degree and

significance of the reduction in the

number of shifts during which there are

overexposures, an analysis of the

technological and economical feasibility

of this proposed rule, and regulatory

impact and flexibility analyses.

The preamble discussion follows this

outline:

I. Table of Contents

II. Background

A. Coal Mine Respirable Dust Task Group

B. Advisory Committee on the Elimination

of Pneumoconiosis Among Coal Mine

Workers

III. General Discussion

A. Revocation of the Operator Dust

Sampling Program

1. Pre-1980 Sampling Program

2. Post-1980 Sampling Program

3. Issues Affecting the Credibility of

Operator Compliance Sampling

4. Proposed Reforms to the Respirable Dust

Monitoring Program

a. Bimonthly Sampling

b. Abatement Sampling

c. Advantages of MSHA Compliance

Sampling Over Existing Program

B. Revised Procedures for Setting the

Applicable Dust Standard When Quartz

is Present

1. Current Procedures

2. Proposed Revised Procedures

3. Validity of Averaging Percentages

C. Respirable Dust Control Program for

Underground Coal Mines

1. Evaluating and Approving Plan

Requirements for Respirable Dust

Control

2. Compliance with Plan Requirements for

Respirable Dust Control

3. Monitoring Effectiveness of Plan

Requirements for Respirable Dust

Control

(a) Monitoring by Mine Operators

(b) Monitoring by MSHA

4. Proposed Procedures for Evaluating,

Approving, and Monitoring Plan

Requirements

D. Hierarchy of Dust Controls

1. Selection of Respirators: Loose-Fitting

PAPRs

2. Protection Factor for Loose-fitting

Powered, Air-Purifying Respirators

E. Guidelines for Determining What is a

Feasible Dust Control

F. Application of Continuous Monitoring

Technology to Prevent Overexposure on

Individual Shifts

IV. Discussion of Proposed Rule

A. Summary

B. Section-by-Section Discussion

V. Health Effects

A. Introduction

B. Hazard Identification

1. Agent: Coal

2. Physical State: Coal Mine Dust

3. Biological Action: Respirable Coal Mine

Dust

C. Health Effects of Respirable Coal Mine

Dust

1. Description of Major Health Effects

a. Simple Coal Workers’ Pneumoconiosis

(CWP) and Progressive Massive Fibrosis

(PMF)

b. Other Health Effects

2. Toxicological Literature

3. Epidemiological Literature

a. Simple Coal Workers’ Pneumoconiosis

(CWP) and Progressive Massive Fibrosis

(PMF)

b. Other Health Effects

VI. Quantitative Risk Assessment

VII. Significance of Risk

VIII. Feasibility Issues

A. Technological Feasibility

B. Economic Feasibility

IX. Regulatory Impact Analysis

A. Costs and Benefits: Executive Order

12866

1. Compliance Costs

2. Benefits

B. Regulatory Flexibility Certification and

Initial Regulatory Flexibility Analysis

X. Other Statutory Requirements

A. Plain Language

B. Unfunded Mandates Reform Act of 1995

C. Paperwork Reduction Act of 1995

D. National Environmental Protection Act

E. Executive Order 12630 (Governmental

Actions and Interference with

Constitutionally Protected Property

Rights)

F. Executive Order 12988 (Civil Justice)

G. Executive Order 13045 (Protection of

Children from Environmental Health

Risks and Safety Risks)

H. Executive Order 13084 (Consultation

and Coordination with Indian Tribal

Governments)

I. Executive Order 13132 (Federalism)

XI. Public Hearings

Appendix A. Derivation of the Critical

Values

Appendix B. References

XII. Regulatory Text

II. Background

Maintaining a work environment free

of excessive levels of respirable coal

mine dust and quartz dust (respirable

dust) is essential for long-term health

protection. Through the joint

promulgation of the single, full-shift

sample and plan verification proposals,

miners would be further protected from

the debilitating effects of occupational

42124 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

1For details, see Quantitative Risk Assessment

and Significance of Risk Sections.

respiratory disease by limiting their

exposures to respirable coal mine dust

to no more than the applicable standard

on each shift.1

Section 202(b)(2) of the Federal Mine

Safety and Health Act of 1977 (Mine

Act) requires each operator to

continuously maintain the average

concentration of respirable dust in the

mine atmosphere, during each shift to

which each miner in the active

workings of such mine is exposed, at or

below 2.0 milligrams of respirable dust

per cubic meter of air (mg/m3). Under

current MSHA regulations, when coal

mine dust contains more than five

percent quartz, the respirable coal mine

dust standard is further reduced, by

means of a formula. Although MSHA

does not currently enforce a separate

standard for respirable quartz dust, the

formula (10 divided by the percentage

quartz) used to establish an applicable

dust standard, in effect, limits quartz

concentrations to 100 μg/m3.

Consistent with the Mine Act and

MSHA regulations, the primary focus of

the federal respirable dust program is on

controlling the concentrations of

respirable dust in the work environment

where miners work or travel through the

application of feasible environmental or

engineering control measures.

Engineering or environmental control of

respirable dust in the mine environment

is the ultimate dust-control technique

and the principal method for protecting

miners’ health. These include all

methods that control respirable dust

levels in the air that a miner breathes by

either reducing dust generation, or by

suppressing, diluting, capturing or

diverting the dust that is being

generated by the mining process. Under

the Mine Act, the mine operator has

primary responsibility for implementing

a program to control respirable dust so

that all miners work in an environment

free of excessive levels of respirable

dust. For full compliance, mine

operators must develop, implement, and

maintain effective engineering or

environmental control measures, and

evaluate them at regular intervals to

assure that they function as intended.

These control measures or ‘‘dust control

parameters,’’ are specified in the dust

control portion of the operator’s mine

ventilation plan currently required

under § 75.370.

Mine ventilation plans are a longrecognized means of addressing health

issues that are mine specific and for

achieving work environments that are

free of excessive concentrations of

respirable dust. Currently, section

75.370 requires each operator of an

underground coal mine to develop and

follow a ventilation plan that is

designed to control methane and

respirable dust in the mine. The plan

must be suitable to the conditions and

mining systems employed at the mine.

Although ventilation plans must be

designed to control respirable dust,

there is no requirement that the plan’s

effectiveness be verified.

The dust control portion of the mine

ventilation plan is a key element of the

operator’s strategy to control respirable

dust in the working environment of

each mechanized mining unit (MMU)

during each shift. Section 70.2 defines

an MMU to mean ‘‘a unit of mining

equipment including hand loading

equipment used for the production of

material.’’ The plans provide a

description of specific engineering

control measures in use. The plans also

contain procedures for maintenance of

specific dust control equipment, such as

scrubbers, dust collectors on roof

bolters, and spray nozzles, or for the

replacement of cutting picks to

minimize dust generation. Once

approved by the District Manager, the

dust control parameters must be

employed on a continuous basis. By

monitoring the parameters, one can be

assured that respirable dust levels are

being adequately controlled without

needing to rely on repeated dust sample

analyses.

Implementing dust control

parameters, which have been

determined effective under typical

mining conditions, and maintaining

these controls in proper working order

provides reasonable assurance that no

miner will be overexposed. Because

technology that continuously monitors

respirable dust and displays dust

concentrations in real-time is not

currently used in underground coal

mines, adhering to effective ventilation

plans is the only practical means of

reasonably assuring, on a continuous

basis, that miners are not overexposed.

In 1996, MSHA implemented revised

ventilation standards which, among

other provisions, required an on-shift

examination of the dust control

parameters before coal production

begins on each MMU. Based on the

recommendations of the MSHA Task

Group (MSHA, 1992), this requirement

is intended to focus attention on the

need for properly functioning dust

controls before production begins. Onshift examinations of dust control

parameters under existing § 75.362 are

important for an effective respirable

dust control strategy.

Recent advances in technology may

make it feasible to continuously monitor

certain parameters such as, air quantity

and velocity, and spray water flow rate

and pressure (Spencer, et al. 1996).

Section 75.362 encourages the use of

such monitors as it would eliminate the

need for periodic physical

measurements of some dust controls to

verify if they are operating properly.

Although current technology allows for

real-time data on the performance, the

condition of key dust control

parameters, and for immediate

modification of controls, MSHA is not

aware of its use by any operator.

Since establishment of the first

comprehensive dust standards in 1969,

the implementation of ventilation plans

by mine operators and their

enforcement by MSHA has had a

significant impact on control of dust

levels in underground coal mines. For

example, based on federal mine

inspector sampling results, the average

dust concentration in the environment

of a continuous miner operator

(occupation code—036) has been

reduced by 86 percent over the past 30

years, from 7.7 mg/m3 to approximately

1.1 mg/m3. This accounts for the

significant decline in the percentage of

operator continuous miner designated

occupation (DO) samples exceeding 2.0

mg/m3, from 49 percent (over 32,000

samples/shifts) in 1971, to 10 percent

(over 2,500 samples/shifts) in 1999.

Analysis of all valid operator DO

samples indicates that in 1971, the 2.0

mg/m3-dust standard was exceeded on

53,463 (44 percent) of the 122,404 shifts

sampled, compared to 3,002 (10

percent) of the 28,727 shifts sampled in

1999 (MSHA, DO Samples by Calendar

Year, 1999). Despite this progress,

MSHA has found evidence that a

significant number of overexposures

still occur on the shifts sampled during

which the approved dust control

parameters are operating at or above

approved levels. This evidence suggests

that it is highly probable that some

miners are overexposed to respirable

dust on shifts not sampled by either the

operator or by MSHA. In addition,

recent medical surveillance data

suggests that miners continue to be at

risk of developing simple coal workers’

pneumoconiosis (CWP), progressive

massive fibrosis (PMF) and silicosis

(Elam, April 1999).

Certain aspects of the current

respirable dust program limit MSHA’s

ability to assure the adequacy of the

dust control parameters under typical

mining conditions according to two

expert panels which reviewed the

federal program designed to prevent

pneumoconiosis among coal miners.

Both the Coal Mine Respirable Dust

Task Group, an interagency task group

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42125

established in 1991 by the Assistant

Secretary for Mine Safety and Health,

and the Advisory Committee on the

Elimination of Pneumoconiosis Among

Coal Mine Workers, established in 1995

by the Secretary of Labor, considered all

aspects of the respirable coal mine dust

control program and made

recommendations for improvement.

A. Coal Mine Respirable Dust Task

Group

In response to concerns about the

Federal coal mine dust program (MSHA,

1992), MSHA’s Coal Mine Respirable

Dust Task Group (the Task Group)

undertook an extensive review of the

program to control respirable coal mine

dust and made recommendations to

improve the program in 1991. As part of

that review, MSHA developed a special

respirable dust ‘‘spot inspection

program’’ (SIP). This program was

designed to provide the Agency and the

Task Group with information on the

dust levels to which underground

miners are typically exposed. Among

other recommendations, the Task Group

recommended that MSHA require mine

ventilation plans to be effective under

typical mining conditions.

The Task Group found that MSHA’s

current program did not promote the

development and implementation of

quality plans. Based on its review of a

representative number of dust control

plans, the Task Group found that some

plans lacked specificity or did not

include all the dust control parameters

actually used. For example, the plans

for three major underground coal mines

listed the air quantity, the primary

means of controlling concentrations of

respirable coal mine dust, to be 18,000

cubic feet per minute (cfm) in the

mining section. The actual quantities

measured by MSHA inspectors at these

mines during the SIP varied from 40,000

cfm to over 120,000 cfm.

Based on a review of MSHA Form

2000–86 (Revised), Respirable Dust

Sampling and Monitoring Data, similar

differences were found between air

quantity specified in approved

ventilation plans and the levels

observed at a number of longwall MMUs

inspected in 1999. For example, 20 of

the 47 longwall MMUs were using

significantly more air than specified in

the ventilation plan (MSHA, September

1999). Under these circumstances, it

would be impossible to assess whether

the air volume specified in the plan was

adequate to maintain dust

concentrations at or below the

applicable dust standard. It should be

noted that air volume quantities, air

velocities, water spray pressures, etc.,

specified in the plan are considered to

be a minimum and MSHA encourages

mine operators to exceed their plan

parameters, but only after the levels

specified in the plan have been shown

to be effective under the conditions in

effect during sampling. In addition, a

lack of specificity in some plans made

it difficult for MSHA inspectors to

determine whether the operator was

complying with the approved plan.

Although several plans indicated that

the mining equipment was to be

provided with water sprays, the plan

did not specify the location of the

sprays or the water pressure at the spray

nozzle.

The Task Group determined that the

use of minimum production levels for

evaluating the effectiveness of dust

control parameters can result in

marginal or inadequate plans. A more

detailed discussion of the impact of

production on the quality of dust

control parameters specified in mine

ventilation plans is provided later in

this document (in sections III.C.1. and

IV.B.). Currently, MSHA relies on

information provided by the operator to

determine at what production level the

plan should be evaluated. No

production records are required for each

MMU. Although operators must submit

production data on a quarterly basis, the

data is compiled for the entire mine. In

addition, these quarterly reports provide

information on the amount of clean coal

produced, which are much lower than

the tonnage of total material produced,

and are not useful for establishing what

constitutes a ‘‘normal production shifts’’

for sampling purposes.

A follow-up survey conducted by

MSHA in 1994 found that 43 percent or

539 of the 1,245 producing MMUs,

worked at least a 9-hour shift. The Task

Group also concluded that current

regulations limiting the duration of

sampling to eight hours do not provide

for adequate assessment of respirable

dust exposure during nontraditional

shifts of more than eight hours.

Implementation of the Task Group

recommendations would have required

regulatory change. The effort to

implement these changes was

suspended pending the

recommendations of Advisory

Committee on the Elimination of

Pneumoconiosis Among Coal Mine

Workers, which was convened in 1995.

B. Advisory Committee on the

Elimination of Pneumoconiosis Among

Coal Mine Workers

On January 31, 1995, the Secretary of

Labor established the Advisory

Committee on the Elimination of

Pneumoconiosis Among Coal Mine

Workers (the Advisory Committee). The

Advisory Committee was chartered to

‘‘make recommendations for improving

the program to control respirable coal

mine dust in underground and surface

mines in the United States.’’ The

Advisory Committee identified and

addressed many of the same issues

considered by the Task Group. Findings

and consensus recommendations were

developed for each issue (MSHA, 1996).

The Advisory Committee concluded

that the dust control portion of the mine

ventilation plan is the key element of an

operator’s strategy to control respirable

dust in the work environment. They

concluded that the initial evaluation,

approval, in-mine verification and

monitoring to demonstrate the

effectiveness of the operator’s proposed

dust control plan is critical for the

protection of miners from lung disease.

Also, believing that the credibility of the

current system of mine operator

sampling to monitor compliance with

exposure limits has been severely

compromised, the Advisory Committee

concluded that restoration of miner and

mine operator confidence in the

respirable coal mine dust sampling

program should be one of MSHA’s

highest priorities. Accordingly, there

was unanimous agreement that in order

to restore confidence in the program

MSHA should take full responsibility

for all compliance sampling currently

being carried out by mine operators

under 30 CFR parts 70 and 90.

The November 1996 Advisory

Committee Report recommended

numerous improvements for the federal

program to protect miners from simple

CWP, PMF, and silicosis. Of these, the

following have been incorporated in this

proposal:

1. MSHA should take full

responsibility for all compliance

sampling at a level which assures

representative samples of respirable

dust exposures under usual conditions

of work without adversely impacting the

remainder of the Agency’s resources and

responsibilities.

2. MSHA should, in consultation with

the operator, perform scheduled

independent dust monitoring to verify

the operator’s plan.

3. MSHA should redefine the range of

production levels which must be

maintained during sampling to verify

the plan. The value should be

sufficiently close to maximum

anticipated production level in order to

reasonably assure that the plan would

be effective under typical operations.

4. MSHA should review compliance

and production records to determine

when there is a need for plan

verification and modification.

42126 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

5. MSHA should require that the

results and monitoring of dust control

parameters and production be recorded

in order to correlate dust control

parameters with dust measurements.

This proposal is intended to eliminate

overexposures on individual shifts and

to restore the confidence of miners and

mine operators in the respirable coal

mine dust sampling program by

addressing the shortcomings identified

by the Task Group and the Advisory

Committee in the current respirable coal

mine dust program. The proposal would

revoke the operator dust sampling

programs under 30 CFR parts 70 and 90

and require the implementation of mine

ventilation plans demonstrated to be

effective in maintaining respirable dust

at or below the applicable standard on

each shift. These ventilation plans

would be verified by MSHA using

single, full-shift respirable dust samples.

The plans’ effectiveness would be

monitored on a regular basis by the use

of inspector single, full-shift samples.

The proposed rule regarding the use of

single, full-shift measurements of

respirable coal mine dust to determine

average concentration is also published

in today’s Federal Register.

MSHA recognizes that the Secretary

of Labor’s Advisory Committee on the

Elimination of Pneumoconiosis Among

Coal Workers made several

recommendations that also impact on

surface coal mine workers. These

surface coal mine issues will be

addressed by the agency in a separate

rulemaking which is currently

underway. The scope of that rulemaking

will include many of the issues that are

addressed in this underground rule

including requirements for duct control

plans, verification of dust control plans

prior to approval, on shift examination

of dust control measures, and the

elimination of operator sampling for

compliance purposes.

III. General Discussion

This section describes the current

respirable coal mine dust program and

the role of mine ventilation plans in

safeguarding the health of miners.

Specifically, this section details:

(1) The reasoning behind MSHA’s

decision to revoke the operator dust

sampling programs under 30 CFR parts

70 and 90 and to take full responsibility

for all compliance sampling;

(2) The proposed procedures for

arriving at an average quartz percentage

that is used to establish an applicable

dust standard under §§ 70.101 and

90.101;

(3) The existing means for evaluating

the effectiveness of dust control

parameters stipulated in mine

ventilation plans;

(4) The plan approval process;

(5) Methods of assuring compliance

with plan requirements; and

(6) MSHA’s efforts to monitor plan

effectiveness on a regular basis.

There is also a detailed discussion of the

hierarchy of dust controls and the

continued need for mine ventilation

plans to specify dust control parameters

in order to preserve the primacy of

engineering controls. Finally, as a

possible alternative to plan verification,

we have included a discussion and a

request for comments on the application

of personal continuous monitoring

technology which is, or may become

available, to prevent overexposure on

individual shifts.

A. Revocation of the Operator Dust

Sampling Program

Under the Federal Coal Mine Health

and Safety Act of 1969 (Coal Act) coal

mine operators were required to take

accurate dust samples at periodic

intervals to measure the amount of

respirable dust in the mine atmosphere

where miners work or travel. The Coal

Act also required that citations be

issued whenever respirable dust

samples collected either by an operator

or by federal mine inspectors showed

noncompliance with the applicable dust

standard. The Coal Act was amended in

1977 (Mine Act), but the respirable dust

provisions remained essentially

unchanged.

1. Pre-1980 Sampling Program

In 1970, federal regulations were

issued that established the first

comprehensive coal mine operator dust

sampling program. Those regulations

required the environment of the

occupation on a working section, or

MMU, exposed to the highest respirable

dust concentration to be sampled—the

‘‘high risk’’ occupation concept. All

other miners working in the MMU in

less risky occupations were assumed to

be protected from excessive

concentrations of respirable coal mine

dust if the high risk occupation was in

compliance. Under the program, each

operator was required to initially collect

and submit ten valid respirable dust

samples to determine the average dust

concentration (across ten production

shifts). If analysis showed the average

dust concentration to be within the

applicable dust standard, the operator

was required to submit only five valid

samples a month. If compliance

continued to be demonstrated, the

operator was required to submit only

five valid samples every other month.

The initial, monthly, and bimonthly

sampling cycles were referred to as the

‘‘original,’’ ‘‘standard,’’ and

‘‘alternative’’ sampling cycles,

respectively. When the average dust

concentrations exceeded the standard,

the operator reverted back to the

standard sampling cycle.

Additionally, each working miner was

sampled individually every 120 or 180

days, depending on the miner’s work

assignment, or every 90 days for each

miner (now referred to as a part 90

miner) who had a positive chest x-ray

for coal workers’ pneumoconiosis

(CWP) and who elected to exercise the

option of transferring to a less dusty

area. However, except for the part 90

miner results, these early individual

sample results were not used for

enforcement, but were forwarded to the

National Institute for Occupational

Safety and Health (NIOSH) to develop a

comprehensive exposure data base for

research concerning black lung disease.

Each sample was accompanied by a

completed mine data card that included,

among other things, the occupation and

social security number of the sampled

miner. This information was also

included in the Agency’s computer

print-out of sampling results that was

sent to mine operators.

2. Post-1980 Sampling Program

In 1980, following hearings held

throughout the coal fields (in 1977 and

1978), regulations governing operator

sampling were substantially revised by

reducing the operator sampling burden,

to simplify the sampling process, and to

enhance the overall quality of the

sampling program. The result was to

replace the various sampling cycles

with a bimonthly sampling cycle and to

eliminate the requirement that each

working miner be sampled. These are

the regulations that currently govern the

mine operator dust sampling program.

Like the 1970 rules, the current

regulations continue to rely on sampling

the environment of the DO in the MMU

that is exposed to the greatest

concentration of respirable coal mine

dust, but reduced the number of shifts

required to be sampled from ten to five.

Other changes included replacing the

requirement that each working miner be

sampled individually with the

bimonthly collection of one sample

from each ‘‘designated area’’ (DA) to

measure the dust concentrations

associated with dust-generating sources

in the active workings of the mine, such

as along haulage ways, at underground

crushers, or at transfer points. These

locations are strategically selected so

that the environment where miners

normally work or travel is monitored for

compliance with the applicable dust

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42127

standard. The operator’s approved

ventilation plan identifies the specific

locations where DA samples are

required to be collected and the dust

control measures used at these

locations. Another change was to

increase the frequency of sampling part

90 miners from every 90 days to one

sample every 60 days.

The revised regulations also

eliminated the reporting of personal

identifiers on the dust data card due to

miner concerns that the data may be

used by mine operators to characterize

the exposure of an individual miner in

future black lung claims. It also

provided for sampling equipment to be

properly maintained and calibrated, and

examined during the shift. Additionally,

operators’ were required to demonstrate

a certain level of competence by passing

a test administered by MSHA. Since

proper use of sampling equipment is

essential to the integrity of the sampling

process, the certification requirement

was intended to provide reasonable

assurance that the person conducting

sampling was competent to perform the

task. After samples have been collected,

certified persons are required to

properly fill out the dust data card that

accompanies each filter cassette. These

samples must then be transmitted

unaltered to MSHA within 24 hours

after the end of each sampling shift, to

expedite compliance determinations

and minimize periods of miner

overexposure.

While not specified in the regulations,

operators are permitted by practice to

note on the dust data card any reason

why they believe the sample(s)

transmitted are not valid and should not

be used by MSHA to determine

compliance. Generally, such samples

are voided by MSHA and the operator

is required to submit a substitute sample

within that bimonthly sampling period.

MSHA may also determine that an

operator sample is invalid for many of

the same reasons. MSHA may also void

operator samples for technical and

administrative reasons, such as samples

submitted in excess of the number

required, or DO samples if they were not

taken during a ‘‘normal production

shift.’’ ‘‘Normal production shift’’ is

defined in existing §§ 70.2(k)(1),

70.207(a) and (d) as a ‘‘production shift

during which the amount of material

produced * * * is at least 50 percent of

the average production for the last set of

five valid samples * * *’’

After MSHA has processed the

samples, the operator is provided with

a report of the sample results, which

must be posted on the mine bulletin

board for a period of 31 days to provide

miners ready access to current

information on respirable dust

conditions in the mine. Operators are

also required to report to MSHA in

writing any change in the operating

status of the mine, mining unit, or

designated area that affects the sampling

requirements, within three working

days after the change occurs.

An operator who is found to be in

violation of the reduced dust standard is

issued a citation and must take steps to

reduce the dust levels. After corrections

have been made, the operator must

collect five additional samples within a

time period specified by MSHA to

demonstrate compliance.

During the development of the 1980

regulations for operator sampling

requirements, we received comments

that indicated a lack of confidence in

our reliance on operator samples for

enforcement purposes. In response to

these concerns, MSHA published a

proposed regulation in 1980 that would

have provided miners’ representatives

the right to observe each phase of the

operator dust sampling process with no

loss in pay. The proposal intended to

promote better cooperation between

mine operators and miners in order to

improve the effectiveness of the

program. In 1985, the Agency decided

not to finalize regulations to provide

miners’ representatives the right to

observe operator sampling, stating that

compliance with the 1980 revisions to

the sampling program had resulted in

greater confidence in the overall dust

program.

3. Issues Affecting the Credibility of

Operator Compliance Sampling

As noted earlier in this proposal,

there is general agreement that

significant efforts have been made

during the past 30 years to reduce dust

levels in our Nation’s mines. While

most mine operators have

conscientiously attempted to sample

miners’ exposure to respirable coal mine

dust as required by regulation, because

of the actions of some, the operator

sampling program continues to be

plagued by allegations of fraudulent

sampling practices. Despite MSHA’s

efforts to improve the quality of the

operator dust sampling program and to

vigorously investigate such allegations

and prosecute violators, sampling

irregularities continue to be

documented involving the physical

alteration of the weight of dust collected

on the filter, or the collection of samples

in low-dust areas of the mine or even

outside of the mine.

The Advisory Committee found that

during the 10 years prior to the

publication of their report, serious

questions had been raised regarding the

representativeness of respirable dust

levels measured by mine operators, the

handling of filter cassettes, and the

changing of work assignments and/or

working conditions during sample

collection. The credibility of the

operator sampling program was

questioned by almost all the

representatives of miners who testified

before the Advisory Committee. Since

1990, more than 160 mine operators,

agents and contractors have pled or

been found guilty of submitting

fraudulent samples to MSHA. These

disclosures correspond with the

concerns expressed by critics of the

operator sampling program.

Detailed reviews of the respirable dust

program by the Task Group and the

Advisory Committee identified aspects

of the current program that have the

potential to negatively affect validity of

sampling results which could impact

miner health protection and,

consequently, its credibility in the

minds of the very people the program

was designed to protect, the miner. For

example, to effectively monitor the mine

environment where miners work or

travel, it is essential that respirable dust

samples are ‘‘representative,’’ in that

they reflect typical dust conditions to

which miners are exposed. The

recurrent pattern of disclosures of

tampering with the sampling process

has highlighted the vulnerability of the

current monitoring system to the

submission of unrepresentative samples.

For example, during the period 1980 to

1990, over 137,000 of the 750,000, or

approximately 18 percent of the

operator DO samples showed extremely

low concentrations (less than or equal to

0.1 mg/m3), compared to 10 percent for

the MSHA samples. Since 1990, 14

percent of the operator DO samples and

3 percent of the MSHA samples were

equal to 0.1 mg/m3.

The fact that sampling is controlled

by the mine operator also allows the

operator to determine when and under

what conditions samples will be

collected during all current bimonthly

and abatement sampling. This permits

the operator to conduct sampling during

those periods in the mining cycle when

conditions are anticipated to result in

lower dust levels in the mine

environment. For example, the operator

may choose to sample during periods

when the volume of air on the MMU is

greatest or when ventilation controls are

operating at optimum efficiently.

Accordingly, these sample results may

not be representative of typical exposure

levels. Other aspects of the monitoring

system that may allow the submission of

unrepresentative samples were reported

by the Task Group in its report of

42128 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

findings. Because some operators do not

sample every bimonthly period or fail to

submit the required number of

bimonthly samples, miners may be

potentially exposed to excessive levels

of respirable dust.

4. Proposed Reforms to the Respirable

Dust Monitoring Program

Believing that one of MSHA’s highest

priorities must be to restore the

confidence of miners and mine

operators in the respirable coal mine

dust sampling program, one of the

Advisory Committee’s key

recommendations was that MSHA take

full responsibility for all compliance

sampling at a level which assures

representative samples of respirable

dust exposure under usual conditions of

work. It also recommended that

compliance sampling should be carried

out at a number and frequency at least

at the level required of operators and

MSHA.

Accordingly, MSHA is proposing to

revoke the operator dust sampling

programs under 30 CFR parts 70 and 90

and to take full responsibility for all

compliance sampling (i.e., bimonthly

and abatement sampling), in a manner

that it believes will be more protective

than the current operator sampling

program. MSHA intends to monitor

miners’ dust exposure and compliance

with the dust control provisions of the

approved mine ventilation plan, or with

the respirable dust control plan for a

part 90 miner at underground mines, in

accordance with the procedures and

guidelines established in Chapter 1 of

the Coal Mine Health Inspection

Procedures Handbook, as modified

herein.

(a) Bimonthly Sampling

MSHA would collect a full-shift

sample from the working environment

of at least five different occupations, if

available, on each producing MMU,

instead of sampling only the DO for five

consecutive shifts or on shifts worked

on five consecutive days as under the

current bimonthly sampling program.

Proposed revised § 70.2(j) defines full

shift, for purposes of bimonthly

compliance sampling, as the entire work

shift including travel time but excluding

any time in excess of 480 minutes. A

full-shift sample would also be collected

from each DA located inby the section

dumping point (i.e., intake air and roof

bolter DAs) bimonthly, and from all

other DAs once each year. All part 90

miners would be sampled bimonthly as

under the current program.

MSHA would issue a citation for

noncompliance when a single, full-shift

measurement demonstrates, at a high

level of confidence, that the applicable

dust standard is exceeded. Although

MSHA would collect multiple

occupational samples from each MMU,

we would issue only one citation on a

single shift on any one MMU unless

more than one dust-generating source

was involved.

(b) Abatement Sampling

Under this proposal, MSHA would

also assume responsibility for all

abatement sampling. As recommended

by the Advisory Committee, MSHA

would utilize single, full-shift samples

to demonstrate abatement. Since the

criteria under which the effectiveness of

ventilation plans are required to be

verified are significantly more stringent

than those for bimonthly sampling,

MSHA does not anticipate issuing many

citations to MMUs and sectional DAs.

However, should an MMU be cited for

violation of the applicable dust

standard, and a determination be made

by the inspector who was onsite that the

dust control parameters are no longer

adequate for the present operating

conditions, MSHA would require the

operator to revise the dust control

portion of the mine ventilation plan

under proposed § 70.219. MSHA would

then verify the effectiveness of the

revised plan. Citations for violating the

applicable dust standard would not be

based on verification sampling.

If on the other hand, a determination

is made that a change in the plan is not

warranted, the operator would take

corrective action to prevent miners from

being exposed on subsequent shifts.

MSHA would then sample the MMU,

similarly to bimonthly compliance

purposes described previously in

paragraph (a) of this section. All five of

the occupational samples taken on a

single shift would have to be below the

applicable standard to demonstrate

abatement. If any sample result exceeds

the applicable standard, but not at a

sufficiently high level of confidence to

warrant a citation, then MSHA may

sample additional shifts or initiate the

plan verification process.

We solicit comments on whether

MSHA should require a higher level of

confidence that the applicable standards

are being complied with before abating

a citation for excessive dust.

Specifically, should abatement

determinations be based on the critical

values specified in § 70.209? We also

solicit comments on whether abatement

sampling should be conducted at or

above the Verification Production Level

(VPL) as defined in § 70.2(aa). Requiring

that abatement be demonstrated under

more typical production conditions, as

represented by the VPL, would provide

assurance that miners will continue to

be protected on a majority of the

production shifts.

MSHA proposes to conduct abatement

sampling involving non-MMU DAs and

part 90 miners in the same way as it

conducts bimonthly sampling. A

violation would be abated if the result

of an abatement sample was less than

the applicable standard. If sample

results exceed the applicable standard

but not at a sufficiently high level of

confidence to warrant a citation, MSHA

may collect additional single, full-shift

samples.

As in the case of MMU abatement

samples, we solicit comments on

whether MSHA should require a higher

level of confidence that abatement

samples for non-MMU DAs and for part

90 miners demonstrate compliance with

the applicable standards before abating

a citation for excessive dust.

Specifically, should abatement

determinations be based on the critical

values specified in § 70.209?

(c) Advantages of MSHA Compliance

Sampling Over Existing Program

According to section 101(a)(9) of the

Mine Act, no health standard

promulgated under this title shall

reduce the protection afforded miners

by an existing mandatory health

standard.

For the reasons listed below, MSHA

believes that, through the joint

promulgation of this proposed rule and

the proposed single, full-shift sample

rule, miners would be further protected

from the debilitating effects of

occupational respiratory disease by

limiting their exposures to respirable

coal mine dust and quartz dust on every

shift.

• Providing and maintaining a work

environment free of excessive levels of

respirable dust is essential for long-term

health protection. While monitoring of

the work environment provides an

indication of how effective the existing

dust control measures are, monitoring

alone does not control dust levels.

Requiring mine operators to implement

and maintain dust control parameters

which, for the first time, have been

determined effective under typical

mining conditions, will provide

reasonable assurance that no miner will

be overexposed on individual shifts.

• Implementing single, full-shift

sample determinations will more likely

detect excessive dust concentrations

and thus protect miners. Averaging

samples taken on multiple shifts can

mask overexposures on individual

shifts. Although MSHA would be

sampling fewer shifts, MSHA believes

the proposed sampling methodology

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42129

2The applicable dust standard for intake air in

§ 70.100(b) and for miners who have exercised

rights under part 90 regulations in § 90.100 is 1.0

mg/m3. Those standards are also lowered if quartz

exceeds 5 percent. However, no effect occurs until

the quartz content exceeds 10 percent.

would provide a more accurate

representation of dust conditions to

which miners are exposed.

• Under the existing operator

sampling program, only the DO is

sampled. Under the proposed program,

MSHA would sample multiple

occupations on the same shift. This

would provide a more comprehensive

assessment of dust conditions to which

miners are exposed.

• Since MSHA will be doing all the

sampling, we will be able to monitor the

dust control parameters and work

practices in effect during sampling. This

will enable MSHA to determine the

effectiveness of the operator dust

control program.

• Unlike the current sampling

program, which allows operators control

over when to sample and under what

operating conditions, MSHA’s visits

will be unannounced. As a result, all

phases of the mining cycle are likely to

be sampled eventually (i.e., construction

activity, longwall start-up, turning

crosscuts, etc.), and samples should be

more representative of typical mining

conditions.

• The miners’ representative will

have walkaround rights during

sampling, thereby increasing miners’

confidence in the dust sampling

program.

B. Procedures for Setting the Applicable

Dust Standard When Quartz is Present

Section 202(b)(2) of the Mine Act and

the implementing MSHA regulations

require each operator to continuously

maintain the average concentration of

respirable dust in the mine atmosphere

during each shift to which each miner

in the active workings of such mine is

exposed at or below 2.0 mg/m3. Under

current MSHA regulations in §§ 70.101,

and 90.101, the applicable coal mine

dust standard is lowered further, by

means of a formula (10 divided by the

percentage of quartz) prescribed by

Secretary of Health, Education, and

Welfare in 1971, whenever the

respirable coal mine dust in the mine

atmosphere of the active workings

contains more than five percent quartz. 2

This is based on the recognition that the

toxicity of coal mine dust increases

when higher levels of quartz are present.

Consequently, as the quartz content of

respirable coal mine dust present in the

mine atmosphere increases over five

percent, the applicable respirable coal

mine dust standard is correspondingly

lowered. For example, if 10 percent

quartz was present, the mine operator

would have to continuously maintain

respirable dust at or below 1.0 mg/m3.

The following provides an overview

of MSHA’s current and proposed

revised procedures for arriving at an

average quartz percentage that is used to

establish an applicable dust standard.

1. Current Procedures

Until 1985, the applicable dust

standard was adjusted based on the

percentage of quartz determined from a

single, full-shift (8 hours or less in

duration) respirable dust sample taken

by an MSHA inspector. Since MSHA

sampled less frequently than we

currently do, a reduced standard could

remain in place anywhere from 12 to 24

months. During that period the level of

quartz could have either increased or

decreased significantly. As a result in

December 1985, MSHA implemented

the procedures in effect. This program,

for the first time, enabled mine

operators to participate voluntarily in

the process of setting reduced dust

standards. These procedures are

contained in Chapter 1 of MSHA’s Coal

Mine Health Inspection Procedures

Handbook.

The most significant program change

involved the use of individual quartz

percentages determined from one

MSHA and, under certain conditions,

up to two coal mine operator full-shift

respirable dust samples, referred to as

‘‘optional samples,’’ to arrive at an

average quartz percentage. It also

provides for the automatic reevaluation

of work areas and occupations on a

reduced dust standard every six months.

Under the existing system, if an

MSHA sample contains more than five

percent quartz, an operator is afforded

the opportunity to submit an optional

sample. Provided it has sufficient

weight gain (0.45 mg), the quartz

content will be averaged with the

MSHA sample when sample results do

not differ by more than ± 2.0 percent,

and the standard set accordingly. If an

operator fails to submit an optional

sample or it contains insufficient weight

for analysis, the standard is adjusted

based on the MSHA sample alone.

Operators are afforded the ability to

submit a second optional sample

whenever sample results differ by more

than ± 2.0 percent. All three results are

then used to compute the average quartz

percentage.

Also, in November 1994, MSHA

refined its analytical procedure enabling

us to analyze inspector low-mass

respirable dust samples (0.100 to 0.449

mg) for quartz. Only those samples

containing 25 micrograms or more of

quartz were used in the standard-setting

process. However, this change applied

only to filters that were preweighed to

0.001 mg for use by MSHA enforcement

personnel. It did not apply to operatorsubmitted optional samples, which were

collected with filters preweighed to 0.01

mg, for which we required a minimum

of 0.45 mg of dust to be analyzed for

quartz. The ability to accurately analyze

samples containing small amounts of

dust reinforced MSHA’s views about the

severity of quartz exposures in some

coal mining operations.

A review of MSHA data for FY 1999

shows that of the 778 entities (i.e.,

MMUs, DAs, designated work positions

(DWPs), roof bolters, and part 90

miners) (MSHA, Results of Quartz

Sampling Operator Involvement, 1999)

placed on an initial reduced standard as

a result of an MSHA sample containing

more than five percent quartz, 753 (96

percent) of the entities submitted an

optional sample. One would expect the

level of participation to be high since

failure to respond would result in the

setting of a lowered dust standard based

on the result of the MSHA sample,

which first triggered the standardsetting process. Of the 753 entities

submitting an optional sample, 231

were afforded the ability to submit a

second optional sample (Ibid.). Again,

as expected, over 73 percent (170) of

those 231 entities submitted a second

optional sample, probably because

doing so could reduce the quartz

average quartz percentage used to

establish the applicable dust standard.

For comparison, in FY 1992, 93 percent

of the operators afforded the

opportunity submitted an optional first

sample, and 82 percent of the operators

given the opportunity submitted a

second optional sample.

However, as the following data show,

operator participation tended to decline

significantly when operators were given

the opportunity to submit samples

involving established entities on

reduced standards. Of the 1122 entities

given the option to submit a sample,

only 450 or 29 percent responded,

compared to 96 percent for entities

placed on an initial reduced standard.

In 1992, 32 percent of the operators

elected to participate.

2. Proposed Revised Procedures

Consistent with MSHA’s decision to

assume full responsibility for

compliance sampling, the Agency is

also proposing to rely only on MSHA

samples as the basis for setting the

applicable dust standard when quartz is

present. As discussed below, while the

proposed scheme reduces the burden

and cost on mine operators to take and

42130 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

3Unlike MSHA’s objective in compliance

sampling, the objective in measuring quartz content

is to establish a reduced standard that will apply

to all shifts. This enables an operator to design a

ventilation plan that will be protective on every

shift. Therefore, it is appropriate to estimate the

quartz content by averaging quartz measurements

obtained over an extended time period.

submit optional samples, it does not

diminish the protections afforded

operators under the current program. It

continues to consider temporal

variability associated with quartz

determinations by averaging three

MSHA samples collected on different

shifts. MSHA recently published a

proposed ‘‘Program Policy Letter (PPL)

on Samples Used to Determine the

Respirable Dust Level When Quartz is

Present’’ for public comment [64 FR

65671, November 23, 1999] whereby the

applicable dust standard would be set

based on the results of multiple MSHA

samples. It proposes that mine operator

samples would no longer be used in

combination with MSHA samples to

determine the average quartz percentage

that is used to set an applicable dust

standard. In the proposed rule, MSHA is

adopting the sampling approach set out

in the PPL. The proposed rule

supercedes the proposed PPL, and

consequently, the proposed PPL is

withdrawn.

We believe that results under the

proposed process will be more

representative of the quartz level to

which miners are exposed. Unlike the

current process, which may cause a

standard to be set based on the quartz

content of a single MSHA sample, three

valid MSHA samples would be used to

set a reduced standard under the

proposed revised procedures [64 FR

65671].3 Since MSHA is sampling

underground mines bimonthly and

surface mines semi-annually, we will

have no difficulty in collecting the

required number of samples to arrive at

the average quartz percentage. If initial

sampling shows that miners may be

exposed to excessive levels of quartz,

MSHA intends to sample at a greater

frequency to ensure that miners are

being protected. This level of sampling

should also allay any operator concerns

regarding the collection of

‘‘misleadingly high’’ samples during

atypical periods. MSHA would also

begin reporting quartz levels to the

nearest tenth of a percent. This is

intended to be more protective for the

miner than the current truncation of

results to a full percentage point.

Under the proposed revised

procedures, when an MSHA sample

contains more than five percent quartz,

we would average the percent of quartz

present in three most recent MSHA

respirable coal mine dust samples to set

the applicable dust standard. If an

MMU, DA, DWP, or part 90 miner is

already on a reduced standard, a new

applicable dust standard will be

established by averaging the results of

the first two MSHA samples taken

under the proposed procedures with the

quartz percentage associated with the

reduced standard in effect. If fewer than

two MSHA samples are taken, the

existing reduced standard will continue

to remain in effect.

Assume an MMU is on a 1.0 mg/m3-

standard (10 percent quartz). If the first

MSHA sample contains 7.2 percent of

quartz, the existing standard of 1.0 mg/

m3 would continue to remain in effect.

If, however, the next sample contains

16.1 percent, the average quartz

percentage would be 11.1 percent

[(10.0% + 7.2% + 16.1%) ÷ 3 = 11.1%],

resulting in a 0.9 mg/m3≤-standard (10

÷ 11.1% = 0.9 mg/m3). For MMUs, DAs,

DWPs, or part 90 miners not on a

reduced standard, MSHA would collect

and analyze three samples for quartz to

determine if a reduced standard was

warranted.

Under the proposed procedures, if the

newly-established standard is lower

than the one in effect, the new standard

would become effective seven days after

the date of the notice informing the

mine operator of the change in the

applicable dust standard. However, if it

is higher than the current standard, the

newly-established dust standard would

become effective on the date of the

notice.

As published elsewhere in today’s

Federal Register, MSHA is also

proposing to take enforcement actions

on the basis of inspector single, fullshift, respirable dust measurements. For

entities on a reduced standard, MSHA

would delay any enforcement action

until the sample is analyzed for quartz.

If an exposure measurement

significantly exceeds the existing

standard and the quartz content of that

sample would cause the standard to be

lowered below the existing reduced

standard, the operator would be cited

for violation of the applicable standard

currently in effect. On the other hand,

if the quartz content of the sample

would cause the dust standard and the

corresponding citation threshold value

(CTV) to increase so that the single, fullshift measurement would no longer

indicate noncompliance, no citation

would be issued. This is illustrated by

way of the following example.

For example, suppose that the MMU

is on a 1.3-mg/m3 standard and a single,

full-shift measurement of 1.6 mg/m3 is

obtained. Since this measurement

exceeds the applicable standard, the

operator is in violation of the standard.

However, analysis of the DO sample

shows that the sample contained 6

percent quartz which, if used, would

result in a 1.7-mg/m3 standard. This

indicates that the quartz level in the

environment of the DO has changed,

suggesting that the current standard may

no longer be valid. Therefore, since the

original measurement of 1.6 mg/m3 is

less than the 1.7-mg/m3 standard that

should have been in effect on the shift

sampled, a citation should not be

issued.

Since MSHA samples are viewed to

be more representative of the respirable

dust concentration to which miners are

exposed, MSHA is proposing to revise

section 70.101 to clarify that the

Secretary will determine the quartz

level by sampling. Operator samples

may no longer be submitted for

determining the applicable standard. It

is our belief that the procedures being

proposed for setting reduced standards

should be more protective for the

miners than those in effect. The

proposed approach provides for

stringent monitoring exposure to quartz

which is consistent with Advisory

Committee’s recommendation that

MSHA increase surveillance and reduce

exposure to this serious health hazard.

As under the current program, if

operating conditions should change

following establishment of a lowered

dust standard that affect the level of

quartz in the working environment,

mine operators or miners’

representatives will be able to request

MSHA to conduct a quartz reevaluation.

In the absence of continuous

monitoring, mine operators should be

cautious in preventing overexposures

when abnormal conditions (such as

cutting rock to install an overcast or

other frequent but short-lived events

involving cutting of rock) are

encountered between MSHA sampling

visits.

3. Validity of Averaging Percentages

The average quartz percentage used to

set the applicable dust standard for a

particular sampling location or area of a

mine is determined in accordance with

accepted mathematical procedures for

arriving at an average value from a set

of values (i.e., adding together the

individual quartz percentages and

dividing by the number of analyses that

are in the set). MSHA believes that this

is the most appropriate method to use.

One commenter who responded to the

PPL (op cit.) contended that MSHA’s

approach of arriving at the average

quartz percentage was mathematically

incorrect. This commenter

recommended that, to more accurately

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42131

reflect the true quartz concentration, the

average quartz percentage be calculated

by dividing total mass of quartz in

micrograms by the total mass of dust

collected (based on three samples in the

example submitted). In the commenter’s

example, the average percentage

obtained using MSHA’s proposed

averaging method was larger than that

obtained using the commenter’s

approach.

The following two scenarios in Table

III–1 clearly demonstrate that MSHA’s

averaging method does not always result

in a larger average quartz percentage

value.

TABLE III–1.—FOR TWO SCENARIOS, USING ALTERNATE METHODS, PERCENT OF QUARTZ IN RESPIRABLE DUST

Scenario I Scenario II

Dust mass SiO2 mass % SiO2 Dust mass SiO2 mass % SiO2

1.7 0.136 8 1.7 0.17 10

1.0 0.04 4 1.0 0.08 8

2.5 0.3 12 2.5 0.15 6

MSHA’s Method Average of % SiO2 = 8 MSHA’s Method Average of % SiO2 = 8

Commenter’s Method Sum (SiO2 Mass) ÷ Sum (Dust Mass) = 9.2% Commenter’s Method Sum (SiO2 Mass) ÷ Sum (Dust Mass) = 7.7%

These examples show that for

situations where MSHA would have

determined a quartz percentage of 8

percent, the commenter’s method would

yield 9 percent in one case and 7

percent in the other.

C. Respirable Dust Control Program for

Underground Coal Mines

The primary focus of the underground

coal mine respirable dust program is to

limit the concentration of respirable

dust to which miners are exposed in the

work environment. To ensure that

miners are not being exposed to

excessive concentrations of respirable

dust, current regulations require mine

operators to:

• Design a mine ventilation plan that

effectively controls respirable dust

under typical mining conditions;

• Implement the plan’s dust control

parameters when approved by MSHA

before commencing production;

• Maintain the dust control

parameters specified in the approved

plan and to monitor their function and

operation through required on-shift

examinations; and

• Evaluate their effectiveness with

bimonthly samples in order to provide

reasonable assurance that the dust

control parameters continue to function

as intended.

To control dust in the work

environment, existing § 75.370 requires

mine operators to develop and submit

ventilation plans that are designed to

control methane and respirable dust in

the mine to MSHA for approval. Each

plan must be suitable to the conditions

and mining system in use at the mine.

These plans provide detailed

requirements for the protection of

miners by specifying engineering

controls. These engineering controls

may include:

• The quantity and the velocity of the

air current used to ventilate the MMU;

• The number, type, and location of

water sprays;

• The pressure and quantity of water

delivered by the sprays; and

• Additional environmental controls,

such as dust scrubbers or devices which

collect mine air and filter out dust

particles.

Plans also contain procedures for

maintenance of dust control equipment

used on the mining machine and roof

bolter. Mine operators frequently do not

fully describe all dust controls in use at

the mine. If such information is not

fully disclosed, it is impossible for

MSHA to fully enforce the plan

provisions and to determine when the

MMU is out of compliance with the

ventilation plan.

When an operator submits a proposed

mine ventilation plan or revision in

accordance with § 75.370, the MSHA

district office reviews it for

completeness and adequacy. The

District Manager will approve the plan

if it meets MSHA requirements, and he

is confident that the dust control

parameters specified will have a

reasonable likelihood of maintaining

dust concentrations within the

allowable limits. Most proposed plans

or revisions are approved immediately,

or tentatively approved, based on

engineering judgement, or experience,

or both, until they are assessed by

MSHA inspector sampling or, to a lesser

extent and only under certain

circumstances, by mine operator

bimonthly sampling. Generally, MSHA

samples within 60 days of plan

approval. Current regulations prohibit a

mine operator from initiating any

mining activity without an approved

ventilation plan. MSHA allows

operators to commence mining by

granting tentative approval. However,

plans may be implemented which are

later determined to be inadequate under

typical mining conditions under the

existing process.

1. Evaluating and Approving Plan

Requirements for Respirable Dust

Control

Under the current program, the

effectiveness of the plan’s dust control

parameters is assessed through sampling

of the DO and other occupations

associated with the MMU. Since there is

no requirement for verifying plan

effectiveness, we have had to rely on

samples that may not be representative

of dust concentrations to which miners

are exposed.

MSHA sampled annually at each

underground mine until recently. The

Agency now samples bimonthly in each

underground coal mine. This increased

sampling effort is part of MSHA’s

initiative to increase confidence in the

federal respirable dust program and to

eliminate simple CWP, PMF, and

silicosis among coal miners. During

sampling inspections, we monitor

compliance with the applicable dust

standard, measure the concentration of

respirable quartz dust; and identify

occupations other than the DO that the

mine operator should routinely monitor

because they are at risk of exposure to

excessive concentrations of respirable

dust.

Under current inspection procedures,

MSHA inspectors sample at least five

different occupations, if available, on

each MMU on each shift. Samples are

normally taken under the mining

conditions in effect during sampling. In

conjunction with this sampling, the

MSHA inspector checks and measures

the dust control parameters early in the

shift to determine whether the

ventilation plan is being followed. The

inspector records the findings, and all

42132 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

the dust controls and work practices in

use during sampling on MSHA Form

2000–86 (Revised), Respirable Dust

Sampling and Monitoring Data. MSHA

will issue a citation if the mine operator

fails to follow any of the dust control

parameters specified in the plan.

Normally, the citation requires

immediate corrective action to abate the

violation. This may involve, for

example, unplugging some water sprays

or increasing the amount of ventilating

air delivered to the MMU. At the

conclusion of the sampling shift for an

MMU, the inspector determines the total

amount of material that was mined (in

tons) during the shift.

If the average concentration of the

samples taken in one shift is less than,

or equal to, the applicable standard, and

the actual production is at least 60

percent of the average production over

the last 30 production shifts, the MSHA

inspector will normally terminate

sampling after the first day and will

recommend that the plan parameters be

approved by the District Manager. This

would occur even if the samples were

found to contain more than 5 percent of

quartz. Such a finding could result in

MSHA lowering the dust standard

below that in effect at the MMU. Since

1985, MSHA has provided mine

operators the opportunity to participate

in the process to establish a lower dust

standard based on the level of quartz.

Mine operators can submit up to two

optional samples which are averaged

with the MSHA sample to determine the

average percentage of quartz which is

used to establish a new dust standard

for the MMU. MSHA published a

proposed Program Policy Letter for

comment (64 FR 65671, November 23,

1999) whereby the standard would be

determined based solely on the results

of multiple MSHA samples. Under that

proposal, mine operator samples would

no longer be used to calculate a reduced

dust standard. Instead, applicable dust

standards will be set based solely on the

results of MSHA samples.

If the average concentration falls

below the standard in effect, but one or

more samples exceed it, no decision is

made regarding the plan’s effectiveness

or regarding compliance with the

applicable standard. Instead, the

inspector must collect additional

samples on subsequent production days

or shifts to establish that the dust

control provisions of the ventilation

plan are adequate.

To a lesser extent, if MSHA is unable

to schedule a mine visit within the

period established by the individual

district, the District Manager may rely

on the results of operator bimonthly

sampling to approve a plan. Generally,

this occurs in the case where a plan is

upgraded with a change which has been

established as effective. MSHA does not

routinely approve plans based on

operator bimonthly sampling because

these samples may be collected during

periods when production is not

reflective of typical production levels.

The current program permits the

operator to submit samples which may

not be representative of normal dust

conditions in the working environment.

Under current regulations, operator

bimonthly samples will be considered

valid, unless voided by MSHA, when

the MMU produces at least 50 percent

of the average level reported for the last

set of five valid bimonthly samples.

Since a mine’s ‘‘normal production’’

level for sampling purposes and the

typical production level may diverge

greatly over the course of several

sampling periods, granting approval

under these conditions may not reflect

the plan’s effectiveness under more

typical mining conditions.

2. Compliance with Plan Requirements

for Respirable Dust Control

Once MSHA determines that the dust

control measures are adequate and

approves the mine ventilation plan, the

specified dust control parameters are to

be employed on a continuous basis to

safeguard the health of miners. Since

maintaining the approved dust control

parameters provides reasonable

assurance that respirable dust can be

controlled, failure to comply with these

requirements would defeat the purpose

of the mine ventilation plan and

needlessly expose miners to excessive

concentrations of respirable dust.

Section 75.362 requires mine operators

to perform an on-shift examination of

the dust control parameters before the

MMU begins production in order to

assure full compliance. Any deficiencies

must be corrected before production

begins.

Compliance with approved plan

parameters is checked during MSHA’s

routine sampling inspections: as part of

six-month plan reviews, during other

non-sampling inspections or

investigations, or in conjunction with an

ongoing sampling inspection.

3. Monitoring Effectiveness of Plan

Requirements for Respirable Dust

Control

Because of the dynamic nature of

mining, conditions can change

significantly in a short period of time.

For example, an increase in the

concentration of respirable quartz dust

will require the applicable standard to

be reduced below the level that was

effective when the dust control

parameters were first evaluated. Such

changes can directly impact the

effectiveness of the dust-control

measures. It is important to regularly

monitor the adequacy of the approved

dust control requirements to ensure that

they remain suitable for the current

conditions at the mine and to determine

whether the plan should be upgraded.

Currently, both MSHA and the mine

operator regularly monitor the

operator’s dust control program.

However, for MMUs the mine operator

is responsible for making sure that all

provisions of the ventilation plan are in

effect on every shift.

(a) Monitoring by Mine Operators.

Since 1980, the current regulations have

required mine operators to take five

valid samples from the DO in each

MMU on a bimonthly basis and submit

them to MSHA for processing, to

determine compliance with the

applicable dust standard. Section

70.207(e) identifies the DO for each

method of mining. These are collected

either on consecutive normal

production shifts, or on production

shifts worked on consecutive days,

during which the amount of material

produced by the MMU is at least 50

percent of the average production

reported for the last bimonthly sampling

period. These samples must be collected

portal-to-portal during the entire shift or

for 8 hours, whichever time is less.

Bimonthly samples have provided a

periodic evaluation of the quality of the

air miners breathe. They also have

provided some insight into the

effectiveness of the operator’s dust

control system on the days in which the

samples are taken. Mine operators may

exceed their minimum plan

requirements once they have been

approved as effective under current

evaluation criteria. Currently, there is

no requirement for mine operators to

record the dust control measures in use

as part of the on-shift examination.

Because there is no requirement for

such records, MSHA cannot assess the

continued adequacy of the approved

dust control requirements unless the

inspector observes the sampling

process.

Although the current operator

sampling program may limit the utility

of bimonthly samples for plan approval

purposes, they allow MSHA to identify

approved plans that may no longer be

suitable to the conditions at a mine. If

multiple individual samples, or their

average, exceed the applicable dust

standard after the required on-shift

examination has been conducted, the

approved plan parameters may no

longer be effective and may need to be

upgraded. If cited, the operator must

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42133

take corrective action to lower the

concentration of respirable dust to

within the permissible concentration as

described in current § 70.201(d). The

operator must demonstrate, through

sampling, that the underlying

condition(s) which caused the violation

has been corrected. Since MSHA

inspectors are not present to observe the

action(s) taken by the operator to abate

the violation, the ventilation plan is

usually not amended to include the

changes the operators make to the

parameters in order to abate the

violation. However, if the operator has

a record of noncompliance and MSHA

determines that the approved plan

parameters may no longer be adequate,

MSHA will notify the operator to submit

an improved plan. Under current plan

approval procedures, if the operator

fails to address MSHA’s concerns after

receiving the second notification,

MSHA will move to revoke the

operator’s mine ventilation plan. If the

plan is revoked, the mine must not

operate.

As discussed earlier, MSHA is

proposing to revoke operators’ sampling

program in underground mines and

assume full responsibility for all

compliance sampling.

(b) Monitoring by MSHA. One of the

objectives of MSHA’s dust sampling

program is to verify that the controls

specified in the approved mine

ventilation plan continue to control

concentrations of respirable dust under

existing mining conditions. As part of

this program, the dust control

parameters must be checked and

measured early in the shift to assure

compliance with the approved plan.

These checks also verify that the

operator is performing the required onshift examinations. Operators have the

opportunity to adjust their dust controls

to reflect that which has been approved

so the plan can be evaluated. However,

most operators choose not to make

adjustments for a number of reasons.

While inspection procedures require the

ventilation plan to include the dust

control measures in use during the

evaluation, most approved plans do not

incorporate all the measures that were

actually in place during MSHA

sampling. This makes it difficult for

MSHA to assess the continued adequacy

of the approved dust control parameters.

Frequently, decisions must be based

only on prior experience or engineering

judgment.

When an operator is cited based on

MSHA samples, the inspector may

require the operator to describe what

type of corrective action will be taken.

However, if a plan change is required,

MSHA must follow similar plan

approval procedures. The operator must

be notified in writing that the plan is

inadequate. In this case, MSHA has

sample results and a record of the actual

parameters in place which can be used

to document the need for a plan change.

Most plans which are revised simply

incorporate only those dust controls that

were in use when MSHA sampled.

MSHA reviews each mine ventilation

plan every six months under § 75.370.

The review includes: all plan revisions,

respirable dust inspection reports,

citations for exceeding the applicable

dust standard, and comments from

representatives of miners. When a

deficiency in the respirable dust control

portion of the plan is found, the MSHA

inspector records comments on MSHA

Form 2000–86. MSHA sends these

results to the mine operator along with

an explanation of whether the operator

must make any changes, the reasons for

the changes, and the date for submitting

a plan revision. MSHA will send a

second notification if the operator fails

to respond. MSHA may revoke the

operator’s mine ventilation plan if the

operator does not comply.

4. Proposed Procedures for Evaluating,

Approving, and Monitoring Ventilation

Plan Requirements

The dust control portion of the mine

ventilation plan is the key element of an

operator’s strategy to control respirable

dust in the work environment, thereby

protecting miners. In recognition of this,

MSHA’s proposal makes a number of

changes to the process for evaluating,

approving, and monitoring mine

ventilation plans, many of which are

based on the Advisory Committee’s

recommendations.

Consistent with the Advisory

Committee recommendations, MSHA

proposes to add provisions to verify the

effectiveness of the ventilation plan in

controlling dust, at a production level

high enough to demonstrate the plan’s

effectiveness under typical operating

conditions. This would require that

MSHA implement procedures for

reviewing compliance and production

records. It would also require that dust

control parameters and production

associated with samples on a given shift

be recorded in order to demonstrate that

parameters specified continue to be

effective in controlling dust.

This proposal would require a

ventilation plan to include all

engineering or environmental controls

necessary for maintaining dust

concentrations at acceptable levels. A

plan must also include any specific

work practices or other means used to

supplement these controls in order to

minimize the dust exposure of

individual miners. Unlike plans under

the current program, you would have to

identify all measures necessary for

achieving continuous compliance with

the applicable dust standard in the plan.

MSHA proposes to require you to

include information on the length of

each normal production shift in

§ 75.371(f) and to specify the VPL as

defined in § 70.2 in every ventilation

plan. The VPL is the tenth highest

production level recorded in the most

recent 30 production shifts. This value

will represent the minimum production

level at which effectiveness of the plan

must be demonstrated.

We believe that the production

criteria used to evaluate plan

effectiveness may not adequately

represent typical conditions under

which miners work. Requiring that

plans be verified at or above the VPL

would provide assurance that excessive

dust concentrations will be avoided,

even on shifts with higher-than-average

production. This is more protective of

miners than the current practice of

evaluating plan adequacy based on

MSHA inspector samples taken when

production can be as low as 60 percent

of the average production.

MSHA would require you to maintain

records of the amount of material

produced by each MMU during each

shift. This would enable you to establish

the VPL. Because verification of a plan’s

effectiveness is conditioned on the VPL,

these records are necessary to ensure

that the VPL continues to represent

higher-than-average production.

Although a VPL would be included in

the ventilation plan, MSHA would not

cite you for producing at levels

exceeding the VPL.

Under the proposed plan verification

procedures, MSHA will notify you of

when we intend to initiate verification

sampling. To enable MSHA to evaluate

the effectiveness of the plan parameters

at or above the VPL, you must make

sure that all the dust control parameters

specified in your ventilation plan are

fully implemented. On the date

scheduled for verification sampling, you

should arrange to be producing at or

above the VPL specified in the plan,

using only the dust control parameters

and other measures listed in the plan.

Under the proposal, MSHA would

perform the sampling necessary to

verify your plan. We will collect fullshift samples from the work

environment of multiple occupations on

each MMU, including the DO. We will

collect all samples in accordance with

procedures described in Chapter 1 of

MSHA’s Coal Mine Health Inspection

Procedures Handbook (op cit.). In

addition, on every shift on which we

42134 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

4MSHA believes that under the guidance of the

Interpretive Bulletin 43 FR 17546 (April 25, 1978)

these rights arise when: (1) an ‘‘inspection’’ is made

for the purposes set forth in section 103(a), and (2)

the inspector is physically present at the mine to

observe or monitor safety and health conditions as

part of direct safety and health enforcement

activity.

Verification sampling is necessary to obtain

information related to approval of the mine’s

ventilation plan and whether coal mine dust will

be adequately controlled to protect miners health.

Consequently, miners and their representative

would have the right to accompany the inspector

with no loss of pay for the time during which the

representative exercises this right. However, this

right is limited by Section 103(f) to only one such

representative of miners.

collect verification samples, we would

measure and record all of the

quantitative engineering or

environmental parameters. We would

also record any other means used to

reduce miners’ dust exposure on the

sampled shift. We will provide you with

this information, along with verification

sample results, for posting on your mine

bulletin board.

In accordance with section 103(f) of

the Mine Act, you must provide miners

and their representatives the same

walkaround rights during plan

verification sampling as they are

provided during any other physical

inspection made pursuant to the

provisions of section 103(a) by an

authorized representative of MSHA.4

Unlike the existing program, the

proposal would allow you, for the first

time, to use either approved PAPRs or

verifiable administrative controls to

supplement your engineering or

environmental controls for compliance

purposes at longwall mining operations.

This would be permitted only on an

interim basis and only after MSHA

determined that you had exhausted all

feasible engineering or environmental

controls.

Finally, under this proposal, MSHA

has established rigorous criteria for

determining when to approve a plan.

We would approve a plan only when a

sufficient number of verification

samples demonstrate, at a high level of

confidence, that the plan is effective at

production levels at or above the VPL.

D. Hierarchy of Dust Controls

Consistent with the Mine Act,

engineering or environmental controls

have been the principal method used for

preventing or minimizing miners’

exposure to these primary and

secondary dust sources in the workplace

over the past 30 years. Control of dust

throughout the work environment gives

reasonable assurance that all miners in

the area will be adequately protected.

Well-designed engineering or

environmental controls provide

consistent and reliable protection to all

workers because they are not dependent

upon constant human supervision or

intervention, except for the periodic

checks, to insure that they are

functioning as intended. MSHA requires

mine operators to utilize all feasible

engineering or environmental controls,

which are specified in the mine

ventilation plan, to maintain

concentrations of respirable dust in the

work environment of MMUs at or below

the applicable dust standard.

Engineering or environmental controls

include all methods that control the

level of respirable dust by reducing dust

generation (e.g., machine parameters) or

by suppressing (e.g., water sprays,

wetting agents, foams, water infusion,

etc.), diluting (e.g., ventilation),

capturing (e.g., dust collectors) or

diverting (e.g., shearer clearer, passive

barriers, etc.) the dust being generated

by the mining process. The importance

of using engineering or environmental

controls was not only recognized by the

Advisory Committee, but also by NIOSH

in its criteria document: Occupational

Exposure to Respirable Coal Mine Dust

(NIOSH, 1995), when it recommended

that such controls must continue to be

relied upon as the primary means of

protecting coal miners. The primacy of

engineering or environmental controls is

preserved under this proposal. The

proposal requires mine operators to

utilize all feasible engineering or

environmental controls to reduce

concentrations of respirable dust to a

level at or below the applicable

standard.

Administrative controls are another

method of avoiding overexposure.

Administrative controls refer to work

practices that reduce miner’s daily

exposure to respirable dust hazards by

altering the way in which work is

performed. They consist of such actions

as rotation of miners to areas having

lower dust concentrations, rescheduling

of tasks, and modifying work activities.

The Task Group found that

administrative controls were used

increasingly, even when it was feasible

to implement additional engineering or

environmental controls. The use of

administrative controls was found to be

increasing at mines employing longwall

mining systems. The most frequent

administrative control in use consisted

of restricting the activities of miners

required to work downwind of the

longwall operator, or the occupation

designated as 044 by MSHA. This

particular form of administrative control

is in use at some of the 51 longwall

MMUs that were operating on October

28, 1999. MSHA has observed the use of

this particular administrative control,

even after changing the location of the

DO from the 044 to the 060

occupation—the miner who works

nearest the return air side of the

longwall working face. Unlike

engineering or environmental controls,

to be effective, administrative controls

rely on the ability of miners to follow

specified procedures. However,

difficulty in ensuring that miners adhere

to the administrative controls, labor/

management agreements, and

limitations on the number of qualified

miners capable of handling specific

tasks may limit the use and

effectiveness of such controls. The

Advisory Committee Report states that

the use of administrative controls does

not reduce the operator’s responsibility

to maintain ambient dust levels in

active workings at or below the

standard. However, the Advisory

Committee noted that ‘‘while not a

substitute for engineering controls,

administrative controls, which restrict

the amount of time that miners spend in

an area with uniform exposure level,

can result in lower personal exposures

(MSHA, 1996).’’

Under the Mine Act and current

regulations, mine operators are required

to make approved respiratory

equipment available to all affected

underground miners whenever exposure

to concentrations of respirable dust

exceeds the applicable dust standard.

However, miners are not compelled to

use them. While required for interim

protection, mine operators cannot use

respirators as a substitute for

engineering or environmental control

measures. Engineering or environmental

controls have been found to provide

more consistent and reliable protection

to all workers. In comparison to

respirator programs, the effectiveness of

engineering or environmental controls

does not rely heavily upon constant

supervision or miners’ consistent and

correct use of the equipment.

Furthermore, we can measure dust

concentrations to which miners are

exposed when engineering or

environmental controls are in use. It is

more difficult to monitor the

effectiveness of a respirator program

because the assessment methods are

indirect. For these reasons, MSHA’s

longstanding policy has been that

respirators should be used in

underground coal mines only as an

interim method of protection until

feasible engineering or environmental

controls are available.

Approved respirators are not

acceptable substitutes for feasible

engineering or environmental controls.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42135

5References to specific equipment, trade names

or manufacturers does not imply endorsement by

MSHA.

It is MSHA’s position that technology

is available to control respirable dust to

at or below the applicable standard at

MMUs employing continuous and

conventional methods of mining.

However, MSHA recognizes that, unlike

other mining systems, longwall MMUs

may have acute dust problems caused

by the face-ventilation airstream

carrying the shearer-generated face dust

over the miners working along the face

downwind of the shearer operator

(occupation code 044). This makes it

more difficult to control the work

environment on a consistent basis.

Improvements in dust control

technology have not kept pace with

increases in production technology

associated with high-production

longwall MMUs. Average longwall shift

production reported during bimonthly

sampling has increased more than fivefold since 1980, from approximately 890

tons per shift (tps) to more than 4,900

tps in 1998. In fact, 49 percent of the

shifts sampled averaged 4,000 to 8,000

tps, while approximately 8 percent of

the shifts exceeded 8,000 tps. A major

milestone in mining history was

achieved in 1997, when a single

longwall mine produced more than 1

million tons of coal in a single month

(Fiscor, 1998).

Unfortunately, as more coal is mined,

greater quantities of respirable dust are

generated. The increase in longwall

production levels has resulted in the

generation of far more dust which must

be controlled (Webster, et al., 1990;

Haney, et al., 1993; O’Green, 1994).

According to published literature,

several thousand milligrams of

respirable dust per ton of coal cut can

be formed and liberated during the

cutting process (National Research

Council, 1980). Of course, the quantity

of respirable dust produced by the

cutting process can vary greatly,

depending on the type of coal, its

moisture content, the amount of rock

bands in the coal, sharpness of the

cutting bits, the particular mining

machine, and many other factors.

Although a considerable amount of

respirable dust is formed by the cutting

operation, most of these particles do not

become airborne. Nevertheless, given

the amount of dust that is produced per

ton of coal mined, a larger quantity of

respirable dust would be generated from

cutting 8,000 tons of coal than from

cutting 4,000 tons. An operator is not

required to produce, on a sampled shift,

more than 50 percent of the average

production reported during the last

bimonthly period. Therefore, dust

concentrations on sampled shifts may

be substantially lower than what is

typical and therefore not reflect the dust

exposure on that shift.

While significant efforts have been

made to implement available control

technology, no significant new

advancements in longwall control

technology have been reported since

1989 (U.S. Bureau of Mines, undated).

From 1989 to 1999, the percentage of

operators’ longwall DO samples

exceeding 2.0 mg/m3 dropped from 34

percent to 20 percent, reflecting the

impact of the implementation of those

advances in longwall control

technology. Although this represents a

significant improvement, especially in

view of the five-fold increase in average

shift production, the 1999 data clearly

show that miners continue to be

overexposed on a significant number of

shifts.

Over the past ten years, MSHA and

the former U.S. Bureau of Mines, now

part of NIOSH, have made unsuccessful

efforts to conduct a joint research

program that would evaluate the

effectiveness of available longwall dust

control technology. The objective of

such research would have been to

quantify the effects of employing all

state-of-the-art dust-control technology

available for a longwall operation.

Unfortunately, such a study has never

been undertaken because no industry

partner has agreed to participate. Based

on our experience, MSHA’s position

remains that feasible engineering and

environmental controls exist for

maintaining dust exposures at or below

the applicable standard, even at

longwall operations. MSHA has

concluded that the proposed plan

verification process will lead to further

improvements in the design and quality

of mine ventilation plans. At some highproducing longwall MMUs, however,

the engineering or environmental

controls available may not succeed in

sustaining continuous compliance with

the applicable dust standard at certain

locations downwind of the longwall

operator (occupation code—044).

Mining industry representatives have

repeatedly urged MSHA to accept the

use of powered, air-purifying respirators

(PAPRs) (e.g., Racal Airstream

helmets),5 as an alternative means of

complying with the applicable dust

standard when engineering or

environmental controls failed or were

not feasible. The Airstream helmet

originated in the early 1970s at the

Safety in Mines Research Establishment

in England which developed it

primarily for mining use to provide

protection for head, eyes, and lungs in

a single convenient unit. Because these

devices provide a continuous stream of

filtered air over the miner’s face, it has

been suggested that they be viewed as

miniature environmental controls,

rather than respirators. In September

1997, Energy West Mining Company

(Energy West) petitioned the Secretary

of Labor to amend the mandatory health

standards for underground coal mines at

30 CFR part 70 to allow Airstream

helmets or other types of PAPRs to be

used as a supplemental means of

complying with the applicable dust

standard. The petition for rulemaking

proposed that the Secretary issue a

standard which would supersede the

current interim statutory standard,

specified in Section 202(h) of the Mine

Act. Energy West contended that PAPRs

are necessary as a supplemental means

of controlling respirable dust because

even the most diligent application of

feasible engineering/environmental

controls could not always prevent

overexposure. MSHA has consistently

acknowledged that PAPRs can be

effective as an interim method of

protecting miners when properly

selected, used, and maintained.

However, MSHA has never considered

the Racal Airstream helmet (or the

3MTM AirstreamTM Helmet-Mounted

PAPR), or any other respiratory

protective device approved and labeled

as such by the National Institute for

Occupational Safety and Health

(NIOSH), to be an engineering,

environmental, or administrative

control. Hence, it cannot be used as an

environmental control to comply with

the respirable dust standard.

In order to provide the greatest

possible protection for all miners under

typical mining conditions, MSHA is

proposing to permit, under certain

circumstances, the limited use of either

approved loose-fitting PAPRs or

verifiable administrative controls for

compliance purposes. This would

provide you with the flexibility to select

the most appropriate option for

supplementing your engineering or

environmental controls. We believe that

permitting longwall mine operators to

use loose-fitting PAPRs or verifiable

administrative controls for compliance

purposes will not reduce the level of

protection afforded longwall miners by

the existing standard.

This aspect of the proposal is limited

to longwall mine operations because

technology is available to control

respirable dust at or below the

applicable standard at MMUs

employing continuous and conventional

methods of mining. Their use at

longwall operations would be permitted

42136 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

6 7Quantitative fit testing and qualitative fit

testing are methods used to determine the facepiece

seal and fit of a tight-fitting respirator.

only after MSHA determines that for a

specific MMU, excessive dust

concentrations cannot be prevented in

the environment of miners required to

work downwind of the longwall shearer

operator (occupation code—044) by

implementing all feasible engineering or

environmental controls. We solicit

comments concerning the availability of

feasible engineering or environmental

controls to lower dust levels.

1. Selection of Respirators: Loose-Fitting

PAPRs

Loose-fitting PAPRs completely

surround the head and cover the face

with a full visor or shield. The

functional and physical characteristics

of loose-fitting PAPRs as described

below make them especially well-suited

to underground coal mining conditions,

and it is for these reasons that MSHA

determined that loose-fitting PAPRs are

the most suitable type of respirator

protection for these conditions.

A loose-fitting PAPR protects the

wearer from excessive levels of

respirable dust by providing a

continuous flow of filtered air and

imposing minimal breathing resistance

upon the wearer. Loose-fitting PAPRs do

not require fit-testing,6 7 unlike tightfitting respirators. Furthermore, it is not

necessary to be clean shaven for this

type of PAPR to be protective.

Loose-fitting PAPRs provide safety

advantages over other forms of PAPRs or

tight-fitting respirators. In addition to

protecting the lungs, the helmet and

visor of a PAPR can simultaneously

protect the eyes and head from highvelocity nuisance dust, spray, and small

pieces of coal from the cutting drums

and face and from loose coal falling

from the roof. Loose-fitting PAPRs

provide easier communication between

miners, rather than the muffled

communication between workers which

is experienced between miners wearing

tight-fitting facepieces.

The Racal Airstream helmet has

been in use in underground coal mines

since the late 1970s. Over 50 percent of

the longwall mines operating have

miners who wear Airstream helmets for

added protection. This respirator was

developed primarily for mining use by

the Safety in Mines Research

Establishment (SMRE) in England. It

combines face, head, and respiratory

protection in a single convenient unit.

The support hardware which provides

the filtered air is packaged in the

helmet. Power for the system is

provided by a belt-mounted battery.

Dusty air enters the helmet through a

rear entrance port, passes through a prefilter assembly that removes the coarse

material, and then passes through the

fan and into a final-filter assembly that

is located between the head of the

wearer and the outer helmet shield. The

filtered air then sweeps down across the

wearer’s face, behind the face-shield

visor, and exits at the chin. Soft plastic

seals join the face-shield visor to the

sides of the head and jaw limiting entry

of unfiltered mine air (Greenough,

1979). The original Airstream helmet

has undergone numerous design

improvements since it was first

introduced in British coal mines in the

mid 1970s. The Airstream helmet is

produced by 3M (3MTM HelmetMounted AirstreamTM series).

2. Protection Factor for Loose-fitting

Powered, Air-Purifying Respirators

The type and degree of protection of

any respirator depends on the ability of

a respirator to prevent hazards from

entering the worker’s breathing zone. In

an underground coal mine, the level of

protection afforded by a loose-fitting

PAPR to protect a miner depends on the

type and condition of the filter material

of the air-purifying element, the nature

and concentration of the respirable coal

mine dust, proper maintenance of the

PAPR and battery pack, and especially,

how consistently the miner properly

wears the PAPR, including having the

visor properly lowered. The protection

factor, the ratio of the respirable dust

concentration outside the respirator to

the concentration inside, measure how

much protection a respirator might

provide to the wearer.

In the NIOSH Respirator Decision

Logic (May 1987), based on simulated

laboratory tests and some workplace

protection tests (none of which

replicated conditions in underground

coal mines) NIOSH assigned loosefitting, helmeted PAPRs, properly worn,

a protection factor (APF) of 25. NIOSH

made the following cautionary

statement:

Despite the fact that some of the PF’s

[APFs] have a statistical basis, they are still

only estimates of the approximate level of

protection. It must not be assumed that the

numerical values of the APF’s presented in

this decision logic represent the absolute

minimum level of protection that would be

achieved for all workers in all jobs against all

respiratory hazards. The industrial hygienist

or other professional responsible for

providing respiratory protection or

evaluating respiratory protection programs is

therefore encouraged to evaluate as

accurately as possible the actual protection

being provided by the respirator (NIOSH,

May 1987).

Furthermore, in its Guide to Industrial

Respiratory Protection (September

1987), published after the NIOSH

Respirator Decision Logic, NIOSH

offered an additional caveat with regard

to the effectiveness of PAPRs:

Until recently, powered air-purifying

respirators were considered positive pressure

devices. Field studies by NIOSH as well as

others, have indicated that these devices are

not positive pressure, and that their assigned

protection factors are inappropriately high

(NIOSH, September 1987).

There is virtually no positive pressure

in the PAPR. Respirable dust may

invade the miners’ breathing zone

through openings along the side and

bottom of the visor, even when it is

maintained in the full lowered position.

The extent to which respirable dust

invades a miner’s breathing zone,

depends, in part, on the MMU’s

ventilation air velocity and on the

miner’s work rate and his angle of

orientation to the airflow.

Questions have arisen concerning the

applicability of NIOSH’s APF of 25 for

loose-fitting PAPRs to some work

environments. It has been contended

that NIOSH overestimates the minimum

level of protection provided in the

workplace even when used within the

context of a good respirator program

(Myers, et al., 1984). The environmental

conditions assumed in NIOSH’s

estimation of the APF for loose-fitting

PAPRs are not consistent with those in

underground longwall mining

operations. For example, various unique

conditions of coal mining (obstructed

views and difficulty communicating)

may compel miners to lift their visors.

Once the visor is raised, the respirator

is no longer being worn in accordance

with conditions required for an APF of

25. Also, the high velocities of air

customarily found on longwall mining

faces, are not comparable to the air

velocities experienced in most industry

sectors nor in those represented in the

studies used to determine the APF of 25.

The actual fit or seal of the respirator

helmet to the wearer, repeated worktask motions in confined work spaces,

raising the visor, and high air velocities

along the longwall face all may

significantly reduce the actual degree of

protection provided in the workplace.

Unlike an APF, an effective protection

factor (EPF) reflects the protection

provided by a respirator over an actual

work shift given specific occupational

environmental conditions such as

ventilation velocity, when the wearer

performs typical work activities and

uses the respirator in a typical manner.

Laboratory and in-mine studies (EPF

studies) show that mine ventilation air

flow or velocity, the primary means

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42137

longwall operators use to control

respirable dust levels, may be the single

biggest factor affecting the level of

protection provided by the PAPR on a

longwall mining face. Cecala, et al.,

(1981) found protection of loose fitting

PAPRs (Racal Airstream helmets) to be

inversely related to ambient air velocity

in both laboratory and in-mine settings

(Ibid). In other words, increased air

velocity leads to decreased effectiveness

of the PAPR.

The level of protection from a loosefitting PAPR is also affected by the

orientation of the helmet to the airflow.

Cecala’s wind tunnel tests clearly

showed that, at the higher flow rates,

helmet efficiency was greatest when

facing directly against the airflow and

was reduced when the helmet was

oriented in other directions. This is

extremely important since miners are

more likely to orient their heads at an

angle to the airflow, or to face

downwind, than to face directly into the

airflow.

Cecala’s in-mine testing of the loosefitting, helmeted PAPRs produced an

EPF confirming the inverse relationship

between wind speed and the level of

protection provided by PAPRs shown

during wind tunnel testing. Air velocity

in underground mines is measured in

units of feet per minute (fpm). Under

normal face-velocity conditions (less

than 400 fpm), the Airstream helmet

averaged a respirable dust reduction of

84 percent, which is equivalent to an

EPF of 6.4. However, under high facevelocity conditions (1,200 fpm), the

helmet’s dust reduction efficiency

decreased significantly, averaging only

49 percent, which is equivalent to an

EPF of 2.

Other researchers have reported that

helmeted PAPR systems are vulnerable

to inward leakage into the wearer’s

breathing zone (Howie, et al., 1987;

Sherwood, 1991). For example, Howie,

et al., found that increasing airflow

velocities from approximately 400 to

800 fpm doubled the inward leakage of

the helmet when the airflow impinged

on the wearer’s head only, and

increased the leakage further when the

airflow impinged on the wearer’s body

and head (Howie, 1987). Subsequent

testing of a redesigned unit at a wind

velocity of approximately 700 fpm

showed decreased inward leakage,

yielding a protection factor of 6.3. This

met the target protection factor of 5,

which was subsequently proposed by

the European Community to be the

standard for powered helmet

respirators.

More recent studies conducted by

Bhaskar, et al. (1994) at four mediumvelocity western longwalls indicated

loose-fitting PAPRs had an average dust

reduction efficiency of 83.8 percent

(Ibid.). Although a different sampling

procedure was used, this result is

consistent with the average value of 84

percent obtained by Cecala, et al., under

normal mine face-velocity conditions.

During the test period, the headgate

velocity ranged from 345 to 500 fpm,

with approximately 88 percent of the

recorded velocities falling below 500

fpm. The tailgate velocities ranged from

280 to 550 fpm and only one exceeded

500 fpm. No tests were conducted under

high mine face-velocity conditions.

The headgate and tailgate velocities

observed by MSHA inspectors at 55

longwall MMUs were reviewed in 1999.

The headgate and tailgate velocities

ranged from 365 to 1,645 fpm and from

200 to 1,400 fpm, respectively. More

importantly, headgate velocities at 60

percent of the MMUs exceeded 500 FPM

and some 18 percent exceeded 800 fpm.

Approximately 55 percent of tailgate

velocities exceeded 500 fpm and 11

percent exceeded 800 fpm.

PAPRs have been demonstrated to be

effective on longwall MMUs when air

velocities do not exceed 500 fpm, but,

as described above, there is evidence

that their effectiveness is reduced when

air velocities are increased. Therefore,

given the range of observed longwall

face air velocities to which miners are

exposed and the proposed requirement

that the verified ventilation plan

demonstrate that the longwall shearer

operator (occupation code—044) be at or

below the applicable standard, MSHA is

proposing to grant a protection factor of

two for loose-fitting PAPRs used under

this proposal. Multiplying either the

respirable dust standard or the

verification limit (whichever is

applicable) by the protection factor

yields the maximum concentration of

respirable dust against which a

particular type of respirator can be used.

In other words, if MSHA permits a

longwall operator to use PAPRs, then

the maximum concentration of

respirable coal mine dust and quartz

dust against which these particular

respirators can be used are 4.0 mg/m3

and 200 μg/m3, respectively. A complete

respiratory protection program is

required to assure that a respirator’s

protective value is not compromised by

improper fitting or usage.

MSHA’s determination is based on

the best scientific and technical

information available as well as sound

engineering judgment. However we

encourage you to submit comments on

the protection factor. We are

particularly interested in obtaining more

recent data that may be available

concerning protection factors as well as

the conditions for the use of PAPRs. If

you believe MSHA should establish a

different protection factor, please

submit these data supporting your

position.

E. Guidelines for Determining What Is a

Feasible Dust Control

The proposal would require a mine

operator to implement all feasible

engineering or environmental controls

that are technologically and

economically feasible. The Federal Mine

Safety and Health Review Commission

(Commission) has addressed the issue of

what MSHA must consider, when

determining what is a feasible control

for enforcement purposes. In cases

involving the noise standard for metal

and nonmetal mines, the Commission

has held that a control is feasible when

it: (1) reduces exposure, (2) is

economically achievable, and (3) is

technologically achievable. See

Secretary of Labor v. Callanan

Industries, Inc., 5 FMSHRC 19 00

(1983), and Secretary of Labor v. A. H.

Smith, 6 FMSHRC 199 (1984).

In determining technological

feasibility of an engineering control, the

Commission has ruled that a control is

deemed achievable if through

reasonable application of existing

products, devices, or work methods

with human skills and abilities, a

workable engineering control can be

applied to the exposure source. The

control does not have to be ‘‘off-theshelf’’ or already available but, it must

have a realistic basis in present

technical capabilities. Further, the

Commission has held that MSHA must

assess whether the cost of the control is

disproportionate to the ‘‘expected

benefits,’’ and whether the cost is so

great that it is irrational to require its

use to achieve those results. The

Commission has expressly stated that

cost-benefit analysis is unnecessary in

order to determine whether an

engineering control is feasible.

According to the Commission, an

engineering control may be feasible

even though it fails to reduce the

exposure to permissible levels in the

standard, as long as there is a significant

reduction in exposure.

Consistent with the Commission case

law, MSHA would consider three

factors in determining whether

engineering or environmental controls

are feasible at a particular mine: (1) the

nature and extent of the overexposure;

(2) the demonstrated effectiveness of

available technology; and (3) whether

the committed resources are

disproportionate to the expected results.

As explained in the discussion of

proposed § 70.211 in Section IV of the

42138 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

proposal, the formal determination of

whether all feasible engineering or

environmental controls have, in fact,

been implemented at a specific mine to

prevent excessive dust concentrations

would be made by the Administrator for

Coal Mine Safety and Health based on

the best available information,

experience, and engineering judgment.

F. Application of Continuous

Monitoring Technology to Prevent

Overexposures on Individual Shifts

Because approved technology that

continuously monitors respirable dust

and displays dust concentrations in

real-time is not available, effective

ventilation plans remain the only

practical means to provide reasonable

assurance, on a continuous basis, that

miners are not overexposed on

individual shifts. However, MSHA

recognizes that person-wearable

continuous respirable dust monitors

under development may lead to

significant improvements in monitoring

the work environment in order to

improve miner health protection. In an

effort to reduce occupational respiratory

disease among underground coal

miners, MSHA encourages mine

operators to adopt new and better dust

monitoring technology as part of the

approved ventilation plan.

Unlike the current monitoring system,

which relies on periodic sampling and

requires that corrective action be taken

after the necessary delay in obtaining

dust level information, continuous

monitoring would allow mine operators

and miners to be aware of the actual

dust conditions at all times, thereby

enabling immediate action to avert

possible overexposure. The ability to

monitor dust exposure continuously

during the shift, predict end-of-shift

cumulative exposures, and to display

the actual end-of-shift exposure would

be far more effective in preventing

simple CWP and PMF than the current

system.

The health benefits of continuous

monitoring were clearly recognized by

both the Task Group and the Advisory

Committee. Both recommended

development, field testing, and

immediate deployment of such monitors

for a variety of purposes. The Task

Group concluded that continuous

monitoring of the mine environment

and dust control parameters offered the

best long-term solution for improving

the existing federal program designed to

prevent simple CWP and PMF among

coal miners. Similarly, the Advisory

Committee stated in its report that:

Worker exposure to excessive levels of dust

can be prevented by implementing a hazard

surveillance program that provides mine

personnel with current information on actual

dust levels in the work environment at all

times, and on the status of key dust control

parameters. The availability of this

information on a real-time basis would

enable mine personnel to focus attention

immediately on the need to adjust control

parameters to avert possible overexposure.

The recent development of continuous dust

and continuous dust control parameter

monitors, which have both direct reading and

data recording/processing capabilities, offers

the potential to improve monitoring of the

work environment significantly and

contribute to the effective control of

exposure. (MSHA, 1996).

MSHA has sought a means to measure

the concentration of respirable coal

mine dust in coal mines on a

continuous basis for nearly two decades.

Beginning in the 1970’s, at the request

of MSHA, the former U.S. Bureau of

Mines funded several developments of

fast-response, direct-readout respirable

dust monitors for measuring the

concentration of respirable dust.

One type of fast-response respirable

dust monitor determined the mass of

respirable dust particles collected on a

grease-coated disk by the attenuation of

beta radiation caused by the dust spot

on the impaction disk. The unit was

capable of operating for long periods,

taking up to 450 1-minute samples, and

printing the individual and timeintegrated concentrations on a tape.

Other devices have used lightscattering technology to measure and

provide an immediate direct readout of

dust concentrations. Since light

scattering is often dependent on particle

characteristics such as size, surface

properties, and refractive index, this

type of dust monitor does not measure

a mass concentration directly and can

provide only a relative measurement.

However, it can be calibrated in the

laboratory to give an approximate mass

concentration.

The light-scattering technology was

later incorporated in a machinemounted, continuous respirable dust

monitor for use in underground mines.

In the early 1980’s, however, it was

determined that this technology was not

effective for monitoring compliance

with the applicable dust standard.

Nevertheless, instruments which used

the light scattering principle were found

to be useful tools to locate dust sources

and to determine its magnitude. Such

instruments continue to be especially

useful for evaluating dust-control

techniques such as dust collectors and

water sprays that can be turned on and

off quickly and repeatedly.

The 1992 Task Group report

recommended the accelerated

development of a fixed-site

underground dust monitor, capable of

providing continuous information on

dust levels and personal sampling

devices capable of providing both shortterm and full-shift exposure

measurements. In response to this

recommendation, the former Bureau of

Mines, with MSHA’s assistance, again

evaluated existing technology that could

be used in the development of a fixedsite underground mine dust monitor.

This was made possible because of

advances in sensing and electronic

signal processing technology that had

occurred since development of the first

generation machine-mounted dust

monitor in the late 1970’s. Eventually a

fixed site/machine-mounted continuous

respirable dust monitor based on the

proprietary mass-measurement

technology known as the tapered

element oscillating microbalance

(TEOM) was developed and field

tested.

The TEOM technique is capable of

continuously weighing a filter upon

which dust is collected. It provides a

real-time record and a permanent record

of the total mass collected on the filter.

The device can display the timeweighted average (TWA) concentration

of respirable coal mine dust (total mass

of dust collected divided by the length

of time the unit was operated), the

instantaneous (real-time) concentration,

and the projected full-shift

concentration. This would allow a mine

operator to adjust control measures or

optimize mining procedures to prevent

miner overexposure. The full-shift

concentration of respirable coal mine

dust would be available at the end of the

shift. The developer of the fixed-site

monitor is also working on a personwearable, end of shift/continuous

respirable dust monitor using the same

TEOM technology.

In addition to the TEOM technology,

NIOSH is developing another personwearable device that has the potential

for continuously monitoring the mine

environment. This device measures the

mass of respirable dust indirectly based

on the amount of pressure drop detected

across the collection filter.

MSHA is seeking ways to encourage

voluntary deployment of this

technology, once it has been verified as

reliable. MSHA has considered allowing

mine operators to adopt a continuous

personal monitoring strategy as part of

the approved ventilation plan, in lieu of

plan verification. Under this approach,

the operator would have the flexibility

of choosing from several technologies

available for continuous personal

monitoring. If an operator adopts

continuous personal monitoring, the

following additional information, at a

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42139

minimum, would be required for the

mine ventilation plan:

1. The specific continuous personal

monitoring device the operator intends

to use which has been approved by the

Secretary;

2. The DO and other occupations or

individuals, including part 90 miners,

that will be sampled on every

production shift and the length of the

production shift to be sampled;

3. The procedures for preventing

exposure above the applicable dust

standard;

4. The manufacturer’s calibration and

maintenance requirements, and a

description of how records of

calibration and maintenance will be

made available to MSHA, miners and

the miner’s representatives; and

5. A description of how end-of shift

measurements will be recorded, who

will certify that such records are

accurate and properly taken, how long

such records will be maintained, where

such records will be made available for

inspection by MSHA, miners and the

miner’s representatives, and how miners

will be notified on each production shift

of the end-of-shift measurements.

At the present time, we do not believe

that technology to enable continuous

monitoring of respirable dust has

advanced to the point where it could be

relied upon as an alternative to plan

verification. In the future, when this

technology is available, MSHA will

consider the implementation of such an

alternative to the proposed plan

verification program. We request

comments on this approach as a

possible alternative to plan verification.

MSHA is specifically interested in any

proposals for the use of continuous

personal monitoring, as well as any

information which may be available

concerning developing technology.

Should an operator be interested in

implementing a continuous personal

monitoring program at a specific mine,

MSHA will review the plan and

consider development of a pilot

program to develop information which

may be useful for future rulemaking.

MSHA is interested in comments

concerning the specific provisions

which should be included in the

ventilation plan to assure that, if an

operator does develop a continuous

monitoring program, miners will not be

overexposed on any individual shift.

IV. Discussion of Proposed Rule

A. Summary

As recommended by the Advisory

Committee in 1996, MSHA is proposing

to assume responsibility for all

compliance sampling for respirable dust

in underground coal mines as required

under CFR parts 70 and 90. This

proposal includes revocation of

bimonthly compliance sampling

requirements, abatement sampling

requirements, the process for

establishing a reduced standard when

quartz is present, and operator sampling

requirements for miners who have

evidence of the development of

pneumoconiosis under part 90. In order

to provide a greater level of protection

than that provided under these

sampling requirements, MSHA is

proposing to require each underground

coal mine operator to have a verified

mine ventilation plan. Under this

proposal, MSHA would verify the

effectiveness of the mine ventilation

plan for each mechanized mining unit

(MMU) in controlling respirable dust

under typical mining conditions.

Mine ventilation plans have long been

recognized as a means of addressing

mine-specific health and safety issues.

Existing § 75.370 requires that each

mine operator design a ventilation plan

to control methane and respirable dust

in the mine. It further requires that the

plan be suitable to the conditions and

mining system at the mine. However,

there is no current provision requiring

the effectiveness of mine ventilation

plans to be verified under typical

mining conditions.

Since 1970, beginning with

enforcement of the Federal Coal Mine

Health and Safety Act of 1969, the level

of respirable dust in underground coal

mines has been significantly reduced.

Although much progress has been made,

MSHA sampling data indicate that some

work environments continue to have

excessive concentrations of respirable

dust. It is MSHA’s position that

excessive dust levels can be

substantially reduced, if not eliminated,

by implementing the Advisory

Committee’s recommendations to

enhance plan quality and strengthen the

plan approval process. Toward this end,

this proposal would revise 30 CFR by

revising part 70, subparts A, B, and C

amending two existing sections of part

75.

This proposal would require evidence

that the mine ventilation plan is

effective in controlling respirable dust

as required by § 75.370. Within the first

30 days of operating a new MMU, or

when required to do so by the District

Manager, mine operators would have to

specify the operating parameters of an

effective plan and then MSHA would

verify the plan’s effectiveness based on

a sufficient number of full-shift samples

taken at designated locations.

Under this proposal, we would collect

full-shift respirable dust samples, called

‘‘verification samples,’’ to demonstrate

the adequacy of the dust control

parameters specified in the mine

ventilation plan in maintaining the

concentration of respirable coal mine

and quartz dust at or below 2.0 mg/m3

and 100 μg/m3, respectively.

For purposes of plan verification,

‘‘full-shift’’ would refer to the entire

work shift during which material is

produced by an MMU. Currently, many

mining operations have work shifts of

more than 8 hours. Miners working

extended shifts should be protected

from the hazards of respirable dust and

quartz by the ventilation plan.

Accordingly, the proposed verification

samples would not be limited to 8 hours

or less, as under the current bimonthly

operator sampling regulations.

A sample would be valid for

verification purposes only if the shift on

which it was taken met certain

requirements. This is necessary in order

to verify that dust controls specified in

the plan are sufficient to prevent

excessive dust concentrations, even

when a higher-than-average amount of

material is produced. The proposed

operator’s requirements for a shift used

for verification sampling are:

(1) The dust controls and work

practices utilized must be those listed in

the mine ventilation plan;

(2) MSHA’s measurements of the

engineering or environmental control

parameters must not exceed 115% of the

quantities specified in the plan; and

(3) The amount of material produced

must be at least the ‘‘verification

production level’’ or VPL.

The VPL is defined as the tenth

highest production level recorded in the

most recent 30 production shifts.

The proposed rule would require

mine operators to: (1) Set and maintain

the dust control parameters during

MSHA verification sampling at levels

specified in the plan; (2) maintain and

make available to MSHA records of the

amount of material produced by each

mechanized mining unit during each

production shift; and (3) provide

additional information in mine

ventilation plans.

The number of samples necessary to

verify that the dust control parameters

proposed for an MMU are effective

would depend on the individual

sample. Since all such measurements

are subject to potential sampling and

analytical errors, some of them may fall

slightly below the verification limit

even when the true concentration of

respirable coal mine dust or quartz does

not. Therefore, to ensure that the

verification limits have actually been

met, it is necessary to provide for a

margin of error in each measurement.

42140 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

The ‘‘critical values’’ established by

MSHA provide this margin of error. If

the VPL is achieved and dust

concentrations are sufficiently low, the

District Manager could approve a plan

based on as few as one shift of sampling.

However, if dust concentration

measurements are higher, or if the

actual production was less than the VPL

MSHA would sample additional shifts.

Consistent with the Mine Act and its

implementing regulations, MSHA’s

longstanding policy has been to

preserve the primacy of engineering

controls, to the extent that they are

technologically and economically

feasible. Consequently, MSHA has not

accepted the use of approved respiratory

protection or administrative controls as

a means of achieving compliance with

the respirable dust standard. In order to

provide all miners with the highest

possible level of health protection, as

intended by the Mine Act, MSHA is

now proposing to permit the use of

approved PAPRs or verifiable

administrative controls to supplement

engineering or environmental controls

under certain circumstances for

compliance purposes. Their use would

be limited to longwall mining

operations and permitted only after

MSHA has determined, upon request of

the operator, that all feasible

engineering or environmental controls

cannot maintain the mine atmosphere

within applicable standards. In such

cases, specific requirements governing

the use of PAPRs or verifiable

administrative controls would be

specified in the mine ventilation plan.

Finally, the proposal would require

you to maintain, and make available to

MSHA inspectors, records of the

amount of material produced by each

MMU during each production shift over

a running six-month period. This, along

with routine bimonthly and other

sampling data, would enable us to

review the suitability of the plan

parameters on an ongoing basis.

Although a VPL would be included in

the ventilation plan, we would not cite

you for producing at levels exceeding

the VPL. We would expect production

on an MMU to exceed the VPL on about

33 percent of all production shifts. If the

District Manager determines that your

production exceeds the VPL on more

than about 33 percent of the production

shifts over a six-month period, then this

may trigger the plan verification process

using a higher VPL.

These and other provisions of the

proposed rule are explained in more

detail in the following section-bysection discussion.

B. Section-by-Section Discussion

This section of the preamble explains,

section-by-section, the provisions of the

proposed rule. The text of the proposed

rule is included at the end of the

document.

Section 70.2 Definitions

The existing definitions of certified

person, concentration, and designated

area (DA) are being modified to more

clearly convey the intended meaning

under the proposal. These modifications

reflect necessary changes as a result of

the removal of existing paragraphs and

the transfer of other paragraphs, as well

as the addition of new references. The

proposal also includes definitions of

new terms to clarify the mine

ventilation plan verification process as

it applies to mechanized mining units

(MMUs). Some of the definitions are for

technical terms developed specifically

for this proposal, such as ‘‘verification

limit’’ and ‘‘verification production

level.’’ Finally, the definitions of

‘‘certified person,’’ ‘‘normal production

shift,’’ and ‘‘valid respirable dust

sample’’ would be removed.

We explain these new and revised

definitions of terms below. You should

also closely examine each proposed

section where the term is used to review

the context in which it is used.

The following existing definitions are

being modified:

Concentration

The existing definition would be

modified so that ‘‘concentration’’ refers

to an 8-hour Mining Research

Establishment (MRE) equivalent

measure of the amount of sampled

material contained per unit volume of

air. The proposed revision would

include the constant factor of 1.38

which the Secretary currently uses to

convert concentration of respirable dust

measured with approved sampling

devices to an equivalent concentration

as measured with an MRE instrument.

MSHA developed the existing coal

mine dust standards from 8-hour shift

exposure measurements. Therefore, if

you take a sample over a period other

than eight hours, you must adjust the

concentration measurement to be

equivalent to an eight-hour exposure.

This will protect miners working shifts

longer than eight hours, and would be

accomplished by multiplying the

sampler flow rate by 480 minutes,

regardless of the length of time during

which the sample was actually

collected. (In these examples, to

determine equivalent concentrations of

respirable coal mine dust: MRE

equivalent concentration (mg/m3)=

accumulated dust (mg)

sampling time (min) * rate of sampling m

 * 3 ( )















 138 .

where: rate of sampling = 0.002 m3/

min).

For example, suppose a DO sample is

collected over a 9-hour shift that

includes one hour of travel time.

Suppose that the amount of dust

accumulated during travel is negligible,

and the amount of dust accumulated

during production is 1.5 mg. If the

concentration were not adjusted to an 8-

hour equivalent, it would be diluted by

the time spent traveling and calculated

as 1.92 mg/m3. Under the proposed

definition, the calculated concentration

would be 2.16 mg/m3.

The proposed definition does not

change the daily limit on accumulated

exposure intended by the existing

exposure limit for coal mine dust. Since

the current limit was based on an

assumption that exposure occurs over

an 8-hour shift, it corresponds to a daily

cumulative exposure limit of 8 × 2.0 =

16 mg-hr/m3. The proposed definition

of concentration would maintain this

same MRE-equivalent 16 mg-hr/m3

daily limit, regardless of the length of

any shift worked.

To continue the example, the

exposure accumulated during a day is

the same, whether from 8 hours at an

average of 2.16 mg/m3 or from 9 hours

at an average of 1.92 mg/m3. In either

case, the MRE-equivalent exposure

accumulated for the day is 17.3 mg-hr/

m3, which exceeds the intended daily

limit of 16 mg-hr/m3. Under the

proposed definition, this would be

reflected by the fact that the calculated

concentration exceeds 2.0 mg/m3.

MSHA solicits comments on this

method of adjusting concentrations to

an 8-hour equivalent.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42141

Designated Area (DA)

The existing definition would be

modified to permit the Secretary to

identify designated areas and to remain

consistent with existing procedures

which have been in effect since 1980.

Once identified, the location of these

DAs and the respirable dust measures to

be used at the dust generating sources

for these locations must be contained in

the operator’s mine ventilation plan as

provided for under § 75.371(t).

However, the operator would not be

required to sample these DA’s under the

proposal. MSHA is also proposing to

transfer the requirement for identifying

each DA specified in existing

§ 70.208(e), which will be removed, to

revised § 70.2(e).

Mechanized Mining Unit (MMU)

The existing definition would be

modified by removing § 70.207(e)

(Bimonthly sampling; mechanized

mining units) which will be deleted,

and revising § 70.207; and by

transferring the requirements for

identifying each MMU specified in

existing §§ 70.207(f)(1) and (f)(2), to

revised § 70.2(o).

Quartz

The existing definition of quartz

would be modified by specifying the

analytical method that MSHA has been

using since 1983 to determine the quartz

content of respirable dust samples. The

reason for this modification is to

standardize the procedure, thereby

enabling other laboratories to reproduce

quartz determinations made by MSHA.

The following new definitions are

being proposed:

Critical Value

‘‘Critical value’’ would mean the

maximum acceptable full shift dust

concentration measurement

demonstrating that the applicable

verification limit has been met at a high

level of confidence. Appendix A

explains how each critical value was

derived. The specific critical values and

their use are detailed in §§ 70.209 and

70.213.

Dust Control Parameters

‘‘Dust control parameters’’ would

mean the respirable dust control

requirements of a mine ventilation plan,

including engineering or environmental

controls, maintenance procedures, and

any other requirements described in a

ventilation plan. These requirements are

intended for the protection of miners

from excessive levels of respirable dust

and must be in place on every

production shift. To assure compliance

with the ventilation plan, you must

check the dust control parameters on

each MMU before beginning production,

as required under § 75.362(a)(2). This

term has not been formally defined until

now.

Engineering or Environmental Controls

‘‘Engineering or environmental

controls’’ would mean all methods that

control the level of respirable dust in

the work environment by either

reducing dust generation or by

suppressing, diluting, capturing or

diverting the dust being generated

during the mining process. Throughout

the proposal, the terms ‘‘engineering’’

and ‘‘environmental’’ controls are used

interchangeably. The Racal Airstream

helmet (or the 3MTM AirstreamTM

Helmet-Mounted PAPR), or any other

respiratory protective device approved

and labeled as such by the National

Institute for Occupational Safety and

Health (NIOSH), is not defined as an

engineering or environmental control.

Full Shift

‘‘Full shift’’ is defined differently for

purposes of plan verification and

abatement sampling, and for bimonthly

compliance determinations. For

purposes of abatement and plan

verification, ‘‘full shift’’ would mean an

entire work shift, including travel time

to and from the MMU. Because of the

way MSHA intends to define

‘‘concentration,’’ this would be equally

protective regardless of the production

and travel times. For example, suppose

miners at one MMU travel for one hour

and mine for eight hours. Miners at

another travel for two hours and also

mine for eight hours. Suppose, further,

that the dust concentration during travel

is negligible and that the dust

concentrations are identical during

production at the two MMUs. Then the

amount of dust accumulated on a filter

will be the same, say 1.0 mg, in both

cases. Applying the proposed definition,

the dust concentration calculated for

both MMUs would be 1.44 mg/m3.

For purposes of bimonthly

compliance determination, MSHA

would continue its current practice of

limiting sampling to a 480-minute

maximum. MSHA solicits comments on

whether ‘‘full shift’’ for compliance

sampling purposes should be defined in

the same way as for abatement and plan

verification purposes. MSHA also

solicits comments on whether ‘‘full

shift’’ should be defined, as proposed,

in the same way for abatement and plan

verification purposes.

Material Produced

‘‘Material produced’’ would mean the

total amount of coal and/or other

substance extracted by an MMU during

any production shift. In order to

properly assess the effectiveness of the

mine ventilation plan requirements for

respirable dust control and for

subsequent monitoring purposes, MSHA

proposes to require that the operator

record and make available records of the

amount of material produced by each

MMU each shift under a new paragraph

(h) of § 75.370.

MRE

‘‘MRE’’ would mean Mining Research

Establishment of the National Coal

Board, London, England.

Powered Air-Purifying Respirators

(PAPRs)

‘‘Powered, air-purifying respirators

(PAPR)’’ would mean a NIOSH

approved loose-fitting respirator that

uses a blower to force the ambient air

through air-purifying elements to

deliver filtered air to the miner’s

breathing area. Under the proposal, an

operator who employs longwall mining

has the option of using either powered,

air-purifying respirators (PAPRs) or

verifiable administrative controls as a

supplemental means of control once

MSHA has determined that

concentrations of respirable dust have

been reduced as low as is feasible with

engineering and environmental controls.

This may include RACAL Airstream

helmets or similar devices that are

available now or in the future. The

reason for excluding other types of

approved respirators is discussed in

section II.B.1.

Verifiable Administrative Control

‘‘Verifiable administrative control’’

would mean a work practice intended to

reduce the miner’s full shift exposure to

respirable dust hazards by altering the

way in which work is performed.

Examples include rotation of miners to

areas having lower concentrations of

respirable dust, rescheduling of tasks,

and modifying work activities to reduce

exposure. A ‘‘verifiable administrative

control’’ must be (1) capable of review

to confirm proper implementation; (2)

clearly understood by miners; and (3)

applied consistently over time.

Verification Limits

‘‘Verification limits’’ would mean the

maximum dust concentration for which

the ventilation plan has been verified as

effective in maintaining during the full

shift. There are two separate verification

limits: An MRE-equivalent

concentration of 2.0 mg/m3 for

respirable coal mine dust and an MREequivalent concentration of 100 μg/m3

for respirable quartz dust. Both of these

42142 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

limits apply to dust concentrations

measured over a full shift.

MSHA does not enforce a separate

standard for quartz dust. It regulates

exposures to quartz and coal mine dust

by reducing the applicable standard for

coal mine dust, by means of a formula,

when quartz content of the respirable

dust is above 5 percent. This formula

(10 divided by the concentration of

quartz, expressed as a percentage)

establishes an applicable coal mine dust

standard that, in effect, limits quartz

concentrations in the mine environment

to no more than 100 μg/m3. For

example, when the quartz content is 5

percent, the applicable standard is 2.0

mg/m3; when the quartz content is 10

percent, the applicable standard is 1.0

mg/m3. Five percent of 2.0 mg/m3 and

10 percent of 1.0 mg/m3 are each 0.100

mg/m3 or 100 μg/m3.

The Advisory Committee recognized

that a significant quartz exposure hazard

continues to exist in coal mines,

especially for operations such as roof

bolting. Based on MSHA data, 66

percent of underground coal mines are

operating on a reduced dust standard

due to the respirable dust in the mine

environment containing a high

percentage of quartz. MSHA data also

indicates that 73 percent of the over 600

roof bolters and over 29 percent of the

MMUs sampled bimonthly by mine

operators are operating under reduced

dust standards. The number of reduced

standards in effect indicates that a

significant potential health risk due to

quartz exposure continues to exist.

Under the current program, miners can

be exposed to excessive quartz levels

while the dust standard-setting process

takes place. For example, consider a

recent situation where an MSHA dust

sample of a roof bolter was 0.9 mg/m3;

a level that was in compliance with the

applicable standard, 1.3 mg/m3.

However, when the sample was

analyzed for quartz the results indicated

that the actual concentration of quartz

dust in the mine environment exceeded

270 μg/m3; or more than two and a half

times above the permissible level of 100

μg/m3. The only action that could be

taken in this particular situation was to

initiate the dust standard-setting

process, which, on average, can take at

least one month or longer. The existing

standard-setting process continues from

the time the operator is cited for

violating the reduced standard through

the time MSHA enforces final corrective

action.

Under this proposal, MSHA would

require operators to anticipate the

potential for quartz exposure and to

incorporate controls prior to approval of

the mine ventilation plan. In order to

verify that the operator has incorporated

such controls, MSHA would determine

the mass of quartz contained in each

verification sample and express the

concentration of quartz in the mine air

as an airborne concentration and not as

percent quartz in the dust during the

verification process.

This process would require operators

to address both the potential for

respirable coal mine dust and quartz

dust exposure. As recommended by the

Advisory Committee, the proposed plan

verification process would establish a

monitoring and compliance framework

to aid MSHA and the coal mine operator

in targeting mining situations where

quartz exposure constitutes a significant

hazard and enhanced dust control

procedures are required.

Verification Production Level (VPL)

The ‘‘VPL’’ would mean the tenth

highest production level recorded in the

most recent 30 production shifts. It is an

estimate of the 67th production

percentile within an MMU. (§ 70.208

explains how to establish the VPL if you

do not have records for 30 production

shifts.)

We believe that the production

criteria used to evaluate plan

effectiveness may not adequately

represent typical conditions under

which miners work. Requiring that

plans be verified at or above this VPL

would provide assurance that excessive

dust concentrations would be avoided

on a majority of production shifts.

MSHA believes that using this VPL is

more protective of miners’ health than

the current practice of evaluating plan

adequacy based on MSHA inspector

samples taken when production can be

as low as 60 percent of the average

production. We note however, that a

VPL defined as a higher production

percentile than is being proposed would

likely assure that miners would be more

protected on a majority of production

shifts. The Agency welcomes comments

on both the use of a VPL and the

appropriate production percentile to use

to define it.

Since approximately 50 percent of all

production shifts are expected to exceed

average production, it follows that the

vast majority of all production shifts

exceed 60 percent of average

production. Therefore, by using 60

percent of average production as the

lower range of the production criteria

for plan evaluation purposes, as

required under current inspection

procedures, we have no assurance that

the plan would be effective under the

vast majority of production conditions.

If you do not have records for 30

production shifts, you can use the

minimum production actually achieved

on a shift used to verify the plan’s

effectiveness as your VPL.

Verification Sample

‘‘Verification sample’’ would mean a

sample collected for purposes of plan

verification. In order to be valid the

sample must be collected on a full shift

during which the amount of material

produced is at or above the VPL. Only

those engineering or environmental

controls and other measures listed in

the mine ventilation plan may be

employed, at levels not exceeding 115%

of the quantities specified in the plan

during the shift in which the sample is

collected. For example, if the plan

specifies an air quantity of 4,000 cfm,

the quantity measured during

verification must not exceed 4,600 cfm

(4,000 cfm x 1.15 = 4,600).

Section 70.100 What are the respirable

dust standards when quartz is not

present?

MSHA is proposing no substantive

changes to existing § 70.100(a) and (b),

except for removing the reference to

§ 70.206 (Approved sampling devices;

equivalent concentrations) from existing

paragraphs (a) and (b) and replacing it

with revised § 70.2(c). The requirements

of revised § 70.2(c) are similar to the

previous standard in § 70.206. The

proposal retains the respirable dust

standard of 2.0 mg/m3 in existing

paragraph (a) and the intake air standard

for respirable dust of 1.0 mg/m3 in

existing paragraph (b).

Section 70.101 What is the respirable

dust standard when quartz is present?

MSHA is proposing to retain the

existing formula (10 divided by the

concentration of quartz, expressed as a

percentage) for reducing the respirable

dust standard below 2.0 mg/m3 when

the quartz content of the respirable dust

in the mine atmosphere is above 5

percent. However, the Agency is

proposing to change how it arrives at an

average quartz percentage that is used to

establish an applicable dust standard.

MSHA recently published a proposed

‘‘Program Policy Letter (PPL) on

Samples Used to Determine the

Respirable Dust Level When Quartz is

Present’’ for public comment [64 FR

65671, November 23, 1999] whereby the

standard would be determined based

solely on the results of multiple MSHA

samples. Under this proposal, as in the

PPL, MSHA would no longer be using

a combination of MSHA and mine

operator sampling for determining the

average quartz percentage, which has

been the practice since 1985. Instead, as

discussed in section III.B, this proposal

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42143

would establish MSHA sampling as the

exclusive basis for determining the

reduced standard and require three

valid MSHA samples to set a reduced

standard. Since we are sampling

underground mines bimonthly, we will

have no difficulty in collecting the

required number of samples to arrive at

the average quartz percentage. We

believe our samples will be more

representative of the level of quartz to

which miners are exposed than as

determined currently. This increased

level of sampling should also allay any

operator concerns regarding the

collection of ‘‘misleadingly high’’

samples during atypical periods. We

would also begin reporting quartz levels

to the nearest tenth of a percent. This is

intended to be more protective for the

miner than under the current program of

truncating results to the nearest full

percent. We believe that the method for

establishing reduced standards will be

more protective for the miners than the

current program.

Verification of Ventilation Plan

Effectiveness.

Existing § 75.370 requires you to

develop an underground coal mine

ventilation plan that is designed to

control methane and respirable dust in

the mine. It further requires that the

plan be suitable to the conditions and

mining systems at the mine. Proposed

§§ 70.201 to 70.211 sets forth the steps

that MSHA will follow to demonstrate

that your mine ventilation plan required

by § 75.370 is effective in controlling

respirable dust under typical mining

conditions. This demonstration would

be required before MSHA approves the

mine ventilation plan.

Under §§ 70.201 to 70.211, MSHA

would verify the effectiveness, for the

control of respirable dust, of all mine

ventilation plans submitted to the

District Manager for approval under

§ 75.370. To do this, MSHA would

collect full shift samples, called

‘‘verification samples.’’ For MSHA to

approve the plan, these samples would

have to demonstrate that the plan’s dust

control parameters are effective in

maintaining concentrations of respirable

coal mine dust and quartz dust in the

working environment of MMUs at or

below 2.0 mg/m3 and 100 μg/m3,

respectively, under typical mining

conditions.

MSHA has drafted the regulatory text

of this proposal in a question and

answer format. The remainder of the

Section-by-Section discussion also

follows this format. As discussed in

Chapter IV paragraph A below, we

request your comments on this format.

Section 70.201 Who must have a

verified ventilation plan?

Section 75.370 requires all

underground coal mine operators to

submit a mine ventilation plan for

approval. The proposed § 70.201 would

require the verification of these plans in

terms of their effectiveness in

controlling dust.

Section 70.202 What is a verified

ventilation plan?

A ventilation plan submitted under

§ 75.370 must be designed to control

respirable dust and must be suitable to

the conditions and mining systems at

the mine. In order for the plan to be

verified under this proposal, the plan’s

dust control parameters must be

demonstrated to be effective, at a high

level of confidence, in maintaining the

concentration of respirable coal mine

dust and quartz dust in each MMU at or

below 2.0 mg/m3 and 100 μg/m3,

respectively. This demonstration would

be based on MSHA full shift verification

samples, which are collected when the

amount of material produced is at or

above the VPL and only the engineering

or environmental controls and other

measures included in the ventilation

plan are in place, at levels not exceeding

115% of the quantities specified in the

plan.

Section 70.203 What will trigger the

plan verification process?

There are several ways in which the

plan verification process could be

initiated. You would trigger the process

by submitting a new ventilation plan

under § 75.370, or amending a

previously approved ventilation plan

under § 75.371(f). The verification

process could also be triggered if the

District Manager requires you to change

your plan after determining that your

dust control parameters are no longer

effective. Finally the verification

process could be triggered if you

propose revisions to a previously

verified ventilation plan and the District

Manager determines that the proposed

revisions may cause the plan to be

inadequate.

Once your ventilation plan has been

verified as effective, it should not be

necessary to reverify your plan every six

months. However, you may be required

to change your plan parameters based

on (1) results of the MSHA six-month

review of the ventilation plan as

required by § 75.370(g), (2) excessive

dust concentrations measured by MSHA

sampling, or (3) a new reduced

applicable dust standard which is less

than the highest respirable coal mine

dust concentration that was previously

used to verify the plan. For example, if

you are cited by MSHA for exceeding

the applicable dust standard the District

Manager may have cause to question the

adequacy of the previously-approved

plan.

Also, depending on sampling results

and production records, if your

production exceeds the VPL during

MSHA sampling, the District Manager

may require you to verify the ventilation

plan at the higher production level. For

example, suppose your VPL is 10,000

tons and all five MSHA concentration

measurements exceed the applicable

standard on a shift for which the

production is 12,000 tons. Then, if your

production records indicate that you

have exceeded the VPL on more than 33

percent of all production shifts during

the previous six months, MSHA would

initiate the verification process.

Section 70.204 When will MSHA

conduct verification sampling?

The District Manager will notify you

of the schedule for verification sampling

after granting provisional approval of

your ventilation plan. However, before

you receive provisional approval, you

may be required to change your plan if

the District Manager determines that

your dust control parameters are

inadequate or unsuitable for the current

mining conditions. If provisional

approval is not granted, you may not

operate the affected MMUs. Since more

than 700 existing mine ventilation plans

may require verification, MSHA will not

be able to verify all plans immediately.

Under proposed § 70.204 the District

Manager would notify you of the date

when MSHA intends to collect

verification samples.

Section 70.205 What must I (the

operator) do to comply this standard?

When the District Manager notifies

you that your mine has been scheduled

for verification sampling, you would

need to make sure that all the dust

control parameters specified in your

ventilation plan are fully implemented.

Since the objective of plan verification

is to determine the effectiveness of the

plan’s dust control parameters in

controlling respirable dust under typical

mining conditions, paragraph (a) would

require you to utilize only the dust

control parameters listed in the

ventilation plan that was provisionally

approved by the District Manager. On

the date scheduled for verification

sampling, you should establish

production levels at or above the VPL

specified in the plan, using only the

dust control parameters and other

measures listed in the plan.

42144 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

8Assuming no special production effort, the

probability of needing more than n shifts to be

sampled before you met the minimum production

level required to verify the plan: P(X>n)= (.667) n;

for example, the probability of more than 10 shifts

being needed, P(X>10) = (.667) 10 = 1.7 percent.

9Assuming no special production effort, the

probability of needing n or fewer shifts to be

sampled before you met the minimum production

level required to verify a plan: P(X≤n)=1¥P(X≥n);

for example, the probability of 10 or fewer shifts

being needed, (1¥(.667) 10) = 98 percent.

Recognizing that engineering or

environmental controls such as air

quantity and velocity are subject to

measurement error and cannot easily be

controlled with absolute precision,

MSHA would allow the measured levels

to be up to 115% of the levels specified

in the plan. If, on the date of verification

sampling, a measured quantity exceeds

the corresponding quantity specified in

the plan by more than 15 percent, you

will have the option to either (1) adjust

the parameter(s) to what is specified in

the plan before verification sampling

begins or (2) make no adjustment to the

parameter(s) prior to verification

sampling. Under the second option,

plan approval will be contingent on

incorporating into your plan the

maximum values of parameters in effect

during verification sampling. If

verification samples were taken when a

parameter measurement exceeded 115

percent of the level specified in the

plan, then (assuming none of the

verification samples exceeded the

critical values) that parameter quantity,

as measured, would be incorporated in

the plan ultimately approved by the

District Manager.

As of the effective date of the final

rule, you would be required to begin

maintaining records of the amount of

material produced by each MMU during

each shift. This would enable you to

establish the ‘‘verification production

level’’ (VPL)—the minimum production

level at which you must demonstrate

the plan’s effectiveness.

Before you submit a previously

approved ventilation plan to the District

Manager for review and approval,

proposed paragraph (c) would require

you to provide additional information.

This additional information is described

under § 75.371(f) of this proposal.

To enable us to maximize our

inspection resources and to promote an

orderly verification process, proposed

paragraph (d) would require you to

notify the District Manager in a timely

manner if you are unable to meet the

conditions for verification sampling on

the scheduled date. Failure to provide

notification may be cause for revocation

of the provisional approval of your

ventilation plan.

In accordance with section 103(f) of

the Mine Act and the recommendations

of the Advisory Committee, miners and

their representatives would be provided

the same walkaround rights during plan

verification sampling as they are

provided during any other physical

inspection made pursuant to the

provisions of section 103(a) by an

authorized representative of MSHA.

MSHA believes that under the

guidance of the Interpretive Bulletin (43

FR 17546, April 25, 1978) these rights

arise when: (1) An ‘‘inspection’’ is made

for the purposes set forth in section

103(a), and (2) the inspector is

physically present at the mine to

observe or monitor safety and health

conditions as part of direct safety and

health enforcement activity.

The process of plan verification

sampling is necessary to obtain

information related to approval of the

mine’s ventilation plan and whether

coal mine dust will be adequately

controlled to protect miners health.

Consequently, miners and their

representative would have the right to

accompany the inspector with no loss of

pay for the time during which the

representative exercises this right.

However, this right is limited by Section

103(f) to only one such representative of

miners.

Section 70.206 Who will MSHA

sample and where will MSHA place the

sampling device(s) when conducting

verification sampling?

MSHA will sample specific

occupations within an MMU to

demonstrate your plan’s adequacy.

These occupations would be selected

because, based on past experience,

within an MMU they would likely be

exposed to the highest respirable coal

mine dust concentration and, therefore,

would be at greatest risk of

overexposure. Therefore, MSHA would

sample the environment of the DO (as

under existing § 70.207), the roof bolter

operator(s) (occupation codes—012, 014

or 046), the longwall jack setters

(occupation code—041), and any other

occupation that the District Manager

may designate for sampling after

reviewing your ventilation plan.

Section 70.207 How many shifts will

MSHA sample to verify my ventilation

plan?

This proposed section would explain

that the number of shifts required to

verify your ventilation plan would

depend on two factors: first, the actual

operating conditions during the shift

that is sampled; and, second, the sample

results. To qualify as a verification

sample, the amount of material

produced by the MMU must equal or

exceed the VPL, and the dust control

parameters must be at levels not

exceeding 115 percent of the quantities

specified in the plan. Therefore, the

number of shifts depends largely on

how quickly and consistently you are

able to achieve these operating

conditions. We may need to sample

several production shifts before the

production level on any single shift

qualifies for verification purposes. We

may verify the plan based on this single

shift—but only if all concentration

measurements on the sampled shift are

at or below the appropriate critical

values proposed in § 70.209. This would

demonstrate the plan’s effectiveness at a

high level of confidence. If any of the

measurements exceed the appropriate

critical value, then we would collect

verification samples taken on one to

three additional shifts, depending on

the concentrations measured on those

shifts. Since these additional shifts must

also meet the criteria for production,

and use only the engineering or

environmental controls and other

measures specified in the ventilation

plan, we may have to sample a total of

more than four shifts.

Assuming that you make no special

effort to meet the VPL during

verification sampling, there is a 67-

percent probability that a randomly

selected production shift would not

meet the VPL. Consequently, if you

made no special production effort, there

would be a 13-percent chance we would

need to sample more than five shifts and

a 1.7-percent chance we would have to

sample more than 10 shifts. 8 On the

other hand, again assuming no special

production effort, there would be a 98-

percent chance we would need 10 or

fewer shifts and a 70-percent chance

that we would need three or fewer

shifts. 9 This assumes that the dust

concentration measurement for each

shift does not exceed the critical value

corresponding to the number of shifts

sampled. If you make a special effort to

achieve high production on the sampled

shifts, then fewer shifts would be

required.

Section 70.208 What if 30 shifts of

production data are not to establish the

verification production level (VPL)?

If you are starting a new MMU or

mine, you may not have 30 shifts of

production data available when you

submit a new ventilation plan. In such

cases, proposed § 70.208 requires you to

establish the VPL as the minimum

production level actually achieved on a

shift used to verify the plan’s

effectiveness. For example, assume we

initiate verification sampling of your

longwall MMU. Based on the dust

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42145

concentration measurements obtained

on the first shift sampled, your MMU

happens to exceed either 1.85 mg/m3 for

respirable coal mine dust or 93 μg/m3

for quartz dust but not the verification

limits. According to the applicable

critical values table in § 70.209, we

would need to sample at least two more

shifts to verify your plan’s effectiveness,

provided that no sample exceed 1.93

mg/m3 for respirable coal mine dust or

97 μg/m3 for quartz dust. Assume that

the highest production level was

achieved on the third shift sampled and

the dust concentration measurements

obtained on that shift were low enough,

according to the applicable critical

values table in § 70.209, to verify plan

effectiveness based on a single shift. In

this case, you would establish a VPL

equal to the production achieved on that

shift. If, on the other hand, the dust

concentration measurements obtained

on the third shift with the highest

production level were not low enough

to verify the plan on a single shift and

a determination of the plan’s adequacy

was based on these three shifts, your

VPL would be the minimum production

achieved during verification sampling.

In any case, the VPL would become part

of your ventilation plan.

Section 70.209 When will MSHA

approve my ventilation plan?

This is a new section that proposes

‘‘critical values’’ that the District

Manager would use to determine

whether your plan’s dust control

provisions should be approved. These

critical values, which differ according to

the number of shifts used for

verification, are listed in Table IV–1.

When verification sample results do not

exceed the appropriate critical value for

respirable coal mine dust or quartz dust,

we can be confident that the engineering

or environmental controls in place

during verification sampling

successfully prevented excessive dust

concentrations at the sampled locations.

Therefore, MSHA would approve your

plan when the dust control parameters

are in place during verification

sampling and none of the measurements

obtained from your verification samples

exceeded the appropriate critical value.

Appendix A explains how the critical

values were derived.

TABLE IV–1.—CRITICAL VALUES FOR VERIFYING PLAN EFFECTIVENESS. THE RESULT OF EACH VERIFICATION SAMPLE

COLLECTED MUST BE LESS THAN OR EQUAL TO THE APPROPRIATE CRITICAL VALUE

Number of shifts meeting criteria for verification sampling

Critical value

for coal mine

dust

(mg/m3)

Critical

value for

quartz dust

(μg/m3)

1 ..................................................................................................................................................................................... 1.71 87

2 ..................................................................................................................................................................................... 1.85 93

3 ..................................................................................................................................................................................... 1.93 97

4 or more ....................................................................................................................................................................... 2.0 100

The proposed approval process would

allow the District Manager to base

verification sampling on a reasonably

small number of shifts, while

maintaining a high level of confidence

that approved ventilation plans

adequately prevent excessive dust

concentrations. We would have to

sample at least one full shift under the

operating conditions specified in the

mine ventilation plan before we could

make any determination of the plan’s

adequacy. The plan would be approved

if all samples on that shift meet the

criteria for a verification sample as

defined in § 70.2, and none of the

sample results exceed the appropriate

critical value for a single shift listed in

Table IV–1. However, if any verification

sample resulted in a coal mine dust

measurement greater than 1.71 mg/m3

or a quartz dust measurement greater

than 87 μg/m3, samples would be taken

on additional shifts.

The following two examples illustrate

how we would determine if your plan’s

dust control provisions should be

approved:

Example 1: Suppose samples were taken

on two shifts. We would approve the dust

control provisions of your plan if all quartz

and coal mine dust measurements obtained

on the two shifts were less than 1.85 mg/m3

or 93 μg/m3, respectively. On the other hand,

if one of the roof bolter samples resulted in

a quartz concentration measurement of 95 μg/

m3, then we would not approve your plan,

based on these two shifts alone. Instead, at

least one additional shift would be needed.

Verification samples from only one

additional shift would be sufficient if none

of the coal mine dust measurements on that

shift exceeded 1.93 mg/m3, and none of the

quartz measurements exceeded 97 μg/m3.

(Dust control parameters and production on

this additional shift, as well as on the first

two shifts, would need to meet the criteria for

verification samples in proposed § 70.2 (bb).)

Example 2: Suppose verification samples

were taken on four or more shifts. We would

approve the dust control provisions as

proposed if no measurement exceeded 2.0

mg/m3 of coal mine dust or 100 μg/m3 of

quartz dust.

Section 70.210 What must I (the

operator) do if one or more verification

samples exceed either verification limit?

This is a new section that would

require you to take certain actions

whenever a verification sample results

in a measurement exceeding the

verification limit for either respirable

coal mine dust (2.0 mg/m3) or quartz

dust (100 μg/m3). You would be

required to immediately identify the

cause of the high dust concentration and

prevent miners from being overexposed

on subsequent shifts.

When you receive notice from MSHA

that you have exceeded either

verification limit, you must immediately

take corrective action. You must lower

excessive respirable dust

concentrations, so that none of your full

shift measurements exceed verification

limits in any of the identified

occupational environments or sampling

locations. At the same time, you must

make approved respiratory equipment

available to affected miners in

accordance with § 70.300.

You would also be required to

document the corrective actions taken

for the District Manager, within five

days of MSHA’s notification that you

have exceeded a verification limit. This

documentation must describe all of your

corrective actions, including proposed

changes in dust control parameters. You

would be encouraged to seek technical

assistance from the District Manager to

help you determine what additional

corrective measures would be

reasonably likely to reduce excessive

dust concentrations.

The District Manager will notify you

if your ventilation plan is provisionally

approved and when MSHA will again

commence verification sampling. The

District Manager may require you to

make additional changes in your plan

parameter(s) based on the results of

verification sampling before starting

sampling over again. If no changes are

required, MSHA will continue

42146 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

verification sampling from the point at

which it stopped.

The District Manager would choose,

on a case-by-case basis, between

resuming verification sampling or

starting plan verification anew. MSHA

would not necessarily require a revision

of the ventilation plan nor start the

ventilation verification process over

again because a verification sample

exceeded the verification limit by a

small amount, such as 0.05 mg/m3. The

decision to continue with your current

ventilation plan or start over again with

a new ventilation plan, would be based

on the information you provide

regarding the cause of any excessive

dust concentration measurements and

the steps you have taken to prevent

similar occurrences in the future. For

example, suppose dust concentration

measurements are excessive due to a

deviation in your established operating

procedures. It should be possible for

you to prevent such occurrences in the

future without changing the ventilation

plan. If the District Manager finds this

to be the case, and accepts your

proposed action to prevent similar

occurrences, MSHA would resume

verification sampling. However, the

District Manager may determine that the

ventilation plan is not adequate for

current operating conditions and require

you to change the plan parameters. If so,

MSHA would start the verification

sampling process over again.

MSHA would not issue citations for

exceeding verification limits during the

plan verification process. However,

MSHA will issue citations under

proposed § 70.210(a) for failure to take

action required to address the cause of

the excessive dust levels once you have

been notified by MSHA.

Section 70.211 What if verification

samples continue to exceed either

verification limit even though I (the

operator) believe all feasible engineering

and environmental controls are in

place?

This proposed section would

continue to require you to use all

feasible engineering or environmental

controls before implementing any

supplemental means of control at

longwall mining operations. For

continuous and conventional mining

operations MSHA would suggest

additional engineering and

environmental controls. Even if these

controls do not prevent full shift

respirable dust concentrations from

exceeding the verification limits, you

must continue to use them to reduce

respirable dust to the lowest feasible

level. Engineering or environmental

controls have been the primary form of

dust control for the past 30 years. The

Advisory Committee recommended that

engineering or environmental controls

remain the primary means of protecting

coal miners. Consistent with the Mine

Act and the Advisory Committee’s

recommendation, under this proposal

engineering or environmental controls

continue to be recognized the primary

means to control exposure to respirable

dust.

If you operate an MMU employing

either a continuous or conventional

mining method, we believe feasible

engineering or environmental controls

are available to control respirable dust

to an acceptable level. Controls include

better design of water spray systems for

dust suppression and air movement, use

of dust collectors, and improved face

ventilation systems.

Of approximately 800 continuous

miner MMUs operating in over 500

underground mines, over 90 percent

employ extended cut techniques and are

being operated remotely (Elam, August

1999). As a result, the continuous miner

operator, the occupation normally

identified as the DO for bimonthly

sampling purposes, is no longer

required to work close to the face area

where material is being extracted.

Roof bolting machines, a major

generator of respirable quartz dust on

continuous miner MMUs, must be

equipped with suitable drill dust

controls. Under § 72.630, drill dust must

be controlled by permissible dust

collectors, by water, water with a

wetting agent, by ventilation, or by any

other method approved by MSHA.

These and other approaches, as well

as results of laboratory and field studies

of the effectiveness of various dust

controls, can be found in several

detailed compilations prepared by the

former U.S. Bureau of Mines, whose

responsibilities have now been

transferred to NIOSH. (U.S. Bureau of

Mines various reports, undated). If you

exceed either verification limit, the

District Manager will suggest that you

implement additional controls.

As discussed in section II. B., MSHA

recognizes that improvements in control

technology have not kept pace with the

increase in production technology

associated with high-production

longwall MMUs. Average longwall shift

production reported during bimonthly

sampling has increased from 890 tons

per shift in 1980, to over 4900 tons per

shift in 1999. Given the state of longwall

dust control technology, the currentlyavailable engineering or environmental

controls may not succeed in sustaining

continuous compliance at certain

locations downwind of the longwall

operator (occupation code—044) at

some high-production longwall MMUs

under typical mining conditions.

For your longwall operation, if you

believe that you have implemented all

feasible engineering or environmental

controls, you may submit a written

request to MSHA’s Administrator for

Coal Mine Safety and Health in

Arlington, Virginia, to request for

MSHA to review your longwall mining

operation and determine if you have, in

fact, implemented all feasible

engineering controls.

Upon receipt of such a request, MSHA

would solicit guidance from a panel of

experts which would be established for

making such determinations. Members

of this panel would have extensive

knowledge in respirable dust control

and would represent the following

organizations within MSHA: Technical

Support, Division of Health, the MSHA

District having jurisdiction over your

mine, and one other MSHA District. In

some cases, we may solicit advice from

NIOSH. As part of their deliberations,

the expert panel may visit your mine to

observe the various controls in

operation. Any decisions reached by

this panel would be based on the review

of available information, their combined

experience in dust control, and sound

engineering judgement.

If the Administrator determines that

you are using all feasible engineering or

environmental controls, we would

notify you in writing that you have been

granted approval to use either PAPRs

approved under 42 CFR 84 or verifiable

administrative controls as a

supplemental means of control to

protect miners required to work

downwind of the longwall operator.

You would also be informed that the

location of the DO would be changed

from the 060 to the 044 occupation, or

other occupation designated by the

District Manager depending on how

your longwall MMU is ventilated. You

must continue to maintain the work

environment of the new DO at or below

the verification limits using engineering

or environmental controls, as

demonstrated during plan verification.

As discussed earlier, while it may be

difficult to make the environment safe

for some miners working on the

longwall face under certain mining

conditions, MSHA believes that an

acceptable work environment can be

provided for the longwall operator

(occupation code—044) and other

miners on a continuing basis. You must

choose either PAPRs or verifiable

administrative controls for your

ventilation plan. The notification would

grant approval of an interim verification

plan allowing the use of PAPRs or

administrative controls as a

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42147

supplemental means of compliance.

You must introduce additional

engineering or environmental controls

as they become available and feasible.

Every six months, as part of our regular

review of your mine ventilation plan,

we would follow-up on your efforts to

comply with this requirement.

Sections 70.212 through 70.215

Use of Approved Powered, Air Purifying

Respirators

These sections would establish the

requirements for utilizing PAPRs to

supplement engineering or

environmental controls.

Section 70.212 For my longwall

operation, what must I (the operator) do

in order to use approved PAPRs to

supplement engineering or

environmental controls?

This proposed section would require

you to submit a revised ventilation plan

to MSHA within five days of receipt of

MSHA’s written approval in accordance

with § 70.211 if you choose to use

approved PAPRs to supplement

engineering or environmental controls.

Your revised plan must specify the

engineering or environmental controls

you believe are capable of maintaining

respirable dust concentrations (1) at or

below the verification limits in the

environment of the new DO (previously

occupation 060, and currently

occupation 044 or another occupation

designated by the District Manager), and

(2) at or below two times the verification

limits in the environment of any miner

working on the longwall face

(downwind of the DO) who is required

to wear a PAPR.

This is based upon the demonstrated

effectiveness of PAPRs on longwall

MMUs and the range of longwall air

velocities observed by MSHA inspectors

discussed earlier in section II.B.2, which

led MSHA to reduce the protection

factor assigned to loose fitting, helmeted

PAPRs from 25 to two. In other words,

the maximum full shift, MRE-equivalent

concentration of respirable dust allowed

in the environment of any miner

working on the longwall face

(downwind of the DO) who is required

to wear a PAPR cannot exceed 4.0 mg/

m3 of respirable coal mine dust and 200

μg/m3 of respirable quartz dust.

In addition to specifying all feasible

engineering or environmental controls

to be used, you would be required to

include in your plan a written

respiratory protection program for

PAPRs for all affected miners as

described in § 72.710. MSHA’s District

Manager may require you to modify the

respiratory protection program before

granting provisional approval of your

ventilation plan.

Once MSHA grants provisional

approval, we will verify the

effectiveness of the revised dust control

provisions of the ventilation plan. We

will sample the environment of the DO

and of those miners that your plan

requires to wear approved PAPRs. If

effectiveness of the plan is verified, it

would become your interim ventilation

plan.

In order to continue using PAPRs for

compliance purposes, you would be

required to maintain the effectiveness of

your engineering or environmental

controls, as well as the effectiveness of

your approved PAPR respiratory

protection program. We believe that the

effectiveness of a PAPR is dependent

upon proper training and continued

maintenance. Training and maintenance

procedures are part of an effective

respiratory protection program. The

provision 30 CFR 72.710 requires all

respirators used in an underground coal

mine to be selected, fitted, used, and

maintained in accordance with the

provisions of the American National

Standards Institutes ‘‘Practices for

Respirator Protection ANSI Z88.2–

1969.’’ These provisions include

training miners in the use and

maintenance of respirators and the

limitations of the specific respirator

worn. Necessary maintenance includes

examining it for defects prior to use,

charging the batteries properly, and

appropriate replacement of parts

including, but not limited to, the filter

elements, visors, batteries, blowers, and

face seals. Furthermore, all respiratory

equipment used in an underground coal

mine must be approved by the National

Institutes for Occupational Safety and

Health (NIOSH) under 42 CFR part 84.

The use of PAPRs is not intended to

be permanent. Their use as a

supplemental control would be

permitted only on an interim basis, until

feasible engineering or environmental

controls become available. You would

have to implement any feasible

engineering and environmental controls,

as they become available.

Section 70.213 For my longwall

operation, when will MSHA approve my

interim ventilation plan incorporating a

PAPR respiratory protection program?

Approval of your interim mine

ventilation plan would depend on the

results of verification sampling and the

operating conditions in effect for each

sample. Paragraph (b) adds additional

criteria or ‘‘critical values’’ for coal mine

dust and quartz dust to those specified

in § 70.209. These additional critical

values, listed in Table IV–2, would

apply to the environments of workers

required to wear PAPRs under the plan.

The critical values given in § 70.209

would continue to apply to DO samples.

However, once an interim ventilation

plan is approved, the position of the DO

will change. Your plan would be

approved if it reflects the dust control

parameters in place during verification

sampling and none of the verification

samples exceed the corresponding

critical values. No DO dust sample

obtained during the verification process

can exceed 2.0 mg/m3 (respirable coal

mine dust) or 100 μg/m3 (respirable

quartz dust). Since we estimate a

protection factor of two, no verification

sample from the environment where

workers are required to wear PAPRs

could exceed 4.0 mg/m3 (coal mine

dust) or 200 μg/m3 (quartz dust).

TABLE IV–2.—CRITICAL VALUES FOR VERIFYING PLAN EFFECTIVENESS IN THE ENVIRONMENT OF WORKERS REQUIRED TO

WEAR PAPRS. THE RESULT OF EACH SAMPLE USED TO VERIFY PLAN EFFECTIVENESS FOR SUCH WORK ENVIRONMENTS MUST BE LESS THAN OR EQUAL TO THE APPROPRIATE CRITICAL VALUE

Number of shifts meeting criteria for verification sampling

Critical value

for coal mine

dust

(μg/m3)

Critical

value for

quartz dust

(μg/m3)

1 ..................................................................................................................................................................................... 3.54 174

2 ..................................................................................................................................................................................... 3.77 187

3 ..................................................................................................................................................................................... 3.89 194

4 or more ....................................................................................................................................................................... 4.0 200

42148 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

Section 70.214 For my longwall

operation, under what circumstances

may I (the operator) continue to use

PAPRs to supplement engineering or

environmental controls?

In order to continue use of PAPRs to

supplement your engineering or

environmental controls, you must

comply at all times with the dust

control provisions of your interim mine

ventilation plan. This includes: (1)

implementing and maintaining all

feasible engineering or environmental

controls on each shift; and (2)

complying with all provisions of your

approved PAPR respiratory protection

program. In addition, to ensure the

continued effectiveness of your

approved dust control parameters, no

DO sample taken by an MSHA inspector

could exceed the applicable dust

standard. Furthermore, no MSHA

measurement for any miner working

downwind of the DO could exceed

twice the applicable dust standard.

Finally, you would be required to

continue to seek improvements and

implement, when they became

available, any feasible engineering or

environmental controls. MSHA will

follow-up on your efforts in this regard

as part of its regular six-month review

of your mine ventilation plan under

§ 75.370.

Respirator programs require

continuous administrative attention to

assure continued effectiveness. MSHA’s

District Manager would evaluate, at

least quarterly, the effectiveness of all

installed engineering or environmental

controls, the effectiveness of your PAPR

respiratory protection program, and

your performance in complying with all

other plan provisions.

Section 70.215 What if an MSHA DO

sample exceeds the applicable dust

standard, or an MSHA sample for a

miner required to wear a PAPR exceeds

twice the applicable dust standard.

This proposed section would require

you to review your dust control

procedures and promptly take action

which would prevent similar

occurrences in the future. Also, you

must review your approved PAPR

respirator program to assure its

continued effectiveness. Dust levels in

excess of the applicable standard could

result from a change in operating

conditions, because of an abnormal

condition or work practice, or due to

production exceeding the VPL. If you

determine that you cannot comply with

the dust standard, you would need to

amend your interim ventilation plan

and submit it to the District Manager for

review and approval.

If you are cited under § 75.371 for

failure to comply with your approved

interim plan, the District Manager may

conduct an investigation to determine if

you are complying with the dust control

provisions of your approved interim

ventilation plan. If the investigation

discloses that you are not following

your plan, MSHA may revoke approval

of your plan.

Finally, the District Manager may

revoke your interim plan and withdraw

permission to use PAPRs for compliance

purposes if you have a record of

noncompliance with your interim

ventilation plan, or if MSHA samples

indicate that miners are not adequately

protected. If this occurs, your revised

interim plan must include a VPL at

which you can comply with the

applicable standard.

Sections 70.216 Through 70.218

Use of Verifiable Administrative

Controls

These sections establish requirements

for using verifiable administrative

controls to supplement engineering or

environmental controls.

Section 70.216 For my longwall

operation, what must I (the operator) do

in order to use verifiable administrative

controls to supplement engineering or

environmental controls?

‘‘Verifiable administrative controls’’

are work practices that reduce miners’

daily exposure to respirable dust by

altering the way in which work is

performed such as rotating miners to

areas having lower concentrations of

respirable dust. To be considered

verifiable administrative controls, it is

necessary that the practices: (1) Can be

reviewed to confirm proper

implementation, (2) are clearly

understood by miners, and (3) can be

applied consistently over time. If you

choose to use verifiable administrative

controls for compliance purposes,

paragraph (a) requires you to submit a

revised ventilation plan to MSHA’s

District Manager within five days of

receiving MSHA’s written approval in

accordance with § 70.211. This plan

must specify: (1) the feasible

engineering or environmental controls

to be used for reducing respirable dust

concentrations to the lowest possible

level; (2) the verifiable administrative

controls to be implemented on the

longwall MMU; and (3) the procedures

to be employed for ensuring compliance

with the verifiable administrative

controls on every shift.

Once MSHA grants provisional

approval, we will verify the

effectiveness of the revised dust control

provisions of the ventilation plan. We

will sample all miners working on the

longwall face, including the DO

(occupation code 044 or other

occupation designated by the District

Manager), to demonstrate effectiveness

of the proposed dust control provisions.

If effectiveness of the plan is verified, it

would become your interim ventilation

plan.

The use of verifiable administrative

controls is not intended to be

permanent. Their use for compliance

purposes would be permitted only on an

interim basis, until feasible engineering

or environmental controls become

available. You would have to implement

any feasible engineering and

environmental controls, as they become

available. You must make sure that you

continue to comply with your approved

administrative controls, and you must

maintain the effectiveness of your

engineering or environmental controls.

Finally, you must implement any

feasible engineering or environmental

controls methods that become available,

and that would prevent full shift dust

concentrations from exceeding the

applicable dust standard at any location

at which miners normally work at the

longwall face.

Section 70.217 For my longwall

operation, when will MSHA approve my

interim ventilation plan incorporating

verifiable administrative controls?

Approval of the dust control

provisions of your interim ventilation

plan depends on the results of your

verification samples and on the actual

operating conditions under which each

sample was taken. None of the samples

obtained during the verification process

may exceed 2.0 mg/m3 (coal mine dust)

or 100 μg/m3 (quartz dust). Under

paragraph (b), MSHA’s District Manager

may approve the dust control provisions

of your interim plan if (1) the plan

reflects all dust controls, including

administrative controls in effect during

verification sampling and (2) none of

the samples used to verify plan

effectiveness exceed the appropriate

critical values as specified and

explained in § 70.209.

Section 70.218 For my longwall

operation with an approved interim

ventilation plan, what if an MSHA

sample exceeds the applicable dust

standard?

Under this section, you must

immediately review your dust control

procedures, including the effectiveness

of your administrative controls, and take

action to prevent similar occurrences in

the future if any MSHA compliance

sample exceeds the applicable dust

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42149

standard. Dust levels in excess of the

applicable standard could result from a

change in operating conditions, because

of an abnormal condition or work

practice, or due to production levels

which exceed the VPL. If changes are

made in your interim ventilation plan,

you must submit them to the District

Manager for review and approval.

If you are cited under § 75.371 for

failure to comply with your approved

plan, the District Manager may conduct

an investigation to determine if you are

complying with the dust control

provisions of your approved interim

ventilation plan. If the investigation

discloses that you are not following

your plan, approval of your plan may be

revoked.

Finally, the District Manager may

revoke your interim plan and withdraw

permission to use administrative

controls for compliance purposes if you

have a record of noncompliance with

your interim ventilation plan, or if

MSHA samples indicate that miners are

not adequately protected. If this occurs,

your revised interim plan must include

a VPL at which you can comply with

the applicable standard.

Actions Necessary When You Are in

Violation of Respirable Dust Standards

Section 70.219 What must I (the

operator) do if I am cited for exceeding

the applicable dust standard?

If you are cited for violating § 70.100

or § 70.101, you would be required to

promptly review your dust control

practices to determine the cause of the

excessive dust concentration. You

would also be required to take

corrective action to prevent miners from

being overexposed in the future by

lowering the concentration of respirable

dust to comply with the applicable dust

standard. You would be required to take

these actions within the abatement

period fixed in a citation.

After reviewing your dust control

practices and taking corrective action,

you would be required to incorporate

changes reflecting these actions into

your ventilation plan in accordance

with § 75.370(a)(2). If, in your opinion,

the corrective actions taken do not

warrant a change in your plan’s dust

control parameters, you would need to

explain that in your response to the

District Manager. This will enable the

District Manager to determine if the

ventilation plan should be changed and

re-verified.

Based on the dust parameters that

were in use for the results of the

compliance sample(s) dust

concentrations measured by MSHA

samples, and the information submitted

by the operator regarding the type(s) of

corrective action that were taken, MSHA

may elect to sample the cited entity to

determine the effectiveness of your

abatement actions. If these samples

indicate compliance with the applicable

dust standard, you would be required to

incorporate your corrective actions in

your mine ventilation plan. At a

minimum you would be required to

incorporate in your plan the actual

parameters that were in effect when

MSHA sampled. If the MSHA samples

indicate continued noncompliance, then

MSHA may revoke approval of your

ventilation plan.

Information To Be Posted on the Mine

Bulletin Board

Section 70.220 What information must

I (the operator) post on the mine bulletin

board?

This proposed section would provide

ready access to current information

relating to the plan verification process

and to the respirable dust conditions in

the mine. You would be required to post

on the mine bulletin board the actual

values of specific dust control

parameters measured by MSHA on

shifts used for plan verification and all

sample results. For the same reason, the

proposal would require that all written

notifications received from the District

Manager regarding any aspect of the

plan verification process. You could

remove the information from the mine

bulletin board after the plan is approved

by the District Manager.

Also, you would also be required to

post the results of MSHA compliance

sampling on the bulletin board. These

results must be posted for at least 31

days. These posting requirements are

intended to promote miner awareness of

the conditions under which the mine

ventilation plan has been shown to be

effective in controlling dust levels in

their work environment. The goal is

consistent with the statutory intent that

miners play a role in preventing

unhealthy conditions and practices

where they work.

Status Change Reports

Section 70.221 What action must I (the

operator) take if the operational status

of my mine, MMU, or DA changes?

In order to conduct verification and

compliance sampling, it is essential that

you provide current information to us

concerning the production status of

MMUs and DAs within those mines that

are in producing status. Therefore, to

reduce the chances of visiting a mine

whose operating status prevents the

MSHA inspector from sampling, you

would continue to be required to report

the change in operational status of the

mine, MMU, or DA to the MSHA

District Office or to any other MSHA

office designated by the District

Manager. You would also be required to

report a change in operational status if

it would affect the verification sampling

requirements under this proposal.

Status changes would be reported in

writing within three working days after

the status change occurred. The

reporting of changes in operational

status is not a new requirement and is

contained in existing § 70.220. MSHA is

renumbering existing § 70.220 as

§ 70.221.

Changes to Part 75

Section 75.370 Mine Ventilation Plan;

Submission and Approval

This proposal would amend § 75.370

by adding a new paragraph (h).

Paragraph (h) would require that records

of the amount of material produced each

production shift by each MMU during

the previous six-month period be made

available for inspection by authorized

representatives of the Secretary and the

miners’ representative.

These records are essential for the

plan verification process. The records

are needed to establish the verification

production level (VPL) required under

proposed § 75.371(f) and to confirm that

the 30-shift period on which the VPL is

based represents typical production

conditions for the MMU. Additionally,

MSHA and the miners’ representative

need these records to monitor changes

in production levels that may affect the

plan’s adequacy. Finally, because

verification of a plan’s effectiveness is

conditioned on the VPL, these records

are necessary to determine if the VPL

used in approving a plan continues to

reflect typical production levels at the

mine.

The production records for each

MMU may be maintained in any form

utilized by the operator to measure the

total amount of material produced, so

long as the method is the same as that

used to establish the VPL required for

plan verification. For example: number

of loaded shuttle cars, feet of advance,

raw tonnage, or number of longwall

passes would each be an acceptable

method of recording production—so

long as the same method was

consistently used.

Section 75.371 Mine Ventilation Plan;

Contents

The proposal would revise paragraphs

(f) and (t). Existing paragraph (f) would

be revised to require the ventilation

plan to include any specific work

practices used to minimize the dust

42150 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

exposure of individual miners,

information on the location of the roof

bolter(s) during the mining cycle for

each continuous miner section, and the

cut sequence for each longwall mining

section.

Also, every ventilation plan would be

required to include information on the

length of each normal production shift

and to specify the VPL as defined in

§ 70.2. Although a VPL would be

included in the ventilation plan, MSHA

would not cite you for producing at

levels exceeding the VPL. We would

expect production on an MMU to

exceed the VPL on about 33 percent of

all production shifts. If the District

Manager determines that your

production exceeds the VPL on more

than 33 percent of the production shifts

over a six-month period, then this may

trigger the plan verification process

using a higher VPL.

For interim plans involving the use of

powered, air purifying respirators

(PAPRs) or verifiable administrative

controls, the plan must also include the

information respectively required under

§ 70.212(b) or § 70.216(a). This

additional information is necessary to

fully assess the adequacy of mine

ventilation plans.

Since MSHA is proposing to revoke

existing §§ 70.207 and 70.208 which

require sampling by mine operators,

existing paragraph (t) would be revised

to remove the provision that mine

operators identify in the mine

ventilation plan the locations where

samples for designated areas (DA) will

be collected, including the specific

location of each sampling requirement,

and the reference to § 70.208. However,

to ensure that the mine atmosphere

where miners are normally required to

work or travel is continuously

maintained in compliance, proposed

paragraph (t) would continue to require

mine operators to identify in the mine

ventilation plan the location of each DA,

defined in proposed § 70.2(e), and the

particular dust control measures that

would be used at the dust generating

sources for these locations. These

locations would continue to be sampled

by MSHA inspectors as discussed

earlier (see Background Section) to

determine compliance with the

applicable standard and to assess the

adequacy of the operator’s dust control

measures.

Part 90

The proposed rule would revoke all

operator sampling requirements

associated with coal miners who have

evidence of the development of

pneumoconiosis under Part 90. MSHA

is republishing the entire regulatory text

of Part 90 as it would appear under the

proposal for ease of review. Aside from

a few technical clarifications which are

described below, the only change to Part

90 would be to remove all references to

operator sampling.

Section 90.1 Scope.

The scope of part 90 would not

change under the proposal. However,

the phrase ‘‘including respirable dust

sampling for Part 90 miners’’ would be

removed from the end of the sentence

which states that ‘‘the rule also sets

forth the operator’s obligations.’’

Section 90.2 Definitions.

All definitions would remain

unchanged under the proposal with the

exception of those for ‘‘concentration’’

and ‘‘mechanized mining unit’’ which

have been clarified as described below.

The definition for ‘‘valid respirable dust

sample’’ would be removed because

mine operators would no longer collect

Part 90 samples under the proposal. No

discussion has been included below if

the definition would not change under

the proposal. For ease of reference,

subsection references have been added

for each definition.

Concentration is a measure of the

amount of substance contained per unit

volume of air.

The existing definition would be

modified so that ‘‘concentration’’ refers

to an 8-hour Mining Research

Establishment (MRE) equivalent

measure of the amount of sampled

material contained per unit volume of

air. The proposed revision would

include the constant factor of 1.38

which the Secretary currently uses to

convert concentration of respirable dust

measured with approved sampling

devices to an equivalent concentration

as measured with an MRE instrument.

The existing coal mine dust standards

were developed from 8-hour shift

exposure measurements. Therefore, if a

sample is taken over a period other than

eight hours, the concentration

measurement must be adjusted to be

equivalent to an eight-hour exposure.

This is necessary in order to provide

equal protection to miners working

shifts greater than eight hours and

would be accomplished by multiplying

the sampler flow rate by 480 minutes,

regardless of the length of time that the

sample was actually collected.

For this example, suppose a DO

sample is collected over a 9-hour shift

that includes one hour of travel time.

Suppose that the amount of dust

accumulated during travel is negligible,

and the amount accumulated during

production is 1.5 mg. If the

concentration were not adjusted to an 8-

hour equivalent, it would be diluted by

the time spent traveling and calculated

as 1.92 mg/m3. Under the proposed

definition, the calculated concentration

would be 2.16 mg/m3.

The proposed definition does not

change the daily limit on accumulated

exposure intended by the existing

exposure limit for coal mine dust. Since

the current limit was based on an

assumption that exposure occurs over

an 8-hour shift, it corresponds to a daily

cumulative exposure limit of 8 × 2.0 =

16 mg-hr/m3. The proposed definition

of concentration would maintain this

same MRE-equivalent 16 mg-hr/m3

daily limit, regardless of the length of

any shift worked.

To continue the example, the

exposure accumulated during a day is

the same, whether from 8 hours at an

average of 2.16 mg/m3 or from 9 hours

at an average of 1.92 mg/m3. In either

case, the MRE-equivalent exposure

accumulated for the day is 17.3 mg-hr/

m3, which exceeds the intended daily

limit of 16 mg-hr/m3. Under the

proposed definition, this would be

reflected by the fact that the calculated

concentration exceeds 2.0 mg/m3.

MSHA solicits comments on this

method of adjusting concentrations to

an 8-hour equivalent.

Mechanized mining unit has been

revised to refer to the proposed rule new

§ 70.205. The definition also clarifies

that each MMU is assigned a four digit

identification number by MSHA. The

MMU retains the identification number

regardless of where the unit relocates

within the mine. When two sets of

mining equipment are provided in a

series of working places and only one

production crew is employed at any

given time on either set of mining

equipment, the two sets of equipment

are to be identified as a single MMU.

When two or more MMUs are

simultaneously engaged in the

production of material within the same

working section, each such MMU is

identified separately.

Section 90.100 Respirable dust

standard.

The Part 90 respirable dust standard

would not change. Since MSHA would

collect all Part 90 samples under the

proposal, the sentence which provides

that ‘‘concentrations shall be measured

with an approved sampling device and

expressed in terms of an equivalent

concentration determined in accordance

with § 90.206’’ would be removed.

Section 90.101 Respirable dust

standard when quartz is present.

Because MSHA would collect all Part

90 samples, this section would be

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42151

changed by removing the sentence

which provides that ‘‘concentrations

shall be measured with an approved

sampling device and expressed in terms

of an equivalent concentration

determined in accordance with

§ 90.206.’’

An example has been added to

explain how a reduced standard is

established when respirable dust

associated with a part 90 miner contains

quartz in the amount of 20%.

Section 90.102 Transfer; notice.

This section would remain

unchanged.

Section 90.103 Compensation.

This section would remain

unchanged.

Section 90.104 Waiver of rights; reexercise of option.

This section would remain

unchanged.

Section 90.201 MSHA Respirable dust

sample reports; Operator status change

reporting requirement.

Under the proposal, mine operators

would no longer collect respirable dust

samples under Subpart C of Part 90.

Consequently, all of Subpart C,

‘‘Sampling Procedures,’’ including

§§ 90.201–209 would be removed.

Existing § 90.210 would be renumbered

as § 90.201. The requirements of this

section would remain unchanged.

Section 90.202 Operator status change

reports.

Under the proposal, mine operators

would no longer collect respirable dust

samples under Subpart C of Part 90.

Consequently, all of Subpart C,

‘‘Sampling Procedures,’’ including

§§ 90.201–209 would be removed.

Existing § 90.220 would be renumbered

as § 90.202. The requirements of this

section would remain unchanged.

Section 90.300 Respirable dust control

plan; filing requirements.

There would be no change in the

filing requirements for respirable dust

control plans under the proposal.

Section 90.301 Respirable dust control

plan; approval by District Manager;

copy to part 90 miner.

There would be no change in the

approval process or notice requirements

for respirable dust control plans under

the proposal.

V. Health Effects

A. Introduction

Since the 1800s, occupational

respiratory disease associated with

working in a coal mine has been

commonly referred to as ‘‘Black Lung.’’

As coal is mined, respirable-sized dust

is generated. Depending upon the mine

location and its geologic features, silica

may also be present in the mine

atmosphere. Dust in air that is breathed

by miners has the potential to be

deposited in their lungs. Some of this

dust may be retained. Coal mine dust

remaining in the lungs of miners for

prolonged periods of time has the

potential to result in respiratory

diseases, sometimes even after

occupational exposure to respirable coal

mine dust has stopped. There is a clear

and direct relationship between miners’

cumulative exposures (i.e., dose

multiplied by the time exposed to the

coal mine dust) to respirable coal mine

dust and the severity of resulting

respiratory conditions (as discussed

more extensively, later in this section).

Diseases resulting from long-term

retention of coal mine dust in the lung

include chronic coal workers’

pneumoconiosis (simple CWP),

progressive massive fibrosis (PMF),

silicosis, and chronic obstructive

pulmonary disease (COPD) (e.g., asthma,

chronic bronchitis, emphysema).

Historically, the medical term,

‘‘pneumoconiosis,’’ has included simple

CWP and PMF and their sub-categories.

Chronic, or simple, CWP is partitioned

into three levels of severity, proceeding

from lowest to highest: category 1,

category 2, and category 3. Progressive

Massive Fibrosis is similarly divided

into three categories of increasing levels

of severity: A, B and C.

Miners with simple CWP have a

substantially increased risk of

developing PMF. In the advanced stages

of pneumoconiosis (i.e., PMF), a

significant loss of lung function may

occur and respiratory symptoms (e.g.,

breathlessness, wheezing) may persist.

Miners are at risk of increased morbidity

and premature mortality due to simple

CWP, PMF and various other respiratory

diseases.

Factors that are important in the

development of simple CWP, PMF and

COPD include the type of dust (e.g., coal

and/or silica), dust concentration (to

which the miner was exposed), number

of years of exposure, age of the miner

(often measured as age at time of

medical examination), and rank of the

coal (the higher the rank the greater the

risk).

In 1998, MSHA estimated that

approximately 45,000 miners and

39,000 miners were employed at

underground and surface coal mines,

respectively (Mattos, 1999). A small

percentage of the mining involved

anthracite coal, the highest rank coal,

while most involved bituminous coal

which is a medium rank coal.

There are complementary data

sources, described below, which

provide estimates of the prevalence of

occupational respiratory disease among

coal miners. Together these data

demonstrate the progress over the last

thirty years in the reduction of

occupational respiratory disease among

coal miners, as well as the need for

further action to reduce occupational

lung disease among today’s coal miners.

Estimates of the prevalence of simple

CWP and PMF among the underground

coal miners are gathered from the x-ray

program, through which operators are

required to provide miners the

opportunity to be evaluated periodically

for the presence of occupational lung

disease, mandated pursuant to Section

203(a) of the Mine Act (30 U.S.C.

843(a)). However, miners are not

required to participate. From 1970 to

1995, the prevalence of simple CWP and

PMF among miners participating in the

mandated x-ray program has dropped

from 11 percent to 3 percent (MSHA,

Internal Chart, 1998).

In accordance with 30 CFR part 50,

those cases of occupational illnesses

which both surface and underground

coal mine operators learn of must be

reported to MSHA. Under this

requirement, mine operators reported

224 cases of pneumoconiosis (simple

CWP and PMF, combined) in 1998

(Mattos, 1999). Of these, 138 cases

occurred among coal miners who

worked underground, while the

remaining 86 cases occurred among

surface coal miners (Mattos, 1999).

There were also 14 cases of silicosis,

eight in underground mines, reported to

MSHA in 1998 in accordance with 30

CFR part 50 (Mattos, 1999). Since

miners participate in both these

programs at their own discretion, these

data do not include the occupational

health experience of all coal miners.

The prevalence of occupational lung

disease among participating miners may

significantly differ from the prevalence

among non-participants. Thus, the data

from these programs may not be

representative of the true magnitude of

the prevalence of simple CWP and PMF

among today’s coal miners.

In the 1990s, MSHA conducted a

series of one-time medical surveillance

programs, in various regions of the

country, to develop a more accurate

estimate of the prevalence of simple

CWP and PMF. Through these special

programs, MSHA tried to minimize

obstacles which may prevent some

miners from either participating in or

reporting to operators the results of

respiratory diagnostic procedures. Nine

42152 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

geographical cohorts of miners, from

around the country, were encouraged to

participate in an independent x-ray

program (MSHA, Internal Chart, 1999).

These cohorts included eight active

surface coal mining communities in the

states of Pennsylvania, Kentucky and

West Virginia, as well as the towns of

Poteau, Oklahoma and Gillette,

Wyoming. A ninth cohort included

underground miners in Kentucky. The

process was designed to encourage

miner participation by providing for a

greater degree of anonymity than may be

available under the program provided

by Section 203(a) of the Mine Act (30

U.S.C. 843(a)). Across the eight surface

cohorts surveyed, the prevalence rate of

simple CWP and PMF combined, among

participants was 4.8%. The prevalence

rate among the participating

underground Kentucky miners was

9.2%.

Also, as part of its ongoing effort to

‘‘end black lung now and forever,’’

beginning in October 1999, MSHA

implemented a pilot program to provide

miners at both surface and underground

mines with confidential health

screening. Referred to as the ‘‘Miners’

Choice Health Screening,’’ the program

addresses the key recommendations of

the Secretary’s Advisory Committee by

(1) increasing participation toward the

85-percent level and (2) expanding the

scope of the eligibility to include

surface coal miners and surface coal

mine independent contractors. The pilot

program operates separately from the

existing Coal Workers’ X-ray

Surveillance Program administered by

NIOSH. Since the Miners’ Choice Health

Screenings’ inception, over 7,000

miners have been screened, with the

participation rate in most areas

exceeding 50 percent. With half of the

x-rays taken during the first six months

having been processed by NIOSH,

preliminary results indicate a

prevalence rate of approximately 2.25

percent.

The National Institute for

Occupational Safety and Health

(NIOSH) and the Mine Safety and

Health Administration (MSHA) are

concerned about the prevalence of

occupational lung disease among

today’s miners. Epidemiological studies

from the U.S. and abroad have

consistently shown that underground

and surface coal miners are at risk of

developing simple CWP, PMF, silicosis,

and chronic obstructive pulmonary

disease (NIOSH Criteria Document,

1995).

B. Hazard Identification

1. Agent: Coal

Coal is a fossil fuel derived from

partial degradation of vegetation.

Through its combustion, energy is

produced which makes coal a valuable

global commodity. It has been estimated

that over one-third of the world uses

energy provided by coal (Manahan,

1994). Approximately 1,800

underground and surface coal mines are

in operation in the United States

annually producing slightly over a

billion short tons of coal (Mattos, 1999).

Coal may be classified on the basis of

its type, grade, and rank. The type of

coal is based upon the plant material

(e.g., lignin, cellulose) from which it

originated. The grade of coal refers to its

chemical purity. Although coal is

largely carbon, it may also contain other

elements such as hydrogen, oxygen,

nitrogen, and sulfur. ‘‘Hard’’ coal refers

to coal with a higher carbon content

(i.e., 90–95%) than ‘‘soft’’ coal (i.e., 65–

75%). Coal rank relates to geologic age,

indexed by its fixed carbon content,

down to 65%, and then by its heating

value. Volatile matter varies inversely

with the fixed carbon value. The most

commonly described coal ranks include

lignite (low rank), bituminous coal

(medium rank), and anthracite (high

rank) (Manahan, 1994).

2. Physical State: Coal Mine Dust

Aerosols are a suspension of solid or

liquid particles in air (Mercer, 1973);

they may be dusts which are solid

particles suspended in the air. Coal dust

may be freshly generated or may be resuspended from surfaces on which it is

deposited in mines. As discussed below,

coal mine dust may be inhaled by

miners, depending upon the particle

size.

Coal mine dust is a heterogenous

mixture, signifying that all coal particles

do not have the same chemical

composition. The particles are

influenced by the type, grade, and rank

of coal from which they were generated

(Manahan, 1994). Irrespective of

differences in coal characteristics, these

dusts are water-insoluble, which is

important biologically and

physiologically. Unlike soluble dusts

which may readily pass into the

respiratory system and be cleared via

the circulatory system, insoluble dusts

may remain in the lungs for prolonged

periods of time. Thus, a variety of

cellular responses may result that could

eventually lead to lung disease.

3. Biological Action: Respirable Coal

Mine Dust

The principal route of occupational

exposure to respirable coal mine dust

occurs via inhalation. As a miner

breathes, coal mine dust enters the nose

and/or mouth and may pass into the

mid airways (e.g., bronchi, terminal

bronchioles) and lower airways (e.g.,

respiratory bronchioles, alveolar ducts).

Coal mine dust has a size distribution

that is estimated to range between 1 and

100 micrometer (μm) (1 μm = 10¥6 m)

(Silverman, et al., 1971). The size of coal

particles is critical in determining the

level of the respiratory tract at which

deposition and retention occur

(American Conference of Governmental

Industrial Hygienists, 1999; American

Industrial Hygiene Association, 1997).

Particles that are above 10 μm are

largely filtered in the nasal passages,

although some of these particles may

reach the thoracic (or trachealbronchial) region of the lung (e.g., 6%

of 20 μm) (American Conference of

Governmental Industrial Hygienists,

1999). Thus, there is evidence that

‘‘oversized’’ particles (i.e., >10 μm) can

move beyond the nose, deeper into the

respiratory tract. Particles below 10 μm

may easily move throughout the

respiratory tract. As particle size

decreases from 10 to 5 μm, however,

there is greater penetration into the mid

and lower regions of the lung. Particles

that are approximately 1–2 μm are the

most likely to be deposited in the lung

(American Conference of Governmental

Industrial Hygienists, 1999; Mercer,

1973). During mouth breathing, there

may be a slight upward shift in the

particle deposition curve such that 2–3

μm-sized particles are the most likely to

be deposited in the respiratory tract

(Heyder, et al., 1986). Irrespective of

nasal or mouth breathing, the potential

respiratory tract penetration of particles

whose size is approximately 10 μm or

less is important because particles in the

respirable size range deposit in the deep

lung where clearance is much slower.

For the purposes of this rule,

‘‘respirable dust’’ is defined as dust

collected with a sampling device

approved by the Secretary of Labor and

the Secretary of the Department of

Health and Human Services (DHHS) in

accordance with 30 CFR Part 74 (Coal

Mine Dust Personal Sampler Units). In

practice, the coal mine dust personal

sampler unit has been used in the U.S.

The particles collected with an

approved sampler approximate that

portion of the dust which may be

deposited in the lung (West, 1990;

1992). It does not, however, indicate

pulmonary retention (i.e., those

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42153

particles remaining in the lung). For

those particles that are deposited in the

lung, clearance mechanisms normally

operate to assist in their removal. For

example, within the thoracic (trachealbronchial) region of the lung, cilia (i.e.,

hairlike projections) line the airways

and are covered by a thin layer of

mucus. They assist in particle clearance

by beating rhythmically to project

particles toward the throat where they

may be swallowed, coughed, sneezed, or

expectorated. This rhythmic beating

action is effective in removing particles

fairly quickly (i.e., hours or days).

Within the alveolar region of the lung,

particles may be engulfed by pulmonary

macrophages. These large ‘‘wandering

cells’’ may remove particles via the

blood or lymphatics. This process,

unlike the movement of the cilia is

much slower (i.e., months or years).

Thus, some particles, particularly those

that are insoluble, may remain in the

alveolar region for long periods of time,

despite the fact that pulmonary

clearance is not impaired. It is the

pulmonary retention of coal mine dust

which may be the impetus for

respiratory disease.

It is also important to note that silica

may be present in the coal seam, within

dirt bands in the coal seam, and in rock

above and below coal seams. Of the

silica found in coal mines, quartz is the

form which is found. Thus, quartz may

become airborne during coal removal

operations (Manahan, 1994). Miners

may inhale dust that is a mixture of

quartz and coal. MSHA is concerned

with the inhalation of quartz since it

may be deposited in the lungs of miners

and produce silicosis. This is a

restrictive lung disease which is

characterized by a stiffening of the lungs

(West, 1990; 1992). Silicosis has been

seen in coal miners (e.g., surface miners,

drillers, roofbolters) (Balaan, et al.,

1993). Silicosis may develop acutely

(i.e., 6 months to 2 years) following

intense exposure to high levels of

respirable crystalline quartz. Silicosis

has also been observed in coal miners

following chronic exposure (i.e., 15

years or more), but may be accelerated

(i.e., 7–10 years) in some cases (Balaan,

et al., 1993). Silicosis is irreversible and

may lead to other illnesses and

premature mortality. People with

silicosis have increased risk of

pulmonary tuberculosis infection and

an increased risk of lung cancer

(Althouse, et al., 1995; International

Agency for Research on Cancer, 1997).

MSHA’s current standard of 2.0 mg/m3

for respirable coal dust requires that

quartz levels be 5% or lower. Otherwise,

the 2.0 mg/m3 respirable coal dust

exposure limit does not apply and must

be adjusted downward for percent

quartz. If coal dust contains more than

5% quartz, then the following formula

is applied (30 CFR 70.101; 30 CFR

71.101):

Respirable dust standard (mg/m3) = [(10

mg/m3)/(%Quartz)]

The intent of this formula is to maintain

miner exposures to quartz below 0.1

mg/m3 (100 μg/m3).

C. Health-Related Effects of Respirable

Coal Mine Dust

1. Description of Major Health Effects

Consistently, epidemiological studies

have demonstrated miners to be at risk

of developing respiratory symptoms, a

loss of lung function, and lung disease

as a consequence of occupational

exposure to respirable coal mine dust.

As noted previously, risk factors include

type(s) of dust, dust concentration,

duration of exposure, age of the miner

(often measured as age at time of

medical examination), and coal rank.

a. Simple Coal Workers’

Pneumoconiosis (Simple CWP) and

Progressive Massive Fibrosis (PMF). In

earlier stages of pneumoconiosis the

term, ‘‘simple coal workers’

pneumoconiosis’’ (simple CWP), has

been used, while in more advanced

stages, the terms ‘‘complicated CWP’’

and PMF have been used

interchangeably. Simple CWP and PMF

involve the lung parenchyma and are

produced by deposition and retention of

respirable coal dust in the lung.

To determine if a miner has simple

CWP or PMF, chest x-rays are taken and

classified by a certified radiologist or

reader. Opacities are identified on chest

films and then classified using a scale

of 0–3 (e.g., simple CWP category 1),

where higher category values indicate

increasing concentration of opacities. In

some instances, two category values

may be given. For example, simple CWP

category 2⁄3 signifies that the reader

decided the film was category 2, but

suspected that it might have been

category 3. The International Labour

Office (ILO) has provided a full

description of the criteria for these

classifications (ILO, 1980).

Simple CWP can be associated with a

loss of lung function and with

premature mortality (Morgan, et al.,

1974; Jacobsen, 1976; Cochrane, et al.,

1979; Parkes, 1982). MSHA recognizes

that simple CWP increases the risk of

developing PMF substantially

(Cochrane, 1962; Jacobsen, et al., 1971;

McLintock, et al., 1971; Balaan, et al.,

1993).

Progressive massive fibrosis (PMF) is

associated with decreased lung function

and increased premature mortality

(Rasmussen, et al., 1968; Atuhaire, et

al., 1985; Miller and Jacobsen, 1985;

Attfield and Wagner, 1992). Progressive

massive fibrosis is also associated with

increases in respiratory symptoms such

as chest tightness, cough, and shortness

of breath. Miners with PMF also have an

increased risk of acquiring infections

and pulmonary tuberculosis (Petsonk

and Attfield, 1994; Yi and Zhang, 1996).

Finally, miners with PMF have an

increased risk of right-side heart failure

(i.e., cor pulmonale) (Cotes and Steel,

1987).

b. Other Health Effects. During a

medical examination, a miner may be

questioned by his physician about

symptoms such as cough, phlegm

production, chest tightness, shortness of

breath, and wheezing. Occupational

physicians may also conduct pulmonary

function tests using spirometry or

plethysmography. Pulmonary

performance may be assessed via

repeated measurements of lung volumes

and capacities, such as the forced

expiratory volume in one second (FEV1),

vital capacity (VC), forced vital capacity

(FVC), residual volume (RV), and total

lung capacity (TLC) (West, 1990; 1992).

Changes in lung volumes and capacities

may indicate a loss of the integrity of

the lung (i.e., respiratory system). More

importantly, they can provide

information for diagnosis of diseases

affecting the airways and/or elasticity of

the lung (i.e., obstructive vs. restrictive

lung disease)(West, 1990; 1992).

The term, chronic obstructive

pulmonary disease (COPD), refers to

three disease processes that are often

difficult to properly diagnose and

differentiate: chronic bronchitis,

emphysema, and asthma (Coggon and

Taylor, 1998; Garshick, et al., 1996;

West, 1990; 1992). As indicated by

several studies, the exposure of miners

to respirable coal mine dust place them

at increased risk of developing COPD.

Furthermore, COPD may occur in

miners with or without the presence of

simple CWP or PMF.

Chronic Obstructive Pulmonary

Disease (COPD) is characterized by

airflow limitations, and thus there is a

loss of pulmonary function. As in

simple CWP or PMF, a miner with

COPD may have a variety of respiratory

symptoms (e.g., shortness of breath,

cough, sputum production, and

wheezing) and may be at increased risk

of acquiring infections. Chronic

Obstructive Pulmonary Disease is

associated with increased premature

mortality (Hansen, et al., 1999; Meijers,

et al., 1997).

Briefly, in chronic bronchitis and in

asthma, there is excess mucous

42154 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

secretion in the mid-lower airways

(West, 1990; 1992). In contrast,

emphysema is characterized by

dilatation (enlargement) of alveoli that

are distal to the terminal bronchioles,

which leads to poor gas exchange (i.e.,

poor transfer of oxygen and carbon

dioxide). Additionally, there is a

breakdown of the interstitium between

the alveoli. These pathological changes

may be confirmed upon autopsy. With

asthma, the airflow limitations may be

partially or completely reversible, while

they are only partially reversible with

chronic bronchitis and emphysema.

The Mine Safety and Health

Administration (MSHA) and the NIOSH

recognize that respiratory symptoms,

loss of lung function, and COPD may

impair the ability of a miner to perform

his job and may diminish his quality of

life. Additionally, miners having such

health effects are at increased risk of

morbidity (e.g., from cardio-pulmonary

disease, infections) and premature

mortality.

2. Toxicological Literature

To better understand the human

health effects of exposure to respirable

coal mine dust and to more fully

characterize the associated risks, it is

important to consider data that have

been obtained in animal based

toxicological studies. To date, sub-acute

studies (a study with a duration of 30

days, or less, in which multiple

exposures of the same agent are given)

and chronic studies (a study with a

duration of more than 3-months, in

which multiple exposures of same agent

are given) attempted to mimic miners’

exposures. Inhalation was generally the

route of exposure, although several

studies have also employed instillation

techniques (i.e., a method which places

a known quantity of dust into the

trachea or bronchi).

Most recent toxicological studies have

been short-term studies, largely focusing

on ‘‘lung overload’’ (Sipes, 1996;

Oberdorster, 1995; Morrow, 1988, 1992;

Witschi, 1990), species-dependent lung

responses (Nikula, et al., 1997a,b;

Mauderly, 1996; Lewis, et al., 1989;

Moorman, et al., 1975), and particle

size-dependent lung inflammation

(Soutar, et al., 1997). The data have

shown that pulmonary clearance of

particles may become impaired,

potentially leading to inflammatory and

other cellular responses in the lung.

Although overloading has not been

demonstrated in humans, the finding of

reduced lung clearance among retired

U.S. coal miners (Freedman and

Robinson, 1988) is consistent with this

possibility.

The data from Moorman, et al. (1975),

Lewis, et al. (1989), and Nikula, et al.

(1997a,b) are noteworthy for several

reasons. First, these groups of

investigators conducted chronic

inhalation toxicity studies (i.e., chronic

bioassays). This is important since

miners’ exposures also occur via

inhalation, and over a working lifetime.

Secondly, the investigators used an

exposure concentration of 2.0 mg/m3 in

their bioassays. As noted above, this is

the current MSHA standard for

respirable coal mine dust. Thirdly, the

exposures involved nonhuman

primates, whose responses are thought

to closely mimic those of man. Some of

the key findings of these studies

included: deposition of coal dust in the

animals’ lungs, retention of coal dust in

alveolar tissue, altered lung defense

mechanisms, reduced pulmonary

airflows, and hyperinflation of the

lungs. One of the shortcomings of these

studies is that complete dose-response

relationships were not developed.

However, at higher exposure

concentrations, greater effects may be

expected which is a basic tenet of

toxicology. Thus, at exposure

concentrations above 2.0 mg/m3, MSHA

and NIOSH believe that more severe

obstructive lung disease may occur.

3. Epidemiological Literature

Epidemiology studies have

consistently demonstrated the serious

health effects of exposure to high levels

of respirable coal mine dust (i.e., above

2.0 mg/m3) over a working lifetime.

Table V–1 lists epidemiology studies

since 1986 whose results will be

discussed on the basis of the type of

observed health effect. Studies

completed even earlier including the

early work of Cochrane (1962),

McLintock, et al. (1971), and Jacobsen,

et al. (1971) demonstrated the adverse

health effects (e.g., simple CWP, PMF)

of respirable coal mine dust in British

coal miners.

Both early and recent studies have

shown that the lung is the major target

organ (i.e., organ in which toxic effects

occur) when exposure to respirable coal

mine dust occurs. As seen in Table V–

1, numerous studies of miners have

been conducted. Recent U.S. studies

were conducted using data from one or

more of the first four rounds of the

National Study of Coal Workers’

Pneumoconiosis (NSCWP), and have

provided extensive data on miners’

health. Many of these studies

demonstrated that miners are at

increased risk of multiple, concurrent

respiratory ailments (Attfield and

Seixas, 1995; Kuempel, et al., 1997;

Meijers, et al., 1997; Seixas, et al., 1992).

TABLE V–1.—RESPIRABLE COAL MINE DUST EPIDEMIOLOGICAL STUDIES, BY REPORTED OUTCOMES FROM 1986 TO

PRESENT

Studies Reported outcomes

Meijers, et al.,1997 .................................................................................................................................................................. PMF, CWP, COPD,

LLF

Maclaren, et al.,1989 ............................................................................................................................................................... PMF, CWP, LLF, RS

Kuempel*, et al.,1995 .............................................................................................................................................................. PMF, CWP, COPD

Bourgkard et al.,1998 .............................................................................................................................................................. PMF, CWP, LLF

Kuempel*, et al.,1997

Love, et al.,1997

Love, et al.,1992

Attfield and Morring*,1992b ..................................................................................................................................................... PMF, CWP

Attfield and Seixas*, 1995

Hodous and Attfield*, 1990

Hurley and Jacobsen, 1986

Hurley and Maclaren, 1987

Hurley, et al., 1987

Starzynski, et al., 1996

Yi and Zhang, 1996

Wang, et al.,1997 .................................................................................................................................................................... CWP, LLF

Goodwin and Attfield*, 1998 .................................................................................................................................................... CWP

Morfeld, et al., 1997

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42155

TABLE V–1.—RESPIRABLE COAL MINE DUST EPIDEMIOLOGICAL STUDIES, BY REPORTED OUTCOMES FROM 1986 TO

PRESENT—Continued

Studies Reported outcomes

Marine, et al.,1988 ................................................................................................................................................................... COPD, LLF, RS

Seixas*, et al., 1993

Soutar and Hurley, 1986

Carta, et al.,1996 ..................................................................................................................................................................... LLF, RS

Henneberger and Attfield*, 1997

Henneberger and Attfield*, 1996

Seixas*, et al., 1992

Attfield and Hodous*, 1992 ...................................................................................................................................................... LLF

Lewis, et al., 1996

COPD: Chronic obstructive pulmonary disease

CWP: Simple coal workers’ pneumoconiosis

LLF: Loss of lung function

PMF: Progressive massive fibrosis

RS: Respiratory symptoms

*: Studies of U.S. Miners Who Participated in the National Study of Coal Workers’ Pneumoconiosis (NSCWP)

a. Simple Coal Workers’

Pneumoconiosis (Simple CWP) and

Progressive Massive Fibrosis (PMF).

Studies following Cochrane (1962) and

McLintock et al. (1971) have confirmed

that the risk of PMF increases with

increasing category of simple CWP

(Hurley and Jacobsen, 1986; Hurley, et

al., 1987; Hurley and Maclaren, 1988;

Hodous and Attfield, 1990). However,

the risk of PMF was greater than

previously predicted among miners

with simple CWP category 1 or without

simple CWP (i.e., category 0) (Hurley, et

al., 1987). The risk of PMF increased

with increasing cumulative exposure,

regardless of the initial category of

simple CWP (Hurley, et al., 1987),

indicating that reducing dust exposures

is a more effective means of reducing

the risk of PMF than reliance on

detection of simple CWP.

Attfield and Seixas (1995) have

demonstrated a relationship between

cumulative exposure to respirable coal

mine dust and predicted prevalence of

pneumoconiosis (i.e., simple CWP,

PMF). They studied a group of

approximately 3,200 men who worked

in underground bituminous coal mines.

The U.S. miners and ex-miners had

participated in Round 1 (1970–1972) or

Round 2 (1972–1975) of the NSCWP and

were examined again between 1985 and

1988. Chest x-rays were read to

determine the number of cases of simple

CWP and PMF. Dust exposure estimates

were generated from measurements of

dust concentrations as well as from

work history. A logistic (or logit)

regression model was used to estimate

prevalence of simple CWP and PMF. In

this statistical analysis, proportions are

transformed to natural logarithmic

values, i.e., y = ln [p/(1¥p), before a

linear model is fit to the data (Armitage,

1977). The logistic model assumes that

the data have a binomial distribution

(e.g., presence or absence of PMF) for a

given set of covariate values (e.g., age,

coal rank, dust exposure, pack-years of

smoking). Using logistic modeling,

relationships were developed between

cumulative dust exposure and

prevalence of simple CWP (category 1+,

category 2+) and PMF. These

relationships were the key strengths of

the Attfield and Seixas study and serve

as the basis for the Quantitative Risk

Assessment of this rule.

The recent paper of Kuempel, et al.

(1997) has provided a detailed

discussion and quantitative presentation

of excess risks associated with

respirable coal dust exposures. Their

study was based upon results from

previous studies of some 9,000

underground coal miners who

participated in the NSCWP (Attfield and

Morring, 1992b; Attfield and Seixas,

1995). Kuempel, et al. estimated excess

(exposure-attributable) prevalence of

simple CWP and PMF (i.e., number of

cases of disease present in a population

at a specified time, divided by the

number of persons in the population at

that specified time). Point estimates of

excess risk of PMF ranged from 1/1000

to 167/1000 among miners exposed at

the current MSHA standard for

respirable coal mine dust. These

estimates were based upon dust

exposure that occurred over a miner’s

working lifetime (e.g., 8 hours per day,

5 days a week, 50 weeks per year, over

a period of 45 years). Actual

occupational lifetime exposure may be

more, due to extended work shifts and

work weeks. The point estimates of PMF

presented by Kuempel, et al. (1997)

were related to coal rank, where higher

estimates (e.g., 167/1000) were obtained

for high-rank coal (anthracite coal) and

somewhat lower estimates were

obtained for medium/low rank

bituminous coal (e.g., 21/1000). Within

each coal rank, the estimates of simple

CWP cases were at least twice as high

as those for PMF (e.g., 167/1000 PMF vs.

380/1000 simple CWP≥1).

The data of Attfield and Seixas (1995)

and Kuempel, et al. (1995; 1997) were

consistent with previous data of Attfield

and Morring (1992b) who reported

relationships between estimated dust

exposure and predicted prevalence of

simple CWP or PMF. They also noted

that exposure-response relationships

were steeper for higher ranks of coal

such as anthracite, and concluded that

the risks for anthracite miners appeared

to be greater than for miners exposed to

lower rank coal dust. Attfield and

Morring (1992b) used similar methods

as described above (i.e., logistic

modeling), but included miners from

Round 1 of the NSCWP (1969-1971);

thus representing an earlier time point

in the NSCWP when the respirable coal

mine dust concentrations were much

higher than they are today.

Recently, Goodwin and Attfield

(1998) reported that there were concerns

regarding methodological

inconsistencies across surveys given

during the four rounds of the NSCWP.

In particular, they noted the

discordance in classification of simple

CWP and PMF among readers of chest

films. Despite potential discordance,

Goodwin and Attfield (1998) have

confirmed previous findings of a decline

in simple CWP prevalence from 1969 to

1988. Yet, these analyses also

demonstrated that simple CWP has not

been eliminated. The Round 4

prevalence rates were 3.9 percent for

simple CWP category 1 and higher, and

0.9 percent for category 2 and higher.

This illustrates the need for continued

efforts to reduce dust exposures.

Given the current system for

monitoring exposures and identifying

overexposures in the U.S., miners are at

42156 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

increased risk of developing simple

CWP and PMF from a working lifetime

exposure to respirable coal mine dust

(Kuempel, et al. 1997, 1995; Attfield

and Seixas, 1995; Goodwin and Attfield,

1998; Attfield and Morring, 1992b).

Whenever overexposures (i.e.,

excursions above the applicable

standard) occur, the long-term mean

exposure of miners may be increased,

thereby causing an upward shift on the

exposure-response curve. Such a shift

then places these overexposed coal

miners at increased risk of developing

and dying prematurely from simple

CWP and PMF.

The Attfield and Seixas

epidemiological study (1995) is the most

appropriate to use in estimating the

benefit of reduction of overexposures.

The authors applied scientific rigor to

the collection, categorization, and

analyses of the radiographic evidence

for the group of 3,194 underground

bituminous coal miners who

participated in Round 4, 1985–1988, of

the National Study of Coal Workers’

Pneumoconiosis (NSCWP); this study

population excludes 86 miners for

whom there was missing exposure data

or unreadable x-rays. Radiologic

evidence was carefully collected and

analyzed by multiple independent,

NIOSH certified B readers to identify

stages of simple CWP and PMF. In the

targeted population of 5,557 miners, the

participating miners (3,280) were

similar to the non-participants (2,277)

with regard to age at the first medical

examination and prevalence of simple

CWP category 1 or greater. The nonparticipants had worked slightly longer,

yet had lower prevalence of simple CWP

category 2 or greater, than the

participants. This study describes the

differences among current miners and

ex-miners (health-related or job-related)

in the relationships between the

estimated cumulative exposure to

respirable coal mine dust and

prevalence of simple CWP category 1 or

greater. Such data and relationships

were not available in other U.S. studies

and non-U.S. studies.

A potential limitation in the U.S.

studies is the possible bias in the

exposure data, which has been the

subject of several studies (Boden and

Gold, 1984; Seixas et al., 1991; Attfield

and Hearl, 1996). An advantage of the

Attfield and Seixas 1995 study (and the

earlier studies based on the same data

set) is that the larger mines included in

these epidemiological studies were

shown to have exposure data with

relatively small bias (Attfield and Hearl,

1996). Another limitation in exposure

data used in the U.S. studies is that the

airborne dust concentrations used to

estimate individual miners’ cumulative

exposures to respirable coal mine dust

were based on average concentrations

within job category (these average

values were combined with data of each

individual miner’s duration employed

in a given job). The earlier U.S.

exposure-response studies of miners

participating in the first medical survey

of the NSCWP (Attfield and Morring,

1992b; Attfield and Hodous, 1992;

Kuempel, et al., 1995) relied primarily

on exposure measurements from a dust

sampling survey during 1968–1969 to

estimate miners’ exposures before 1970

(Attfield and Morring, 1992a). An

advantage of the Attfield and Seixas

1995 study is that, in addition to the

pre-1970 exposure estimates, more

detailed exposure data were available to

estimate miners’ exposures from 1970 to

1987, during which the mean airborne

concentrations were stratified by mine,

job, and year (Seixas, et al., 1991).

The most complete exposure data

available are those for coal miners in the

United Kingdom (Hurley, et al., 1987;

Hurley and Maclaren, 1987; Soutar and

Hurley, 1986; Marine, et al., 1988;

Maclaren, et al., 1989). These studies

include medical examinations and

individual estimates of exposure for

more than 50,000 miners for up to 30

years. The U.S. studies are consistent

with these U.K. studies in

demonstrating the risks of developing

occupational respiratory diseases from

exposure to respirable coal mine dust.

These risks increase with increasing

exposure concentration and duration,

and with exposure to dust of higher

ranked coal. The quantitative

assessment of risk and associated

benefits were based on the Attfield and

Seixas (1995) study because, in addition

to the advantages described above, it

best represents the recent conditions

experienced by miners in the U.S. This

quantitative assessment follows in

Section VI. The international studies

provide an important basis for

comparison with the U.S. findings, and

several of the recent international

studies are described in detail here.

Bourgkard, et al. (1998) conducted a

4-year study of a group of French coal

miners who were employed in

underground and surface mines. The

investigators examined the prognostic

role of cumulative dust exposure,

smoking patterns, respiratory

symptoms, lung CT scans, and lung

function indices for chest x-ray

worsening and evolution to simple CWP

and PMF. Bourgkard, et al. (1998),

through selection of a younger worker

population (i.e., 35–48 years old at start

of study), attempted to focus on the

early stages of simple CWP. In essence,

they hoped to identify those miners who

needed to be relocated to less dusty

workplaces or who needed to be

clinically monitored. Bourgkard, et al.

(1998) concluded that there was an

association between cumulative dust

exposure and what was termed chest xray ‘‘worsening’’ (i.e., increase in readerdesignated category signifying

progression of simple CWP). Their

conclusion, however, was based on

pooling of the data (i.e., three combined

groups of miners) who had different

cumulative exposures (i.e., 20, 66 and

85 mg-yr/m3).

Love, et al. (1997, 1992) reported on

occupational exposures and the health

of British opencast (i.e., surface or strip)

coal miners. They studied a group of

approximately 1,200 miners who were

employed at sites in England, Scotland,

and Wales. The mean age of the men

was 41; many had worked in the mining

industry since the 1970s. To determine

dust exposure levels, full shift personal

samples were collected. Most were

respirable dust samples which were

collected using Casella cyclones

according to the procedures described

by the British Health and Safety

Executive (HSE). Thus exposure

determinations would be comparable to

exposure determinations obtained in

U.S. surface coal mines since both

measure respirable dust according to the

BMRC criteria.

These investigators found a doubling

in the relative risk of developing

profusion of simple CWP category 0/1

for every 10 years of work in the

dustiest jobs in surface mines. These

respirable coal dust exposures were

under 1 mg/m3. Love, et al. (1992,

1997), like other investigators,

emphasized the need for monitoring and

controlling exposures to respirable coal

mine dust, particularly in high risk

operations (e.g., drillers, drivers of

bulldozers).

Meijers, et al. (1997) studied Dutch

coal miners who were examined

between 1952 and 1963, and who were

followed until the end of 1991. They

reported an increased risk of mortality

from simple CWP and PMF among

miners who had generally worked

underground for 20 or more years. Their

conclusions were based upon dramatic

increases in standardized mortality

ratios (SMRs). There were several

limitations in this study, however.

Morfeld, et al. (1997) published a

recent paper that investigated the risk of

developing simple CWP in German

miners and addressed the occupational

exposure limit for respirable coal dust

in Germany. Their study included

approximately 5,800 miners who

worked underground from the late

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42157

1970s to mid-1980s. Morfeld, et al.

observed increases in relative risks

(RRs) of developing early x-ray changes,

category 0/1, that were exposuredependent. Relative risks (RRs)

increased with higher dust

concentrations.

Starzynski, et al. (1996) conducted a

mortality study on a group of 11,224

Polish males diagnosed with silicosis,

simple CWP, or PMF between 1970 and

1985. This cohort was subdivided by

occupation into four subcohorts: coal

miners (63%); employees of

underground work enterprises (8%) (i.e.,

drift cutting and shaft construction

jobs); metallurgical industry and iron,

and nonferrous foundry workers (16%);

and refractory materials, china, ceramics

and quarry workers. The investigators

found that coal miners had a slight,

statistically significant excess overall

mortality (i.e., all causes) as indicated

by a Standardized Mortality Ratio (SMR)

of 105 (with a 95% Confidence Interval

(C.I.) of 100–110). Also, excess of deaths

from diseases of the respiratory system

among coal miners was nearly four

times that of the referent population

(SMR of 383 with a 95% C.I. of 345–

424). The study of Starzynski, et al.

(1996) agrees with others that there is

premature mortality among coal miners

from simple CWP and PMF.

Unfortunately, there is little or no

information presented on miner work

history, exposure assessment (e.g.,

respirable coal mine dust, silica), and

mine environment (e.g., coal rank(s),

underground vs. surface mining).

Yi and Zhang (1996) conducted a

study to measure the progression from

simple CWP to PMF or death among a

cohort of 2,738 miners with simple CWP

who were employed at the Huai-Bei coal

mine in China. Relative risks (i.e., RRs)

were calculated for progression from

simple CWP category 1 to simple CWP

category 3 and for progression from

simple CWP category 3 to death. Their

results demonstrated that miners with

simple CWP category 1 are at risk of

developing simple CWP category 2 and

simple CWP category 3 (e.g., RRs of

1.101 and 2.360, respectively). They

also found that miners with PMF had a

decreased life expectancy. Other risk

factors for development of PMF

included long-term work underground,

and drilling. This study was limited by

a lack of exposure assessment,

estimation of miner smoking histories,

and use of a radiological classification

system that differs from that of the ILO.

Hurley and Maclaren (1987) studied

British coal miners who were examined

between 1953 and 1978, over 5-year

intervals. They have shown that

exposure to respirable coal dust

increases the risks of developing simple

CWP and of progressing to PMF. As

seen in their data analysis, these

responses were dependent upon dust

concentration and coal rank. That is,

greater responses were seen at higher

dust concentrations and with higher

rank coal (i.e., increasing per cent

carbon. The investigators also noted that

estimated risks were unaffected by

changes in the proportion of miners

with simple CWP who transferred jobs.

The authors concluded that ‘‘limiting

exposure to respirable coal dust is the

only reliable way of limiting the risks of

radiological changes to miners.’’

b. Other Health Effects. As noted in

Table V–1, there were 16 studies in

which the loss of lung function (LLF)

was examined in coal miners. Six of

these studies also included an

evaluation of respiratory symptoms (RS)

in the miners. There were five studies

describing chronic obstructive

pulmonary disease (COPD) in miners.

Henneberger and Attfield (1997;

1996), Kuempel, et al. (1997), Seixas, et

al. (1993), Attfield and Hodous (1992),

and Seixas, et al. (1992) evaluated data

from pulmonary function tests and

standardized questionnaires to miners

in the NSCWP. A common finding in

their studies was an increase in

respiratory symptoms such as cough,

shortness of breath, and wheezing. The

symptoms were dependent upon the

dust concentration to which the miners

had been exposed, with more

pronounced symptoms occurring after

long-term exposures to higher exposure

levels. These studies also demonstrated

that a loss of lung function occurred

among miners.

Attfield and Hodous (1992) studied

U.S. miners who had spent 18 years

underground (on average) and who

participated in Round 1 (1969–1971) of

the NSCWP. They observed that greater

reductions in pulmonary function were

associated with exposure to higher

ranks of coal (i.e., anthracite vs.

bituminous vs. lignite). Using linear

regression models, Kuempel et al.,

(1997) predicted the excess (exposure

attributable) prevalence of lung function

decrements among miners with

cumulative exposures to respirable coal

mine dust of 2 mg/m3 for 45 years (i.e.,

90 mg-yr/m3). The excess prevalence

estimated were 315 and 139 cases per

thousand for forced expiratory volume

in one second (FEV1) of <80% and

<65% of predicted normal values,

respectively, among never-smoking

miners (a sub-group of 977 NSCWP

participants studied in Seixas et al.,

1993). Such reductions in (FEV1 are

clinically significant; (FEV1 <80% (of

predicted normal values) is a measure

that is used to determine ventilatory

defects (American Thoracic Society,

1991). Three recent studies found

impaired (FEV1 to be a predictor of

increased pre-mature mortality (Weiss,

et al., 1995; Meijers, et al., 1997; Hansen

et al., 1999).

Seixas, et al. (1993) conducted an

analyses of 977 underground coal

miners who began working in or after

1970 and were participants of both

NSCWP Round 2 (1972–1975) and

Round 4 (1985–1988). They found a

rapid loss of lung function in miners

and further declines in lung function

with continuing exposure to coal mine

dust. Collectively these studies have

shown that the prevalence of decreased

lung function was proportional to

cumulative exposure. That is, with

exposure to higher coal dust levels over

a working lifetime, there were more

miners who experienced a loss of lung

function. Also, the types of respiratory

symptoms and patterns of pulmonary

function decrements observed by both

Attfield and Hodous (1992) Seixas, et al.

(1992;1993) are characteristic of COPD.

The U.S. findings on respiratory

symptoms and loss of lung function in

miners have agreed with those of

previous British studies by Marine, et

al. (1988) and Soutar and Hurley (1986).

Marine, et al. (1988) analyzed data from

British coal miners and focused their

attention on respiratory conditions other

than simple CWP and PMF. In

particular, they examined the Forced

Expiratory Volume in one second (FEV1)

among smoking and nonsmoking miners

and, on the basis of reported respiratory

symptoms, identified those miners with

bronchitis. Using these data, logistic

regression models were used to estimate

the prevalence of chronic bronchitis and

loss of lung function. Marine, et al.

concluded that both exposure to

respirable coal mine dust and smoking

independently cause decrements in lung

function; their contributions to COPD

appeared to be additive in coal miners.

Soutar and Hurley (1986) examined

the relationship between dust exposure

and lung function in British coal miners

and ex-miners. The men who were

studied were employed in coal mines in

the 1950s and were followed up and

examined 22 years later. These miners

and ex-miners were categorized as

smokers, ex-smokers, or nonsmokers.

The Forced Expiratory Volume in one

second (FEV1), the Forced Vital

Capacity (FVC), and the (FEV1/FVC)

ratios decreased in all study groups and

these reductions in lung function were

inversely proportional to dust exposure.

Thus, Soutar and Hurley concluded that

exposure to respirable coal mine dust

can cause severe respiratory

42158 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

10Forced vital capacity (FVC) is the total volume

of gas that can be exhaled with a forced expiration

after a full inspiration; The vital capacity measured

with a FVC may be less than that measured with

a slower exhalation (West, 1992).

impairment, even without the presence

of simple CWP or PMF. They speculated

that the pathology of coal dust-induced

lung disease differs from that induced

by smoking.

Recent studies from China (Wang, et

al., 1997) and the European community

(Bourgkard, et al., 1998; Carta, et al.,

1996; Lewis, S., et al., 1996) have also

supported the British and U.S. findings

which demonstrated the correlation

between occupational exposure to coal

dust and respiratory symptoms and loss

of lung function in miners.

Wang, et al. (1997) examined lung

function in underground coal miners

and other workers from several other

factories in Chongqing, China. For their

study, information was obtained on

exposure duration, results of

radiographic tests, and smoking history.

Pulmonary function tests were

performed, providing the Forced

Expiratory Volume in one second

(FEV1), the Forced Vital Capacity (FVC),

and (FEV1/FVC) data. Additionally, the

diffusing capacity for carbon monoxide

(DLCO) was measured. This is an

indicator of diffusion impairment at the

‘‘blood-gas barrier’’ which may occur,

for example, when this barrier becomes

thickened (West, 1990; 1992). Wang, et

al. (1997) found that there was

impairment of pulmonary function

among the coal miners and they had

evidence of obstructive disease. Like

other studies, such effects were

observed among coal miners even in the

absence of simple CWP. Pulmonary

function was further decreased when

simple CWP was present. This study did

not provide exposure measurements and

there was no consideration of exposureresponse relationships. Also, silica

exposures and their potential effects

were not examined in the underground

coal miners.

As noted above, Bourgkard, et al.

(1998) was interested in the earlier

stages of simple CWP (i.e., Categories 0/

1 and 1/0) and the prognostic role of

cumulative dust exposure, smoking

patterns, respiratory symptoms, lung CT

scans, and lung function indices for

chest x-ray worsening and evolution to

simple CWP category 1/1 or higher.

Over a 4-year period, they studied

French coal miners who were employed

in underground and surface mines.

Bourgkard, et al. (1998) found that, at

the first medical examination, the ratio

of the Forced Expiratory Volume in one

second (FEV1) to the Forced Vital

Capacity (FVC) (i.e., (FEV1/FVC) and

other airflows determined from a forced

expiration (West, 1990; 1992) were

lower among miners who later

developed simple CWP category 1/1 or

higher. These miners also experienced

more wheezing at the first medical

examination. Thus, the results of their

study suggested that lung function

changes may serve as an early indicator

of miners who are at increased risk of

developing simple CWP and PMF and

who should be monitored more closely.

Carta, et al. (1996) have examined the

role of dust exposure on the prevalence

of respiratory symptoms and loss of

lung function in a group of young Italian

coal miners (i.e., mean age at hire 28.9

years, mean age at first survey 31.2

years). These miners worked

underground and were exposed to

lignite (i.e., low rank coal) which had a

5–7% sulfur content. They were

followed for a period of 11 years, from

1983 and 1993. Carta, et al. (1996) found

few abnormalities on miner chest x-rays

taken throughout the 11-year study.

However, there was an increased

prevalence of respiratory symptoms and

loss of lung function. This was

particularly noteworthy since dust

exposures were often below 1.0 mg/m3;

the cumulative dust exposure for the

whole cohort was 6.7 mg-yr/m3 after the

first survey. Thus, Carta, et al. (1996)

demonstrated that miners experience

respiratory effects of exposure to dust

generated from a lower rank coal and at

lower concentrations. They have

recommended yearly measurements of

lung function for miners.

Lewis, et al. (1996) studied a group of

British miners, many of whom entered

the coal industry in the 1970s. Based

upon chest x-rays, the miners had no

evidence of simple CWP or PMF. The

objective of this study was to determine

whether coal mining (i.e., exposure to

respirable coal mine dust) is an

independent risk factor for impairment

of lung function. Lewis, et al. (1996)

found that there was a loss of lung

function in miners (smokers and

nonsmokers), particularly among miners

who were under approximately 55 years

of age. For miners who smoked, there

was a greater loss of lung function than

in nonsmoking miners with the same

level of exposure to respirable coal mine

dust. Above age 55, the loss of lung

function was similar for miners and

their controls, although all smokers

continued to exhibit a greater loss of

lung function than nonsmokers. Lewis,

et al. (1996) concluded that the deficits

in lung function may occur in the

absence of simple CWP and PMF, and

independent from the effects of

smoking.

There have been two recent mortality

studies that have demonstrated a

relationship between exposure to

respirable coal mine dust and

development of COPD. This association

was reported by Kuempel, et al. (1995)

in the U.S., and by Meijers, et al. (1997)

in the Netherlands. These two groups of

investigators have reported that

occupationally-induced COPD (e.g.,

chronic bronchitis, emphysema) can

occur in miners, with or without the

presence of simple CWP or PMF. They

also found that the risk of premature

mortality from COPD was elevated

among miners and could be separated

from the effects of smoking and age.

Kuempel, et al. (1995) found an

increase in relative risk (RR) of

premature mortality from COPD among

U.S. coal miners who participated in the

NSCWP from 1969 through 1971. In

their data analysis, the exposureresponse relationship was evaluated

using the Cox proportional hazards

model. This model assumes that the

hazard ratio between nonexposed and

exposed groups does not significantly

change with time. When fitting a curve

to the data (e.g., log-linear), cumulative

exposure was expressed as a categorical

or continuous variable. Due to model

limitations (e.g., less statistical power,

influence of category scheme, use of

lowest exposure group for comparisons

vs. use of non-exposed group),

Kuempel, et al. (1995) believed that the

exposure data should be expressed as a

continuous variable. If, for example, the

cumulative exposure was 90 mg-yr/m3 (i.e.,

2 mg/m3 for 45 years), then the relative

risk of mortality from chronic bronchitis

or emphysema was 7.67. Kuempel, et al.

(1995) also showed that relative risk

decreased with lower cumulative

exposures (i.e., below 90 mg-yr/m3) and

increased with higher cumulative

exposures (i.e., above 90 mg-yr/m3).

Thus, these investigators demonstrated

a statistically significant exposureresponse relationship for COPD.

Meijers, et al. (1997) have shown,

among Dutch miners, reductions in lung

volumes and capacities are good

predictors of the increased risk of

premature mortality from COPD. For

example, a diminished forced expiratory

volume in one second (FEV1) or a

diminished ratio of the FEV1 to the

forced vital capacity 10 (FVC) (i.e., FEV1/

FVC) upon medical examination was

associated with a significantly increased

standardized mortality ratio (SMR) for

COPD (322 and 212, respectively). In

other words, miners with diminished

lung capacity based on FEV1 were two

to three times more likely to die

prematurely due to COPD than miners

who had normal lung function. In

contrast, SMRs for COPD were not

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42159

11By ‘‘exhibiting a pattern of recurrent

overexposures,’’ MSHA means that, at a 95-percent

confidence level, the applicable standard is

exceeded on at least [six] shifts per year. Using a

different definition of ‘‘recurrent pattern of

overexposures’’ in these analyses would change the

estimate of the reduction in risk and associated

benefits. For example, if the definition were that

four or more DO bimonthly exposure measurements

exceeded the applicable standard, we could state,

with 95% confidence, that the standard was

exceeded on at least 20 shifts in a year of 384 shifts.

This would reduce the population for whom we are

estimating benefits, and decrease the estimated

number of prevented cases by 19%.

12, 13MSHA estimates an MMU average of 384

production shifts per year. Since mine operators are

required to submit five valid designated operator

(DO) samples to MSHA every two months, there

would typically be 30 valid DO samples—

representing 30 of the 384 production shifts—for

each MMU that was in operation for the full year.

If dust concentrations on two or more of the

sampled shifts exceeded the standard, then it

follows, at a 95-percent confidence level, that the

standard was exceeded on at least [six] shifts over

the full year.

significantly increased in miners with

normal lung volumes and capacities.

These data support prior conclusions of

Seixas, et al. (1992, 1993) and Attfield

and Hodous (1992) based on morbidity

studies.

VI. Quantitative Risk Assessment

As mentioned previously, in addition

to this proposed notice of rulemaking,

today’s Federal Register contains

another NPRM, Determination of

Concentration of Respirable Coal Mine

Dust, RIN 1219–AB18. In combination,

these rules present MSHA’s

strengthened plan to meet the Mine

Act’s requirement that a miner’s

exposure to respirable coal mine dust be

at or below the applicable standard on

each and every shift. MSHA’s improved

program to eliminate overexposures on

each and every shift includes the

simultaneous implementation of an

improved tool to identify overexposures

(i.e., inspectors use of single, full–shift

samples for noncompliance

determinations) and this proposed

regulation, requiring operators to verify

ventilation plans in underground coal

mines.

Having reviewed the reported health

effects associated with exposure to coal

mine dust, we have evaluated the

evidence to determine whether the

current regulatory strategy can be

improved. The criteria for this

evaluation is established by the Mine

Act under section 101(a)(6)(A) [30

U.S.C. 811(a)(6)(A)] which provides

that:

The Secretary, in promulgating mandatory

standards dealing with toxic materials or

harmful physical agents under this

subsection, shall set standards which most

adequately assure on the basis of the best

available evidence that no miner will suffer

material impairment of health or functional

capacity even if such miner has regular

exposure to the hazards dealt with by such

standard for the period of his working life.

Based on Court interpretations of

similar language under the

Occupational Safety and Health Act,

there are three questions that must be

addressed: (1) Whether health effects

associated with the current pattern of

overexposures on individual shifts

constitute a material impairment to

miner health or functional capacity; (2)

whether the current pattern of

overexposures on individual shifts

places miners at a significant risk of

incurring any of these material

impairments; and (3) whether the

proposed rules would substantially

reduce those risks.

The criteria for evaluating the health

effects evidence do not require scientific

certainty. The need to evaluate risk does

not mean that an agency is placed into

a ‘‘mathematical straightjacket.’’ See

Industrial Union Department, AFL–CIO

v. American Petroleum Institute, 448

U.S. 607, 100 S.Ct 2844 (1980),

otherwise known as the ‘‘Benzene’’

decision. When regulating on the edge

of scientific knowledge, certainty may

not be possible and,

so long as they are supported by a body of

reputable scientific thought, the Agency is

free to use conservative assumptions in

interpreting the data * * * risking error on

the side of overprotection rather than

underprotection (Id at 656).

The statutory criteria for evaluating the

health evidence do not require MSHA

and NIOSH to wait for absolute

certainty and precision. MSHA and

NIOSH are required to use the ‘‘best

available evidence’’ (section

101(a)(6)(A) of the Mine Act (30 U.S.C.

811(a)(6)(A)).

As explained earlier, MSHA’s

objective in strengthening the

requirements for verifying the

effectiveness of dust control plans, and

in enforcing effective plans through the

new enforcement policy proposed in

this notice, is to ensure that no miner is

exposed to an excessive concentration

(i.e., a concentration in excess of the

applicable standard) of respirable dust

on any individual shift. Annual

inspector samples have demonstrated

overexposures on individual shifts in

many mines. Data compiled from the far

more frequent, bimonthly, operator

sampling program show that in many

mines, the applicable dust standard is

exceeded on a substantial percentage of

the production shifts. This pattern has

persisted for many years, and, since

individual shift excursions above the

applicable standard are permitted under

the existing program, the same pattern

can be expected to continue over the

working lifetime of affected miners—

unless an effort is made to eliminate

excess exposures on individual shifts. In

this quantitative risk assessment (QRA),

MSHA will demonstrate that reducing

coal mine dust concentrations, over a

45-year occupational lifetime, to no

more than the applicable standard on

just that percentage of shifts showing an

excess, thereby lowering the cumulative

exposure to respirable coal mine dust

than would otherwise occur, would

significantly reduce the risk of both

simple CWP and PMF among miners.

We have estimated the health benefits of

the two rules arising from the

elimination of overexposures on all

shifts at only those MMUs exhibiting a

pattern of recurrent overexposures on

individual shifts.11

Based on 1999 operator data, there

were 704 MMUs (out of 1,251 total) at

which dust concentrations for the

designated occupation (DO) exceeded

the applicable standard on at least two

of the sampling shifts (MSHA,

Datafile:Operator.ZIP).12, 13 MSHA

considers these 704 MMUs, representing

more than one-half of all underground

coal miners working in production

areas, to have exhibited a pattern of

recurrent overexposures. Valid operator

DO samples were collected on a total of

18,569 shifts at these 704 MMUs, and

the applicable standard was exceeded

on 3,977 of these shifts, or 21.4 percent.

For this 21.4 percent, the mean excess

above the standard, as measured for the

DO only, was 1.04 mg/m3.

These results are based on a large

number of shifts (an average of

approximately 26 at each of the 704

MMUs). Therefore, assuming

representative operating conditions on

these shifts, the results can be

extrapolated to all production shifts,

including those that were not sampled,

at these same 704 MMUs. With 99-

percent confidence, the overall

percentage of production shifts on

which the DO sample exceeded the

standard was between 20.6 percent and

22.2 percent for 1999. At the same

confidence level, again assuming

representative operating conditions, the

overall mean excess on noncompliant

shifts at these MMUs was between 0.96

mg/m3 and 1.12 mg/m3. If operators

tend to reduce production and/or

increase dust controls on sampled shifts

(as some commenters to the previous

single, full-shift sample rulemaking and

the Dust Advisory Committee have

alleged) then the true values could be

42160 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

higher than the upper endpoints of

these 99-percent confidence intervals.

In 1998, MSHA attempted to enforce

compliance on individual shifts.

Therefore, to compare the 1999 pattern

of excess exposures on individual shifts

to that of previous years under the

current enforcement policy, MSHA

examined the regular bimonthly DO

sample data submitted to MSHA by

mine operators in the eight years from

1990 through 1997. The same three

parameters were considered as

discussed above for 1997: (1) The

percentage of MMUs exhibiting a

pattern of recurrent overexposures, as

indicated by at least two of the valid

measurements above the applicable

standard in a given year; (2) for those

and only those MMUs exhibiting

recurrent overexposures, the overall

percentage of production shifts on

which the DO was overexposed, as

estimated by the percentage of valid

measurements above the applicable

standard; and (3) for the MMUs

identified as exhibiting recurrent

overexposures, the mean excess above

the applicable standard, as calculated

for just those valid measurements that

exceeded the applicable standard in a

given year.

Although MSHA found minor

differences between individual years,

there was no statistically significant

upward or downward trend in any of

these three parameters over the 1990–

1997 time period (see Table VI–1). In

1999, however, there was a significant

decrease in the average excess above the

applicable standard (Parameter #3) for

MMUs exhibiting recurrent

overexposures. MSHA attributes this

decrease to two important changes in

the Agency’s inspection program,

beginning near the end of 1998. These

changes, which both resulted in

increased inspector presence, were: (1)

An increase in the frequency of MSHA

dust sampling at underground coal

mines; and (2) initiation of monthly spot

inspections at mines that were

experiencing difficulty in maintaining

consistent compliance with the

applicable dust standard.

TABLE VI–1.—1990–1997, DISTRIBUTION OF PARAMETERS OF ANNUAL OVEREXPOSURE TO RESPIRABLE COAL MINE

DUST

1990–1997 Parameter #1

(percent)

Parameter #2

(percent)

Parameter #3

(mg/m3)

Number of Years ................................................................................................................... 8 8 8

Median ................................................................................................................................... 52.6 20.5 1.23

Mean (Standard Error) ........................................................................................................... 50.9 20.6 1.25

(1.62) (0.32) (0.020)

Parameter #1: Percentage of MMUs exhibiting a pattern of recurrent overexposures.

Parameter #2: For those MMUs exhibiting a pattern of recurrent overexposures, the percentage of production shifts on which the DO was

overexposed.

Parameter #3: For those MMUs exhibiting a pattern of recurrent overexposures, the mean excess above the applicable standard among valid

DO measurements that exceeded the applicable standard.

MSHA invites public comment on

whether these three parameters, based

on operators’ 1999 samples, underrepresent or over-represent the

frequency and/or magnitude of

excessive dust concentrations on all

individual shifts—including those that

are not sampled. These data suggest

that, unless changes are made to enforce

the dust standard on every shift, the

same average pattern of overexposures

observed in 1999 will persist into the

future. Therefore, we conclude that

without the proposed changes:

• Approximately 56 percent of all

MMUs would continue to have a pattern

of recurrent overexposures on

individual shifts;

• At those MMUs with recurrent

overexposures, full shift average

respirable dust concentrations for the

DO would continue to exceed the

applicable standards on about 21

percent of all production shifts;

• Among those shifts on which DO

exposure exceeds the applicable

standards, the mean excess for the DO

would continue to be approximately 1.0

mg/m3.

If all overexposures on individual

shifts are eliminated, the reduction in

total respirable coal mine dust inhaled

by a miner over a working lifetime will

depend on the following factors: the

average volume of air inhaled on each

shift that would otherwise have

exceeded the applicable standard, the

degree of reduction in respirable dust

concentration in the air inhaled on such

shifts, and the number of such shifts per

working lifetime. If a miner inhales ten

cubic meters of air on a shift (U.S. EPA,

1980), reducing the respirable dust

concentration in that air by 1.0 mg/m3

would result in 10 mg less dust inhaled

on that shift alone. Assuming the miner

works 240 shifts per year, then reducing

inhaled respirable dust by an average of

10 mg on 21 percent of the shifts would

reduce the total dust inhaled by 504 mg

per year, or nearly 22,700 mg over a 45-

year working lifetime:

1.0 mg per m3 of inhaled air

× 10 m3 inhaled air per shift

× 50.4 affected shifts (i.e., 21% of 240)

per work year

× 45 work years per working lifetime

= 22,680 mg less dust inhaled per

working lifetime.

The Secretaries invite comments on

the health benefits expected from

reducing the total coal mine dust

inhaled over a working lifetime by this

amount.

In Section V, the strengths and

weaknesses of various epidemiological

studies were presented, supporting the

selection of Attfield and Seixas (1995)

as the study that provides the best

available estimate of material health

impairment with respect to CWP and

PMF. Two of the distinguishing

qualities of this study are the doseresponse relationship over a miners’

lifetime and the fact that these data best

represent the recent conditions

experienced by miners in the U.S. Using

this relationship it is possible to

evaluate the impact on risk of both

simple CWP and PMF expected from

bringing dust concentrations down to or

below the applicable standard on every

shift. This is the only contemporary

epidemiological study of CWP and PMF

providing such a relationship.

Attfield and Seixas used two or three

B readers to identify the profusion of

opacities using the ILO classification

scheme. If three readings were available,

the median value was used. If two

readings were available, the higher of

the two ILO categories was recorded.

Eighty radiographs were eliminated

because only one reading was available.

The most inclusive category of CWP 1∂

includes simple CWP, categories 1, 2, 3,

as well as PMF. Category CWP 2∂ does

not include simple CWP, category 1, but

does include the more severe simple

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42161

14Since females have a greater life expantancy

than males, expected benefits would increase if the

production of female miners were to increase

substantially in the future.

15 ‘‘affected DO miners’’ include all miners who

work at the 56-percent of MMUs under

consideration and who are exposed to dust

concentrations similar to the DO over a 45-year

working lifetime.

CWP categories, 2 and 3, as well as

PMF. The third category used in their

report was PMF, denoting any category

of large opacities.

Attfield and Seixas (1995) provided

logistic regression models for the

prevalence for CWP 1∂, CWP 2∂ and

PMF as a function of cumulative dust

exposure, expressed as the product of

dust concentration measured in the

mine atmosphere and duration of

exposure at that concentration. These

models can be used to estimate the

impact on miners’ risk of both simple

CWP and PMF of reducing lifetime

accumulated exposure by eliminating

excessive exposures on a given

percentage of individual shifts.

At the MMUs being considered (those

exhibiting a pattern of recurrent

overexposures), bringing dust

concentrations down to no more than

the applicable standard on each and

every production shift would reduce DO

exposures on the affected shifts by an

average of 1.04 mg/m3. Assuming this

average reduction applies to only 21

percent of the shifts, the effect would be

to reduce cumulative exposure, for each

miner exposed at or above the DO level,

by 0.22 mg-yr/m3 over the course of a

working year (i.e., 21 percent of shifts in

one year, times 1.04 mg/m3 per shift).

Therefore, over a 45-year working

lifetime, the benefit to each affected

miner would, on average, amount to a

reduction in accumulated exposure of

approximately 10 mg-yr/m3 (i.e., 45

years times 0.22 mg-yr/m3 per year). If,

as some miners have testified, operator

dust samples submitted to MSHA tend

to under-represent either the frequency

or magnitude (or both) of individual full

shift excursions above the applicable

standard, then eliminating such

excursions would provide a lifetime

reduction of even more than 10 mg-yr/

m3 for each exposed miner.

The Attfield and Seixas models

predict the prevalence of CWP 1∂, CWP

2∂, and PMF for miners who have

accumulated a given amount of

exposure, expressed in units of mg-yr/

m3, by the time they attain a specified

age. Benefits of reducing cumulative

exposure can be estimated by

calculating the difference between

predictions with and without the

reduction. For example, suppose a

miner begins work at age 20 and retires

at age 65. By the year of retirement, that

miner is expected to accumulate nearly

10 mg-yr/m3 less exposure if individual

shift excursions are eliminated. For 65-

year-old miners, reducing accumulated

dust exposure by a total of 10 mg-yr/m3

reduces the predicted prevalence of

CWP 1∂ by at least 11 per thousand

(See Table VI–2).

This 11 per thousand, however,

applies only to miners of age 65. The

Attfield and Seixas models provide

different predictions for each year of age

that a miner attains. The predicted

benefit turns out to be smaller for

younger miners and larger for older

miners. This is partly because younger

miners will have accumulated less

exposure reduction from the proposed

changes, and partly because the Attfield

and Seixas models depend directly on

age as well as on cumulative exposure.

The health effects of recurrent

overexposures can occur long after the

overexposures occurred. Even after a

miner retires and is no longer exposed

to respirable coal mine dust, the extra

risk attributable to an extra 10 mg-year/

m3, accumulated earlier, continues to

increase with age. Consequently, the

benefit to be gained from eliminating

individual shift excursions also

continues to increase after a miner is no

longer exposed. For example, assuming

no additional exposure after age 65, the

predicted reduction in average

prevalence of CWP1∂ increases from 12

per thousand at age 65 to 17 per

thousand at age 70. Presumably, the

increasingly greater predicted reduced

risk of disease after age 65 is due to the

latent effects of the reduction in earlier

exposure.

To project the benefits of the two

rules expected from eliminating

overexposures on individual shifts,

MSHA applied the Attfield and Seixas

models to a hypothetical population of

miners who, on average, begin working

at age 20 and retire at age 65, assuming

different lifetimes. The risks for three

different ages have been presented to

show a range of risk depending on the

lifetime: 65, 73, and 80 years. During the

45 ‘‘working years’’ between 20 and 65,

the lifetime benefit accumulates at a rate

of 0.22 mg-yr/m3 of reduced exposure

per year, reaching a maximum of about

10 mg-yr/m3 at age 65. Between ages 65

and 80, the accumulated reduction in

dust exposure remains at an estimated

average of 10 mg-yr/m3, but the benefit

in terms of both simple CWP and PMF

risk continues to increase, as explained

previously.

The expected lifetime for all

American males conditional on their

having reached 20 years of age, is 73

years (calculated from: U.S. Census

March 1997, Table 18; U.S. Census

March 1997, Table 119).14 On average,

the best estimate of the lifetime benefit

to exposed miners is expressed by the

reduction in prevalence of disease at age

73. Carrying out the calculation at a 73-

year average lifetime, MSHA expects

that, at the MMUs under consideration,

bringing dust concentrations down to no

more than the applicable standard on

each shift will:

• Reduce the combined risk of simple

CWP and PMF by at least 18 cases per

1000 affected DO miners; 15

• Reduce the combined risk of simple

CWP (category 2 and 3) and PMF by at

least 9.8 cases per 1000 affected DO

miners;

• Reduce the risk of PMF by at least

5.1 cases per 1000 affected DO miners.

Presented in the first row of Table VI–

2 are the average reductions in risk for

simple CWP and PMF combined, and

PMF alone, over an occupational

lifetime, among affected DO miners who

live to ages 65, 73, and 80, who have

worked at an MMU exhibiting a pattern

of recurrent overexposures. Across

health outcomes, the benefit due to the

predicted reduction in cumulative

exposure to respirable coal mine dust,

through limiting miners’ exposure to no

more than the applicable standard on

each and every shift, increases with age.

When the dust concentration

measured for the DO exceeds the

applicable standard, measurements for

at least some of the other miners may

also exceed the standard on the same

shift, though usually by a lesser amount.

Furthermore, although the DO

represents the occupation most likely to

receive the highest exposure, other

miners working in the same MMU may

be exposed to even higher

concentrations than the DO on some

shifts. Therefore, in addition to the

affected DO miners, there is a

population of other affected miners who

are also expected to experience a

significant reduction in risk as a result

of eliminating overexposures on their

individual shifts.

To estimate how many miners other

than the DO would be substantially

affected, MSHA examined the results

from all valid dust samples collected by

MSHA inspectors in underground

MMUs during 1999 (MSHA, Data file:

Inspctor.zip). Within each MMU, the

inspector typically takes one full-shift

sample on the DO and, on the same

shift, four or more additional samples

representing other occupations. On 896

shifts, at a total of 450 distinct MMUs,

the DO measurement exceeded the

applicable standard and there were at

least four valid measurements for other

42162 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

16With 95-percent confidence, on shifts for which

the DO measurement exceeds the standard, the

mean number of other occupational measurements

also exceeding the standard is at least 1.11.

17With 95-percent confidence, the mean excess is

at least 0.72 mg/m3.

18There are an estimated 7 non-DO miners for

each DO miner, and an average of 1.2 of these 7

miners are overexposed.

occupations available for comparison.

There was an average of 1.2 non-DO

measurements in excess of the standard

on shifts for which the DO measurement

exceeded the standard.16 For non-DO

measurements that exceeded the

standard on the same shift as a DO

measurement, the mean excess above

the standard was approximately 0.8 mg/

m3.17

Combining these results with the 21-

percent rate of excessive exposures

observed for the DO on individual

shifts, it is reasonable to infer that, at

the MMUs under consideration, an

average of 1.2 other miners, in addition

to the one classified as DO, is

overexposed on at least 21 percent of all

production shifts. Over the course of a

working year, the reduction in exposure

expected for these other miners is 0.17

mg-yr/m3 (i.e., 21 percent of one year,

times 0.8 mg/m3).

To assess the reduction in risk

expected from eliminating all singleshift exposures for faceworkers

experiencing lower exposures than the

DO, MSHA again applied the Attfield

and Seixas models to miners who begin

working at age 20, retire at age 65,

assuming various lifetimes: 65, 73, and

80 years. This time, however, the

resulting decrease in predicted

prevalence was multiplied by 1.2/

7=0.171, to reflect the fact that the

assumed rate of overexposure applies,

on average, to about 17 percent of the

faceworkers not classified as the DO.18

In the second row of Table VI–2, we

see that over an occupational lifetime,

the beneficial average reduction in risk

for simple CWP and PMF combined,

and for PMF alone, increases with age.

However, the magnitude of the risk

reduction is smaller for the affected

non-DOs than the affected DOs. This is

expected because the estimated

probability that a non-DO will be

overexposed on a given shift is only 17

percent of the corresponding probability

for the DO. Based on this calculation for

the MMUs under consideration, the

predicted reduction in risk for

faceworkers other than the DO who live

an expected lifetime of 73 years is at

least: 2.3 fewer cases of PMF or simple

CWP per thousand affected miners; 1.3

fewer cases of PMF or simple CWP,

categories 2 or 3, per thousand affected

miners; and 0.7 fewer cases of PMF per

thousand affected miners.

Various data, assumptions and

caveats were used to conduct the

quantitative risk assessment and

benefits analyses. Therefore, we request

any information which would enable us

to conduct more accurate analyses of the

estimated health benefits of the single,

full-shift sample rule and plan

verification rule, both individually and

in combination.

TABLE VI–2.—BY AGE, AVERAGE REDUCTION IN RISK OF OCCUPATIONAL RESPIRATORY DISEASE PER 1,000 AFFECTED

UNDERGROUND COAL MINERS EXPECTED TO RESULT FROM IMPLEMENTATION OF SINGLE, FULL-SHIFT SAMPLE AND

PLAN VERIFICATION

Type of miner

Reduction in risk of occupational respiratory disease per 1,000 affected miners

Simple CWP,a (categories

1, 2 or 3) or PMF b

Simple CWP (categories 2

or 3) or PMF PMF

Age Age Age

65 73 80 65 73 80 65 73 80

Affected Designated Occupation Miners c ....................... 11.0 18.0 25.0 3.7 9.8 21.0 1.8 5.1 12.0

Affected Non-Designated Occupation Miners d ............... 1.4 2.3 3.3 0.5 1.3 2.7 0.2 0.7 1.5

aSimple CWP: Simple coal workers’ pneumoconiosis.

bPMF: Progressive massive fibrosis.

cAffected Designated Occupation (DO) Miners: Includes all miners who work at the 56-percent of the Mechanized Mining Units under consideration and who are exposed to dust concentrations similar to the DO, over a 45-year occupational lifetime. dAffected Non-Designated Occupation (Non-DO) Miners: Includes all underground faceworkers under consideration who are not classified as

the DO.

VII. Significance of Risk

The criteria for evaluating the

evidence to determine whether these

proposed standards improve the

regulatory strategy for controlling

exposures to respirable coal mine dust

are established by the Mine Act

pursuant to section 101(a)(6)(A) (30

U.S.C. 811(a)(6)(A))which provides that:

The Secretary, in promulgating mandatory

standards dealing with toxic materials or

harmful physical agents under this

subsection, shall set standards which most

adequately assure on the basis of the best

available evidence that no miner will suffer

material impairment of health or functional

capacity even if such miner has regular

exposure to the hazards dealt with by such

standard for the period of his working life.

Based on Court interpretations of

similar language under the

Occupational Safety and Health Act,

there are three questions that must be

addressed: (1) Whether health effects

associated with the current pattern of

overexposures on individual shifts

constitute a material impairment to

miner health or functional capacity; (2)

whether the current pattern of

overexposures on individual shifts

places miners at a significant risk of

incurring any of these material

impairments; and (3) whether the

proposed rules would substantially

reduce those risks.

The statutory criteria for evaluating

the health evidence do not require

MSHA to wait for absolute certainty and

precision. MSHA is required to use the

‘‘best available evidence’’ (section

101(a)(6)(A) of the Mine Act (30 U.S.C.

811(a)(6)(A)). The need to evaluate risk

does not mean that an agency is placed

into a ‘‘mathematical straightjacket.’’

See Industrial Union Department, AFLCIO v. American Petroleum Institute,

448 U.S. 607, 100 S.Ct 2844 (1980),

otherwise known as the ‘‘Benzene’’

decision. When regulating on the edge

of scientific knowledge, certainty may

not be possible and,

so long as they are supported by a body of

reputable scientific thought, the Agency is

free to use conservative assumptions in

interpreting the data . . . risking error on the

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42163

19Following terminology used in the Benzene

Decision, a ‘‘conservative’’ assumption is one that

results in more protection for miners than a less

conservative assumption. Therefore, estimated

benefits are greater under assumptions that are

‘‘conservative’’ in this sense.

20By ‘‘exhibiting a pattern of recurrent

overexposures,’’ means that, at a 95-percent

confidence level, the applicable standard is

exceeded on at least six shifts per year.

21 Valid MSHA inspector samples require

production to be at least 60-percent of the average

production for the last 30-days. Valid operator

bimonthly samples must be taken on a normal

production shift (i.e., a production shift during

which the amount of material produced in an MMU

is at least 56 percent of the average production

reported for the last set of five valid samples) (30

CFR 70.101).

22Therefore assuming representative operating

conditions on these shifts, in our QRA the results

were extrapolated to all production shifts, including

those that were not sampled, at those same 704

MMUs.

side of overprotection rather than

underprotection (Id at 656).

We have taken steps in our

quantitative risk assessment to conduct

a balanced analysis using available data.

Some of our assumptions were

conservative, others were not.19

In identifying the number and

percentage of MMUs exhibiting a

pattern of recurrent overexposures on

individual shifts we chose to include

only those MMUs with two or more

1999-operator bimonthly samples in

excess of the applicable standard, rather

than the population of MMUs with any

overexposures.20 Also, the Quantitative

Risk Assessment estimates of reduction

in risk are averages across MMUs

exhibiting a pattern of recurrent

overexposures. For those miners who

work at mines exhibiting a pattern of

recurrent overexposures which differs

from the one applied in the Quantitative

Risk Assessment, their reduction in risk

would be more than or less than the

expected average, depending on

whether or not their overexposures are

at a higher or lower than average rate

and intensity.

Another important decision impacting

choice in this risk assessment involves

the use of the traditional coal miner

work schedule of 48-weeks per year.

Many of today’s miners work longer

hours per day, month, and year than the

traditional work schedule. These longer

work hours increase miners’ cumulative

exposure to respirable coal mine dust

beyond the parameters of exposure used

in our estimates of risk. Even so, to the

extent that a proportion of miners may

have a more limited work schedule (and

occupational exposure), either in

number of years, weeks per year, or

hours per week, their expected benefit

would have to be adjusted downward,

all other variables being constant.

Also, because of heavy, physical

work, some miners may work at

ventilatory rates in excess of the abovecited 10 cubic meters per 8-hour shift;

an estimate of this ventilatory rate is

13.5 cubic meters per 8-hour shift (ICRP,

1994). The sub-population of miners

with higher breathing rates would

inhale more respirable coal mine dust

than would otherwise occur given the

same environmental exposures, thereby

increasing their risks for the

development of simple CWP and PMF.

In the QRA, to estimate average

reduction in exposure, we chose the

best available data sets: 1999 operator

bimonthly samples for DOs and NDOs,

respectively. Currently, both operator

bimonthly and inspector samples 21 may

be taken on production shifts that may

not reflect typical production levels. 22

Although other factors may mediate the

amount of airborne respirable dust such

as, ventilation and water sprays, on

average, higher production is correlated

with increased quantities of airborne

respirable coal mine dust (Webster, et

al., 1990; Haney, et al., 1993; O’Green,

et al., 1994). Some previous commenters

and the Dust Advisory Committee have

alleged that operators tend to reduce

production and/or increase dust

controls on sampled shifts. To the

extent that our values underestimate the

true reduction in respirable coal mine

dust exposures, we have underestimated

the benefits of these rules.

Based on MSHA’s and NIOSH’s

experience and expertise, and previous

comments, we believe the production

levels observed on sampling shifts are

indeed lower than typical (See

discussion in Benefits section). We also

believe at some MMUs, more

engineering controls at higher levels of

efficacy are used during sampling shifts

than on the majority of shifts (See

discussion in Benefits section). Thus, it

is reasonable to conclude that the

number of MMUs exhibiting a pattern of

recurrent overexposures is greater than

the 704 captured in this Quantitative

Risk Assessment. Furthermore, the

severity and rate of overexposures to

respirable coal mine dust among the 704

MMUs exhibiting a pattern of recurrent

overexposures are probably also greater

than we have estimated. We have

derived our best estimate of the reduced

risk using the best available data. Yet

due to limitations in the data, we

believe that we have underestimated the

magnitude and frequency of typical

respirable coal mine exposures. To the

extent that our values underestimate the

true reduction in respirable coal mine

dust exposures, we have underestimated

the benefits of these rules.

Other aspects of our risk assessment

methodology reflect more conservative

choices including the selection of an

occupational lifetime of 45-years.

Various factors may affect the

consistency of the type and duration of

jobs miners hold and hence their

associated cumulative exposure levels.

For example, some miners who lose

their jobs upon mine closure are

employed by other mines, sometimes in

less-exposed jobs. Some miners may

chose to move from job to job over their

careers at underground coal mines,

sometimes preferring positions away

from the mining face. Moreover, if the

trend of increasing mechanization

continues, there will be fewer miners,

and for some of them, their occupational

lifetimes will be shorter.

For reasons already explained, we

believe these choices are appropriate for

this risk assessment. We also recognize

that use of the most conservative

approach at every step of the risk

assessment analysis could produce

mathematical risk estimates which,

because of the additive effect of

multiple conservative assumptions, may

overstate the likely risk. We believe this

QRA for simple CWP and PMF strikes

a reasonable balance based on available

data. To the extent that we may have

underestimated the magnitude of

overexposures which would be

prevented, we believe the actual

benefits to be greater than we have

estimated.

It should be noted that reductions in

the prevalence of simple CWP and PMF

attributable to eliminating individual

shift overexposures are not expected to

materialize immediately after the

overexposures have been substantially

reduced or eliminated. Because these

diseases typically arise after many years

of cumulative exposure, allowing for a

period of latency, the beneficial effects

of reducing exposures are expected to

become evident only after a sufficient

time has passed that the reduction in

cumulative exposure could have its

effect. The total realized benefits would

not be fully evident until after the

youngest of today’s underground coal

miners retire.

VIII. Feasibility Issues

Section 101(a)(6)(A) of the Mine Act

(30 U.S.C. 811(a)(6)(A)) requires the

Secretary of Labor to set standards

which most adequately assure, on the

basis of the best available evidence, that

no miner will suffer material

impairment of health or functional

capacity even if such miner has regular

exposure to such hazards dealt with by

42164 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

such standard over his or her working

lifetime. Standards promulgated under

this section must be based upon

research, demonstrations, experiments,

and such other information as may be

appropriate. MSHA, in setting health

standards, is required to achieve the

highest degree of health and safety

protection for the miner, and must

consider the latest available scientific

data in the field, the feasibility of the

standards, and experience gained under

this and other health and safety laws.

In relation to promulgating health

standards, the legislative history of the

Mine Act states that:

* * * This section further provides that

‘‘other considerations’’ in the setting of

health standards are ‘‘the latest available

scientific data in this field, the feasibility of

the standards, and experience gained under

this and other health and safety laws.’’ While

feasibility of the standard may be taken into

consideration with respect to engineering

controls, this factor should have a

substantially less significant role. Thus, the

Secretary may appropriately consider the

state of the engineering art in industry at the

time the standard is promulgated.

* * * * *

Similarly, information on the economic

impact of a health standard which is

provided to the Secretary of Labor at a

hearing or during the public comment

period, may be given weight by the Secretary.

In adopting the language of section

102(a)(5)(A), the Committee wishes to

emphasize that it rejects the view that cost

benefit ratios alone may be the basis for

depriving miners of the health protection

which the law was intended to insure.

S. Rep. No. 95–181, at 21–22 (1977),

reprinted in 1977 U.S.C.C.A.N. 3421–22.

In American Textile Manufacturers’

Institute v. Donovan, 452 U.S. 490, 508–

509 (1981), the Supreme Court defined

the word ‘‘feasible’’ as ‘‘capable of being

done, executed, or effected.’’ The Court

further stated, however, that a standard

would not be considered economically

feasible if an entire industry’s

competitive structure were threatened.

In promulgating standards, hard and

precise predictions from agencies

regarding feasibility are not required.

A. Technological Feasibility

MSHA believes that the plan

verification rule would be

technologically feasible for the mining

industry. An agency must show that

modern technology has at least

conceived some industrial strategies or

devices that are likely to be capable of

meeting the standard, and which

industry is generally capable of

adopting. American Iron and Steel

Institute v. OSHA, (AISI–II) 939 F.2d

975, 980 (D.C. Cir. 1991); American Iron

and Steel Institute v. OSHA, (AISI–I)

577 F.2d 825 (3d Cir. 1978) at 832–835;

and Industrial Union Dep’t., AFL–CIO v.

Hodgson, 499 F.2d 467, 478 (D.C. Cir.

1974).

In designing the plan verification rule,

MSHA has taken into account its

experience and those of the operators to

ensure that the rule provides additional

protection from occupational exposure

to respirable coal mine dust using

current compliance technology (while

encouraging technological

improvements). For this reason, MSHA

believes the proposed plan verification

rule is technologically feasible. MSHA

requires mine operators to utilize all

feasible engineering or environmental

controls, which are specified in the

mine ventilation plan, to maintain

concentrations of respirable dust in the

work environment of MMUs at or below

the applicable dust standard. Mine

operators therefore would not be

required to implement engineering or

environmental controls that were not

technologically feasible.

Based on its vast experience in the

sampling of respirable dust levels in the

MMU work environment, MSHA

believes that technology is currently

available to control respirable dust to

levels at or below the applicable level at

MMUs employing continuous and

conventional methods of mining.

However, MSHA recognizes that, unlike

other mining systems, longwall MMUs

may have acute dust problems caused

by the face-ventilation airstream

carrying the shearer-generated face dust

over the miners working downwind

along the face. In these high-production

longwall MMUs, improvements in dust

control technology have not kept pace

with increases in production

technology. For this reason, the

proposed plan verification rule would

allow longwall operators who have

trouble in meeting MSHA’s respirable

dust standard and who have exhausted

all feasible engineering and

environmental controls to use

administrative controls or loose-fitting

powered air-purifying respirators

(PAPRs), until other feasible controls

become available.

B. Economic Feasibility

The plan verification rule would

clearly be economically feasible for the

underground coal mining industry since

the underground coal mining industry

would derive net compliance cost

savings of approximately $2.04 million

yearly from the proposed plan

verification rule. (Although

implementing the plan verification rule

would cost about $4.75 million yearly,

there would be the following offsetting

yearly savings: $2.19 million from

reduced mine operator citations based

on results from inspector single, fullshift samples and associated abatement

sampling, $1.61 million from reduced

mine operator citations on results from

operators’ bi-monthly samples and

associated abatement sampling, $2.73

million from the elimination of operator

bi-monthly sampling, and $0.27 million

from reduced payouts by mine operators

for Black Lung cases.) Underground coal

mine operators would also obtain a

yearly cost savings of approximately

$0.42 million in reduced penalty costs

associated with the reduction in mine

operator citations arising from the

proposed plan verification rule. The

proposed plan verification rule would

therefore provide a total yearly cost

savings of about $2.46 million to the

underground coal mining industry.

IX. Regulatory Impact Analysis

MSHA’s improved program to

eliminate overexposures on each and

every shift includes (1) the

simultaneous implementation of the use

of inspector single, full-shift respirable

coal mine dust samples to identify

overexposures more effectively in both

underground and surface coal mines

(single, full-shift sample), and (2) in

underground coal mines, verified

ventilation plans to maintain miners’

respirable dust exposure at or below the

applicable standard on each and every

shift (plan verification). The single, fullshift sample NPRM is published

elsewhere in today’s Federal Register.

This part of the preamble reviews

several impact analyses which MSHA is

required to provide in connection with

the proposed plan verification

rulemaking. Since single, full-shift

sample and plan verification are

complementary NPRMs intended to be

promulgated at the same time, the

detailed presentation of assumptions

and estimates for each are available in

the same Preliminary Regulatory

Economic Analysis (PREA)(MSHA,

January 2000).

Assumptions for the requirements of

the plan verification rule are based upon

information provided by MSHA

technical personnel. We encourage the

mining community to provide detailed

comments in this regard to ensure that

plan verification cost assumptions and

estimates are as accurate as possible.

A. Costs and Benefits: Executive Order

12866

In accordance with Executive Order

12866, we have prepared a detailed

PREA of the estimated costs and

benefits associated with the proposed

rule for the underground coal mining

sector. We have fulfilled this

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42165

requirement for the proposed rule and

determined that this rulemaking is not

a significant regulatory action. The key

findings of the PREA are summarized

below.

1. Compliance Costs

The proposed plan verification rule

would provide yearly net compliance

cost savings to underground coal mine

operators of about $2.04 million.

Although implementing the proposed

rule would cost about $4.75 million

yearly, there would be offsetting yearly

savings of: $2.19 million from reduced

mine operator citations issued based on

MSHA inspectors’ single, full-shift

sample results and the elimination of

associated underground operator

abatement sampling; $1.61 million from

reduced mine operator citations issued

based on bi-monthly sampling results

and the elimination of associated

underground operator abatement

sampling; $2.73 million resulting from

underground operators no longer having

to perform bi-monthly operator

sampling; and $0.27 million from

reduced payouts by mine operators for

Black Lung cases.

Table IX–1 summarizes the estimated

net compliance costs by provision for

underground coal mines, for the

following three mine size categories: (1)

those employing fewer than 20 workers;

(2) those employing between 20 and 500

workers; and (3) those employing more

than 500 workers.

In addition to these estimated

compliance costs, mine operators would

derive yearly penalty cost reductions of

about $0.4 million (See Table IX–1(a)).

Penalty costs conventionally are not

considered to be a cost of a rule (and,

in fact, are clearly not a compliance

cost) but merely a transfer payment from

a party violating a rule to the

government. Therefore, the penalty

costs are not included as part of the

compliance costs of the proposed plan

verification rule. These penalty costs are

relevant, however, in determining the

economic feasibility of the proposed

plan verification rule.

The derivation of the above cost

figures are presented in Chapter IV of

the PREA that accompanies this rule.

42166 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

TABLE IX–1.—PV COST

SUMMARY FOR

UNDERGROUND

COAL

MINE

OPERATORS*

Detail

<20 Emp. ≥20 Emp. ≤500 >500 Emp. Total

Adj. first

year costs

Annualized

costs

Annual

costs

Yearly

costs a

Adj. first

year costs

Annualized

costs

Annual

costs

Yearly

costs a

Adj. first

Year costs

Annualized

costs

Annual

costs

Yearly

Costs a

Adj. first

year costs

Annualized

costs

Annual

costs

Yearly

costs a

UNDERGROUND COAL MINES

PV Rule:

Compliance Costs ....................................................... $1,013,905 $70,973 $346,688 $417,661 $7,599,324 $566,960 $3,285,067 $3,852,027 $749,927 $58,653 $420,105 $478,758 $9,363,156 $696,586 $4,051,860 $4,748,446Reduced Inspector Citations b .................................... $234,374 $16,406 ¥$534,712 ¥$518,306 $746,981 $52,289 ¥$1,658,063 ¥$1,605,774 $33,603 $2,352 ¥$71,301 ¥$68,949 $1,014,958 $71,047 ¥$2,264,076 ¥$2,193,029Reduced Operator Citations c ..................................... $106,512 $7,456 ¥$247,790 ¥$240,334 $596,040 $41,723 ¥$1,334,380 ¥$1,292,657 $39,325 $2,753 ¥$76,901 ¥$74,148 $741,877 $51,932 ¥$1,659,071 ¥$1,607,139Eliminate Bi–Mo.—Sampling ...................................... $0 $0 ¥$556,538 ¥$556,530 $0 $0 ¥$2,057,540 ¥$2,057,540 $0 $0 ¥$113,712 ¥$113,712 $0 $0 ¥$2,727,790 ¥$2,727,790Black Lung Savings .................................................... $0 $0 ¥$32,570 ¥$32,570 $0 $0 ¥$217,896 ¥$217,896 $0 $0 ¥$15,196 ¥$15,196 $0 $0 ¥$265,662 ¥$265,662

Net PV Rule ....................................................................... $1,354,791 $94,835 ¥$1,024,922 ¥$930,345 $8,942,345 $660,972 ¥$1,982,812 ¥$1,321,840 $822,855 $63,758 $142,995 $206,753 $11,119,991 $819,565 ¥$2,864,739 ¥$2,045,174

*Data from Preliminary Regulatory Economic Analysis Table IV–16, Table IV–63, Table IV–81, Table IV–100, Table IV–105, and Table IV–106. Note that these costs do not include penalty costs, which are shown in Table IX–1(a) in this document. aYearly costs equals annualized costs plus annual costs.b Reduced costs related to: (1) Reduction in citations issued based on MSHA inspector sample results due to better mine ventilation plans arising from PV rule, and (2) reduction in abatement sampling and associated costs due to elimination of bi-monthly operator sampling. c Reduced costs related to: (1) Reduction in citations issued based on operator sample results due to better mine ventilation plans arising from the PV rule, and (2) reduction in abatement sampling and associated costs due to elimination of operator bi-monthly sampling.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42167

23For details, see Quantitative Risk Assessment

and Significance of Risk sections.

24MSHA estimates an MMU average of 384

production shifts per year. Since miner operators

are required to submit five valid designated

operator (DO samples to MSHA every two months,

there would typically be 30 valid DO samples—for

each MMU that was in operation for the full year.

If dust concentrations on two or more of the

sampled shifts exceed the standard, then it follows,

at a 95-percent confidence level, that the standard

was exceeded on at least six shifts over the full

year.

TABLE IX–1(A).—PV ANNUAL PENALTY COST SUMMARY *

[Yearly penalties]

Detail <20 Emp. ≥20 Emp.

≤500 >500 Emp. Total

Underground Coal Mines

PV Rule:

Reduced Inspector Citations .................................................................... ¥$28,468 ¥$202,334 ¥$5,263 ¥$236,065

Reduced Operator Citations ..................................................................... ¥13,309 ¥160,956 ¥4,960 ¥179,225

Total PV Rule Reduction ................................................................................. ¥41,777 ¥363,290 ¥10,223 ¥415,290

* Data from Preliminary Regulatory Economic Analysis Table IV–16(a), Table IV–82, and Table IV–101.

2. Benefits

Occupational exposure to excessive

levels of respirable coal mine dust

imposes significant health risks. These

include the following adverse health

outcomes: simple coal worker’s

pneumoconiosis (simple CWP),

progressive massive fibrosis (PMF),

silicosis, and chronic obstructive

pulmonary disease (COPD) (e.g., asthma,

chronic bronchitis, emphysema) (See

the Health Effects section for details).

Cumulative exposure to respirable coal

mine dust is the main determinant in

the development of both simple CWP

and PMF although other factors such as

the percentage of quartz in the

respirable dust and the type of coal also

affect the risk of miners developing

simple CWP and PMF (Jacobsen, et al.,

1977; Hurley, et al., 1987; Kuempel, et

al., 1995; Attfield and Morring, 1992;

Attfield and Seixas, 1995). The true

magnitude of occupationally induced

simple CWP and PMF among today’s

coal miners is unknown, although

prevalence estimates are available from

various surveillance systems. For

example, from 1970 to 1995, the

prevalence of simple CWP and PMF

among miners, based on the operator

sponsored x-ray program, dropped from

11 percent to 3 percent (MSHA, Internal

Chart, 1998). Also, later rounds of the

National Study for Coal Worker’s

Pneumoconiosis consistently

demonstrated, through prevalence rates

in the range of 2.9—3.9 percent, that

simple CWP and PMF have not been

eliminated.

Through the joint promulgation of

single, full-shift sample and plan

verification rules, miners would be

further protected from the debilitating

effects of occupational respiratory

disease by limiting their exposures to

respirable coal mine dust to no more

than the applicable standard on each

and every shift.23 Reducing respirable

coal mine dust concentrations over a 45-

year occupational lifetime to no more

than the applicable standard on just that

percentage of shifts showing an excess

would lower the cumulative exposure,

thereby significantly reducing the risk of

both simple CWP and PMF among

miners. We have estimated the health

benefits of the two rules arising from the

elimination of overexposures on all

shifts at only those MMUs exhibiting a

pattern of recurrent overexposures on

individual shifts.

Based on 1999 operator data, there

were 704 MMUs (out of 1,251) at which

regular (not abatement) designated

occupational (DO) samples exceeded the

applicable standard on at least two of

the sampling shifts reported in 1999

(MSHA, Data file:Operator.ZIP). MSHA

considers these 704 MMUs, representing

more than one-half of all underground

coal miners working in production

areas, to have exhibited a pattern of

recurrent overexposures. Based on valid

DO operator samples were collected on

a total of 18,569 shifts at these 704

MMUs; the applicable standard was

exceeded on 3,977 of these shifts or 21.4

percent.

At the MMUs being considered (those

exhibiting a pattern of recurrent

overexposures),24 bringing dust

concentrations down to no more than

the applicable standard on each and

every production shift would reduce DO

exposures on the affected shifts by an

average of 1.04 mg/m3. Assuming this

average reduction applies to only 21

percent of the shifts, the effect would be

to reduce cumulative exposure, for each

miner exposed at or above the DO level,

by 0.22 mg-yr/m3 over the course of a

working year (i.e., 21 percent of shifts in

one year times 1.04 mg/m3 per shift).

Therefore, over a 45-year working

lifetime, the benefit to each affected DO

miner would, on average, amount to a

reduction in accumulated exposure of

approximately 10 mg-yr/m3 (i.e., 45

years times 0.22 mg-yr/m3 per year). If,

as some miners have testified, operator

dust samples submitted to MSHA tend

to under-represent either the frequency

or magnitude (or both) of individual

full-shift excursions above the

applicable standard, then eliminating

such excursions would provide a

lifetime reduction of even more than 10

mg-yr/m3 for each exposed miner.

When the dust concentration

measured for the DO exceeds the

applicable standard, measurements for

at least some of the other miners

working in the same MMU may also

exceed the standard on the same shift,

though usually by a smaller amount.

Furthermore, although the DO

represents the occupation most likely to

receive the highest exposure, other

miners working in the same MMU may

be exposed to even higher

concentrations than the DO on some

shifts. Therefore, in addition to the

affected DO miners, there is a

population of other affected miners who

are also expected to experience a

significant reduction in risk as a result

of eliminating overexposures on their

individual shifts.

To estimate how many miners other

than the DO would be substantially

affected, MSHA examined the results

from all valid dust samples collected by

MSHA inspectors in underground

MMUs during 1999 (MSHA, Data file:

Inspctor.zip). Within each MMU, the

inspector typically takes one full-shift

sample on the DO and, on the same

shift, four or more additional samples

representing other occupations. On 896

shifts, at a total of 450 distinct MMUs,

the DO measurement exceeded the

applicable standard and there were at

least three valid measurements for other

occupations available for comparison.

There was an average of 1.2 non-DO

42168 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

25With 95-percent confidence, on shifts for which

the DO measurement exceeds the standard, the

mean number of other occupational measurements

also exceeding the standard is at least 1.11.

26With 95-percent confidence, the mean excess is

at least 0.72 mg/m 3.

27Since females have a greater life expectancy

than males, the expected benefits would increase if

the proportion of female miners were to increase

substantially in the future.

28 If a different definition of ‘‘exhibiting a

recurrent pattern of overexposures’’ were used in

these analyses, the estimate of the reduction in risk

and associated benefits would be different. For

example, if the criterion were that four or more DO

bimonthly exposure measurements exceeded the

applicable standard, we could state, with 95%

confidence, that the standard was exceeded on at

least 20 shifts in a year of 384 shifts. Using four as

the criterion would reduce the population for

whom we are estimating benefits, and decrease the

estimated number of prevented cases by 19%.

29Nine hundred and eighty-four refers to the

number of MMUs operating on February 12, 1999.

The 1,443 number mentioned previously refers to

all MMUs in operation at any time in 1999.

measurements in excess of the standard

on shifts for which the DO measurement

exceeded the standard.25 For non-DO

measurements that exceeded the

standard on the same shift as a DO

measurement, the mean excess above

the standard was approximately (0.8

mg/m3).26

Combining these results with the 21-

percent rate of excessive exposures

observed for the DO on individual

shifts, it is reasonable to infer that, at

the MMUs under consideration, an

average of 1.2 other miners, in addition

to the one classified as DO, is

overexposed on at least 21 percent of all

production shifts. Over the course of a

working year, the reduction in exposure

expected for these affected nondesignated occupational (NDO) miners,

is 0.17 mg-yr/m3 (i.e., 21 percent of one

year, times 0.8 mg/m3).

The expected lifetime for all

American males, conditional on their

having reached 20 years of age, is 73

years (U.S. Census March 1997, Table

18; U.S. Census March 1997, Table

119).27 On average, the best estimate of

the lifetime benefit to exposed miners is

expressed by the reduction in

prevalence of disease at age 73. To

project the reduction in risk of simple

CWP and PMF among affected DOs and

NDOs, MSHA applied its best estimate

of dose response to a hypothetical

cohort of underground coal miners who

work on an MMU exhibiting a pattern

of recurrent overexposure, and who, on

average, begin working at age 20, retire

at age 65, and live to age 73.28 Strengths

and weaknesses of various

epidemiological studies were presented

in the Health Effects section supporting

the selection of Attfield and Seixas

(1995) as the study that provides the

best available estimate of material

impairment with respect to simple CWP

and PMF. Two of the distinguishing

qualities of Attfield and Seixas (1995)

are the dose-response relationship over

a miner’s lifetime and the fact that these

data best represent the recent conditions

experienced by miners in the U.S. Using

this relationship, it is possible to

evaluate the impact on risk of both

simple CWP and PMF expected from

bringing respirable coal mine dust

concentrations down to or below the

applicable standard on every shift. This

is the only contemporary

epidemiological study of simple CWP

and PMF providing such a relationship.

To estimate the benefits (i.e., number

of cases of simple CWP and PMF

prevented) of single, full-shift sample

and plan verification combined, we

applied these estimates of risk reduction

to the estimated sub-populations of

affected miners. As of February 12,

1999, there were 984 producing

MMUs;29 applying the pattern of

recurrent overexposures among MMUs

as identified in the Quantitative Risk

Assessment, 56 percent, by mine size,

we estimate there to be 552 affected

MMUs (MSHA Table, November 18,

1999; MSHA Table, February 12, 1999).

Based on MSHA’s experience, we would

expect one DO and seven NDOs for each

shift of production at each MMU.

Therefore, among underground coal

miners working on an MMU, we

estimate 12.5% to be designated

occupational miners and 87.5% to be

non-designated occupational miners.

The benefits that will accrue to coal

miners exposed to respirable coal mine

dust and to mine operators, and

ultimately to society at large, are

substantial and take a number of forms.

These proposed rules would reduce a

significant health risk to underground

coal miners, reducing the potential for

illnesses and premature death and their

attendant costs to miners, their

employers, their families, and society.

The joint promulgation of these rules

should realize a positive economic

impact on the Department of Labor’s

(DOL’s) Black Lung Program and

relatedly on mine operators. The Black

Lung Program compensates eligible

miners, and their survivors under the

Black Lung Benefits Act. This program

provides monthly payments and

medical benefits (diagnostic and

treatment) to miners who are found to

be totally disabled by black lung

disease, including cases of PMF and

simple CWP. In 1986, DOL’s

Employment Standards Administration

reported that 12% of approved cases of

Black Lung Program were identified as

cases of PMF based on chest

radiographs, while sixty-four percent

had simple CWP based on chest

radiographs. For miners who stopped

working in coal mines after 1969 and for

whom the DOL can establish that the

miner worked for the same operator for

at least one calendar year, and that

miner had at least 125 working days in

that year, that operator is financially

responsible for the miner’s Black Lung

benefit payment. If a responsible

operator cannot be identified for an

eligible miner, benefit payments are

made by the Black Lung Disability Trust

Fund. To the extent that these rules

reduce overexposures to respirable coal

mine dust, there should be fewer Black

Lung Program cases. Therefore, over

time, the associated financial outlay by

responsible operators through either

insurance premiums or direct payments

of Black Lung benefits should be lower

than would otherwise occur. The

financial impact could be substantial

see discussion in Chapter IV, of the

PREA. In 1980, the Black Lung Program

estimated average lifetime pay-outs for

responsible operators for married

miners of about $248,700 dollars,

assuming a 7 percent annual rate

increase (ESA, 1980). In fiscal year

1999, 443 claims for Black Lung

Benefits were accepted as new cases;

sixty-six percent (293) are the financial

responsibility of coal mine operators

(Peed, 2000).

Table IX–2 presents the estimated

number of cases of simple CWP and

PMF that would be prevented among

the 56 percent of MMUs exhibiting a

pattern of recurrent overexposures. For

all categories of simple CWP and PMF

combined, we estimate 37 fewer of these

cases, among affected miners, than

would otherwise occur without the

promulgation of single, full-shift sample

and plan verification rules. Eleven of

these cases would be the most severe

form of coal miners pneumoconiosis,

PMF, and as such this benefit could be

interpreted as prevented premature

deaths due to occupational exposure to

respirable coal mine dust. Since simple

CWP predisposes the development of

PMF, it is important that it also be

prevented (Balaan, et al., 1993).

As discussed in the Significance of

Risk sections, MSHA believes this QRA

for simple CWP and PMF strikes a

reasonable balance based on available

data. Yet, our estimates likely

understate the true impact of these rules

since our analyses are restricted to a

sub-population of affected miners, those

working at MMUs exhibiting a pattern

of recurrent overexposures, not the

broader population of coal miners who

will benefit from these rules.

Furthermore, to estimate the average

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42169

30Applying an estimated prevalence rate of 3.0

percent to the estimated population of affected

miners (8,640) results in an estimate of 259 cases

of simple CWP and PMF.

overexposure which would be

prevented, MSHA had to use data

collected for compliance purposes

which may not represent typical

environmental conditions.

The degree to which the exposure

level of respirable coal mine dust on

sampling shifts may not be

representative of typical exposure levels

is affected by the following factors:

(1) There exists a positive relationship

between coal production and generation

of respirable coal mine dust;

(2) Current sampling procedures

permit sampling measurements to be

taken at the mid-range of the

distribution of level of production—

sampling measurements must be taken

on shifts with production at least 60%

of the average production during the last

30 days and at least 50% of average

production for the last valid set of

bimonthly samples for inspector and

operator samples, respectively;

(3) Miners have reported and MSHA

data have demonstrated lower levels of

production on sampling shifts versus

non-sampling shifts (MSHA, September

1993);

(4) On some sampling shifts, miners

have reported that more engineering

controls may be used than on other

shifts, thus reducing the measured

amount of respirable coal mine dust;

(5) MSHA analyses have

demonstrated, even when controlling

for production, in mines with fewer

than 125 employees, on continuous

mining MMUs, respirable coal mine

dust exposures were much higher

during the unannounced Spot

Inspection Program (SIP) sampling

shifts than on shifts operators

sampled—this is consistent with the

effect of increasing engineering controls

on shifts during which bimonthly

samples are conducted compared to the

level of use of engineering controls used

on shifts for which the operator does not

expect sampling to be conducted given

the same production level (Denk, 1993);

(6) Across mine size, designated area

samples have been found to be larger for

shifts on which unannounced

compliance sampling occurred

compared to operator sampling shifts—

in one study they differed by at least a

factor of 40 percent in large mines and

100 percent in the smallest mines (ibid.

p 211–212); and

(7) Existing MSHA technical

information indicates that some

reduction in production levels occurs

during some sampling periods on

longwalls (Denk, 1990).

Therefore, at a bare minimum, over an

occupational lifetime (45-years) for

miners who live to age 73 who worked

at MMUs exhibiting a pattern of

recurrent overexposures, we estimate at

least 37 fewer cases of pneumoconiosis

(simple coal workers pneumoconiosis

(CWP) and progressive massive fibrosis

(PMF)) than would otherwise occur

without the promulgation of these rules.

Our current quantitative estimate of

benefits demonstrates and qualitative

discussions punctuate that these rules

will have a significant positive impact

on the health of our Nation’s coal

miners when promulgated. Yet, due to

the limitations on these data, we believe

our benefit estimate may understate the

number of cases of simple CWP and

PMF which would be prevented over an

occupational lifetime.

MSHA believes that cases of simple

CWP and PMF would also be prevented

among other types of underground

miners, such as roofbolters working in

designated areas (DA). Based on MSHA

experience it is reasonable to expect

roofbolter DA’s pattern of overexposures

for respirable coal mine dust to be

similar to that for miners with the

highest exposure on an MMU. If so, we

would expect 13 additional cases of

simple CWP and PMF to be prevented.

Affected DAs include DAs who work at

the 56 percent of the MMUs under

consideration who are exposed to dust

concentrations similar to the DO, over a

45-year occupational lifetime (MSHA

Table, November 18, 1999; MSHA

Table, February 12, 1999).

Although the effect cannot readily be

quantified, to the extent that these rules

would also reduce the cumulative

exposure to respirable coal mine dust

among some miners working in those

MMUs not exhibiting overexposures, it

is reasonable to expect that we would

observe an incremental benefit among

that sub-population of coal miners.

Moreover, to the extent that the

cumulative dust exposure is reduced for

miners working in the ‘‘out by’’ areas,

away from the mining face (i.e., MMU)

where coal is extracted from the coal

seam, they too may realize occupational

health benefits due to the simultaneous

promulgation of these proposals.

Therefore, our best estimate of 37

prevented cases of simple CWP and

PMF, combined, among all affected

miners likely underestimates the true

benefit realized by the coal mining

workforce through the reduction of

overexposures to no more than the

applicable standard on each shift.

Clearly PMF is associated with

premature death. Since simple CWP

may evolve to PMF, even after

occupational exposure has ceased, it has

the propensity to become a life

threatening illness. By reducing the total

number of simple CWP and PMF cases

among affected miners from 259 to 222,

over 45 years, these standards, at a

minimum, are projected to prevent an

average of four cases of simple CWP and

PMF for each 5-year interval.30

For all those reasons previously

identified, MSHA believes that its

estimate of 37 prevented cases of simple

CWP and PMF over a 45 year working

life understates the true number of cases

of simple CWP and PMF which would

be prevented. This belief is further

supported by the fact that during the

past few years, the Black Lung Benefits

Program has been approving roughly

400 claims each year. These claims

come from individuals whose exposure

for the most part came after the current

standard of 2.0 was established in 1972.

Thus, we believe the consistent annual

approval by the Black Lung Benefits

Program, of hundreds of new cases of

simple CWP and PMF per year, supports

our belief that the true lifetime

occupational health benefits of the

proposed rules are higher than we have

estimated. Even assuming that the

number of new claims would decline in

future years simply due to the

continuing decline in the number of

coal miners, MSHA expects that

assuring that future exposures are

maintained below the 2.0 exposure limit

will reduce the number of new cases of

simple CWP and PMF by considerably

more than 1 per year.

In addition to the prevention of

simple CWP and PMF, each of the 8,640

affected miners at MMUs exhibiting a

pattern of recurrent overexposures will

realize some health benefit by limiting

his or her cumulative exposure to

respirable coal mine dust to no more

than the applicable standard on each

and every shift.

The expected number of prevented

cases of simple CWP and PMF would

not be realized for some time even after

the pattern of overexposures has been

minimized or eliminated. This is due, in

part, to the latency—that is, the disease

does not develop immediately after

exposure—of the development of simple

CWP and PMF and the pre-existing

occupational exposure histories of

members of the current coal mining

workforce. Our estimated benefit is

based on the estimated number of

underground coal miners working at the

mine face, 17,280. If the size of this

workforce significantly changed in the

future and the projected pattern of

prevented overexposures remained the

same, the number of cases of prevented

42170 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

simple CWP and PMF would need to be

adjusted to account for the change.

Various data, assumptions and

caveats were used to conduct the

quantitative risk assessment,

significance of risk discussion, and

benefits analyses. Therefore, we request

any information which would enable us

to conduct more accurate analyses of the

estimated health benefits of the single,

full-shift sample rule and plan

verification rule, both individually, and

in combination.

TABLE IX–2.—OVER A WORKING LIFETIME AMONG AFFECTED MINERS, ESTIMATED NUMBER OF CASES OF CWP A AND

PMF B PREVENTED DUE TO THE IMPLEMENTATION OF SINGLE, FULL-SHIFT SAMPLE AND PLAN VERIFICATION

Type of Miner

Affected

Miners,

n=

Simple CWP categories

1, 2, 3 or PMF

Simple CWP categories

2 or 3 or PMF

PMF

Reduction

in risk c

Prevented

cases,

n=

Reduction

in risk c

Prevented

cases,

n=

Reduction

in risk c

Prevented

Cases,

n=

Affected Designated Occupational Miners d .......... 1,080 18/1000 19.4 9.8/1000 10.6 5.1/1000 5.5

Affected Non-Designated Occupational Miners e .. 7,560 2.3/1000 17.4 1.3/1000 9.8 0.7/1000 5.3

Total ......................................................... 8,640 NA 37 NA 20 NA 11

aSimple CWP: Simple coal workers’ pneumoconiosis.

bPMF: Progressive massive fibrosis.

c Reduction in risk per 1,000 affected miners, over a 45-year working lifetime.

dAffected Designated Occupation (DO) Miners: Includes all miners who work at the 56-percent of the Mechanized Mining Units under consideration and who are exposed to dust concentrations similar to the DO, over a 45-year occupational lifetime. eAffected Non-Designated Occupation (Non-DO) Miners: Includes all underground faceworkers under consideration who are not classified as

the DO.

B. Regulatory Flexibility Certification

and Initial Regulatory Flexibility

Analysis

The Regulatory Flexibility Act

requires MSHA to conduct an analysis

of the effects of the proposed plan

verification rule on small entities. That

analysis is summarized here; a copy of

the full analysis is included in Chapter

V of our PREA in support of the

proposed single, full-shift sample and

plan verification rules. We encourage

the mining community to provide

comments on this analysis.

The Small Business Administration

generally considers a small entity in the

mining industry to be one with 500 or

fewer workers. MSHA has traditionally

defined a small mine to be one with

fewer than 20 workers, and has focused

special attention on the problems

experienced by such mines in

implementing safety and health rules.

Accordingly, we have separately

analyzed the impact of the joint notice

proposed rule both on mines with 500

or fewer workers and on those with

fewer than 20 workers.

Pursuant to the Regulatory Flexibility

Act, MSHA must determine whether the

costs of the joint notice proposed rule

constitute a ‘‘significant impact on a

substantial number of small entities.’’

Pursuant to the Regulatory Flexibility

Act, if an Agency determines that a

proposed rule would not have such an

impact, it must publish a ‘‘certification’’

to that effect. In such a case, no

additional analysis is required (5 U.S.C.

§ 605). In evaluating whether

certification is appropriate, MSHA

utilized a ‘‘screening test,’’ comparing

the costs of the proposed plan

verification rule to the revenues of the

affected coal sector. If the estimated

costs are less than 1 percent of revenues

for the affected entities, or they are

negative (that is, they provide a cost

savings), then the rule is assumed not to

have a significant impact on small mine

operators.

Table IX–3 compares, for small

underground coal mines (using both

MSHA’s and SBA’s definition), MSHA’s

estimated total annual compliance costs

of the proposed plan verification rule to

estimated annual revenues.

Table IX–3 shows that under either

MSHA’s or SBA’s definition of a small

mine, the proposed plan verification

rule would provide a net cost savings to

small underground coal mines. As a

result, MSHA is certifying that the

proposed plan verification rule for

underground coal mines would not have

a ‘‘significant impact on a substantial

number of small entities,’’ and has

performed no further analyses.

TABLE IX–3.—ESTIMATED YEARLY COSTS OF PROPOSED PLAN VERIFICATION RULE RELATIVE TO YEARLY REVENUES FOR

UNDERGROUND COAL MINES

[Dollars in thousands]

Mine size

Proposed

rule

net costs a

Underground

coal mine

revenues b

Costs as

percentage of

revenues

< 20 employees ........................................................................................................................... ($930.1) $249,418 (0.4%)

< 500 employees c ....................................................................................................................... ($1,251.9) $6,883,339 (0.03%)

aEstimated yearly costs are composed of ‘‘adjusted’’ first year costs that have been annualized plus annual costs.

b Data for revenues derived from: U.S. Department of Labor, Mine Safety and Health Administration, Office of Standards, Regulations, and

Variances, based on 1997 Final MIS data (quarter 1–quarter 4), CM441, cycle 1997/184; and U.S. Department of Energy, Energy Information

Administration, Annual Energy Review 1998, DOE/EIA–0384(98), July 1999, p 203. c Includes mines with fewer than 20 employees.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42171

31A hypothetical example might help to explain

this procedure. Suppose that compliance costs are

$2,000 the first year and $400 each year thereafter.

The adjustment procedure simply splits first year

compliance costs into two parts: (1) $400, for the

first year of annual costs; and (2) the residual

$1,600. Consequently, adjusted first year costs

would be $1,600 and annual costs (starting in year

1) would be $400.

X. Other Statutory Requirements

A. Plain Language

We (MSHA) wrote appropriate

portions of this proposed rule in the

more personal style advocated by the

President’s Memorandum on ‘‘plain

language.’’ ‘‘Plain language’’ encourages

the use of personal pronouns (we and

you); sentences in the active voice; a

greater use of headings, lists, and

questions, as well as charts, figures, and

tables.

In this proposed rule, ‘‘you’’ refers to

production-operators and independent

contractors because they have the

primary responsibility for compliance

with MSHA regulations. In addition, we

recognize and appreciate the value of

comments, ideas, and suggestions from

labor organizations, industry

associations, and other parties who have

an interest in health and safety training

for miners.

We would appreciate comments and

suggestions from all parties on this

proposed rule and on our use of ‘‘plain

language.’’ How could we improve the

clarity of this style?

B. Unfunded Mandates Reform Act of

1995

For purposes of the Unfunded

Mandates Reform Act of 1995, this rule

does not include any Federal mandate

that may result in increased

expenditures by State, local, and tribal

governments, or increased expenditures

by the private sector of more than $100

million.

C. Paperwork Reduction Act of 1995

The proposed plan verification rule

contains information collections which

are subject to review by the Office of

Management and Budget (OMB) under

the Paperwork Reduction Act of 1995

(PRA95). The proposed rule has first

year burden hours (those that occur only

in the first year) and, annual burden

hours which occur in the first year and

every year thereafter.

How some types of burden hours and

costs were handled requires

explanation. In a few cases, the

proposed plan verification rule imposes

burden hours and costs that would be

the same every year, beginning with the

first year that the rule takes effect. These

are ‘‘annual’’ burden hours and costs, as

traditionally defined.

In most cases, however, the proposed

plan verification rule imposes burden

hours and costs which would be the

same each year starting with the second

year the proposed rule is in effect, but

whose first year burden hours and costs

would be different. MSHA transformed

these first year burden hours and costs

and annual burden hours and costs

starting in Year 2 into adjusted first year

burden hours and costs (first year

burden hours and costs minus an

amount equal to annual burden hours

and costs starting with Year 2 after the

rule takes effect) and true annual burden

hours and costs starting in Year 1 after

the rule takes effect.31

First Year Burden Hours

In the first year the plan verification

rule is in effect, there would be a total

net burden hour savings, for

underground coal mine operators, of

44,750, which is composed of 7,912 first

year burden hours (from Table X–1) and

52,662 annual burden hour savings

(from Table X–2). The 44,750 net

burden hour savings have associated

cost savings of $847,236, which is

composed of $360,820 of adjusted first

year costs (from Table X–1) and

$1,208,056 of annual cost savings (from

Table X–2).

Annual Burden Hours in Second Year

and Every Year Thereafter

There would be a total net annual

burden hour savings, for underground

coal mine operators, in the second year

the proposed plan verification rule is in

effect and every year thereafter of

52,662, which has associated cost

savings of approximately $1.21 million

annually (from Table X–2). These net

burden hours and costs include annual

burden hour and cost savings due to:

reduced mine operator citations based

on MSHA inspectors’ single, full-shift

sample results and the elimination of

associated operator abatement sampling;

reduced mine operator citations issued

based on bi-monthly sampling results

and the elimination of associated

operator abatement sampling; and

savings from operators no longer having

to perform bi-monthly operator

sampling.

TABLE X–1.—SUMMARY OF PV PROPOSED

RULE

FIRST

YEAR

PAPERWORK

BURDEN

HOURS AND

RELATED

COSTS

THAT

OCCUR

Detail

<20 emp. ≥20 emp. ≤500 >500 emp. 

Adjustedfirst year

hours

Adjustedfirst year

costs

Adjustedfirst year

costs

annualized

Adjustedfirst year

hours

Adjustedfirst year

costs

Adjustedfirst year

costs

annualized

Adusted first

year hours

Adjustedfirst year

costs

Adjustedfirst year

costs

annualized

UNDERGROUND COAL MINES

PV Rule:

Increase ................................................................................................ 1,359 $61,059 $4,274 6,140 $280,581 $20,372 398 $18,425 $1,399 Reduced Inspector Citations a ............................................................... 3 $151 $11 6 $302 $21 0 $0 $0 Reducted Operator citations b ............................................................... 3 $151 $11 3 $151 $11 0 $0 0 Elimination of Bi-Mo. Sampling ............................................................. 0 $0 $0 0 $0 $0 0 $0 $0 

Net PV Rule ................................................................................................. 1,365 $61,361 $4,296 6,149 $281,034 $20,404 398 $18,425 $1,399 

* Source: Preliminary Regulatory Economic Analysis Tables VII-32, VII-43, and VII-53.a Related to reduced citations issued based on inspector sample results due to better mine ventilation plans arising from the PV rule. b Related to reduced citations issued based on operator sample results due to better mine ventilation plans arising from the PV rule.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42173

TABLE X–2.—SUMMARY OF ANNUAL PAPERWORK BURDEN HOURS AND RELATED COSTS THAT OCCUR IN THE FIRST YEAR

AND EVERY YEAR THEREAFTER *

Detail

<20 emp. ≥20 emp. ≤500 >500 emp. Total

Annual

hours

Annual

costs

Annual

hours

Annual

costs

Annual

hours

Annual

costs

Annual

hours Annual costs

UNDERGROUND COAL MINES

PV Rule:

Increase ................ 315 $14,126 1,458 $63,236 111 $4,550 1,884 $81,912

Reduced Inspector

Citations a .......... ¥1,012 ¥$24,678 ¥2,941 ¥$71,911 ¥111 ¥$2,695 ¥4,064 ¥$99,285

Reduced Operator

Citations b .......... ¥474 ¥$11,606 ¥2,394 ¥$58,386 ¥105 ¥$2,561 ¥2,973 ¥$72,553

Elimination of BiMo. Sampling .... ¥9,084 ¥$212,901 ¥35,350 ¥$830,435 ¥3,075 ¥$74,794 ¥47,509 ¥$1,118,130

Net PV Rule ................. ¥10,255 ¥$235,059 ¥39,227 ¥$897,496 ¥3,180 ¥$75,500 ¥52,662 ¥$1,208,056

*Source: Preliminary Regulatory Economic Analysis Tables VII–7, VII–33, VII–43, VII–53, and VII–57.

a Reduction related to: (1) Reduced citations issued based on inspector sample results due to better mine ventilation plans arising from the PV

rule and (2) reduced abatement sampling and associated costs due to the elimination of bi-monthly operator sampling. b Reduction related to: (1) Reduced citations issued based on operator sample results due to better mine ventilation plans arising from the PV

rule and (2) reduced abatement sampling and associated costs due to the elimination of bi-monthly operator sampling.

We invite public comments and are

particularly interested in comments

which:

1. Evaluate whether the proposed

collection of information (presented

here and in the PREA for the proposed

single, full-shift sample and plan

verification rules) is necessary for the

proper performance of the functions of

MSHA, including whether the

information will have practical utility;

2. Evaluate the accuracy of our

estimate of the burden of the proposed

collection of information, including the

validity of the methodology and

assumptions used;

3. Enhance the quality, utility, and

clarity of the information to be

collected; and

4. Minimize the burden of the

collection of information on

respondents, including through the use

of appropriate automated, electronic,

mechanical, or other technological

collection techniques or other forms of

information technology, e.g., permitting

electronic submissions of responses.

We have submitted a copy of this

proposed rule to OMB for its review and

approval of these information

collections. Interested persons are

requested to send comments regarding

this information collection, including

suggestions for reducing this burden, to

the Office of Information and Regulatory

Affairs, OMB New Executive Office

Building, 725 17th St., NW, Rm. 10235,

Washington, DC 20503, Attn: Desk

Officer for MSHA. Submit written

comments on the information collection

not later than September 5, 2000.

Our paperwork submission

summarized above is explained in detail

in the PREA. The PREA includes the

estimated costs and assumptions for

each proposed paperwork requirement

related to this proposed rule. A copy of

the PREA is available from us. These

paperwork requirements have been

submitted to the Office of Management

and Budget for review under section

3504(h) of the Paperwork Reduction Act

of 1995. Respondents are not required to

respond to any collection of information

unless it displays a current valid OMB

control number.

D. National Environmental Protection

Act

The National Environmental Policy

Act (NEPA) of 1969 requires each

Federal agency to consider the

environmental effects of proposed

actions and to prepare an

Environmental Impact Statement on

major actions significantly affecting the

quality of the human environment. We

have reviewed the proposed standard in

accordance with the requirements of the

NEPA (42 U.S.C. 4321 et seq.), the

regulation of the Council on

Environmental Quality (40 CFR part

1500), and the Department of Labor’s

NEPA procedures (29 CFR part 11). As

a result of this review, we have

preliminarily determined that this

proposed standard will have no

significant environmental impact.

Commenters are encouraged to submit

their comments on this determination.

E. Executive Order 12630

(Governmental Actions and Interference

with Constitutionally Protected Property

Rights)

This proposed rule is not subject to

Executive Order 12630, Governmental

Actions and Interference with

Constitutionally Protected Property

Rights, because it does not involve

implementation of a policy with takings

implications.

F. Executive Order 12988 (Civil Justice)

The Agency has reviewed Executive

Order 12988, Civil Justice Reform, and

determined that this rulemaking will

not unduly burden the Federal court

system. The regulation has been written

so as to provide a clear legal standard

for affected conduct, and has been

reviewed carefully to eliminate drafting

errors and ambiguities.

G. Executive Order 13045: Protection of

Children from Environmental Health

Risks and Safety Risks

In accordance with Executive Order

13045, protection of children from

environmental health risks and safety

risks, we have evaluated the

environmental health or safety effects of

the proposed rule on children. The

Agency has determined that this

proposal would not have an adverse

impact on children.

H. Executive Order 13084 (Consultation

and Coordination With Indian Tribal

Governments)

We certify that this proposed rule

does not impose substantial direct

compliance costs on Indian tribal

governments.

I. Executive Order 13132 (Federalism)

We have reviewed this rule in

accordance with Executive Order 13132

regarding federalism, and have

determined that it does not have

‘‘federalism implications.’’ The rule

does not ‘‘have substantial direct effects

on the States, on the relationship

between the national government and

the States, or on the distribution of

42174 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

1 In some publications, this ratio is called the

relative standard deviation (RSD). It is sometimes

also denoted by CVtotal, where ‘‘total’’ refers to all

sources of potential sampling and analytical error

but does not cover variability in μ itself.

power and responsibilities among the

various levels of government.’’

XI. Public Hearings

MSHA plans to hold public hearings

on the proposed rule. The hearings will

be held in Prestonsburg, Kentucky

(Jenny Wiley, State Resort Park);

Morgantown, West Virginia; and Salt

Lake City, Utah. The hearing dates,

times, and specific locations will be

announced by a separate document in

the Federal Register. The hearings will

be held under Section 101 of the Federal

Mine Safety and Health Act of 1977.

Appendix A—Derivation of the Critical

Values

All measurements of respirable dust

concentration are subject to potential

sampling and analytical errors. Because of

such errors, a measurement may fall slightly

below the verification limit even when the

true concentration of respirable coal mine

dust or crystalline silica does not. Therefore,

to ensure that the verification limits have

actually been met, it is necessary to provide

for a margin of error in each measurement.

The critical values provide this margin of

error. When valid measurements do not

exceed the appropriate critical values, we can

be confident that the verification limits have

not been exceeded at the sampled locations.

To explain how the verification limits were

derived, it is helpful to define some symbolic

notation. Let X represent a measurement, and

let μ represent the true value of whatever

quantity is being measured—i.e., the full shift

average concentration, at a specific sampling

location, of either respirable coal mine dust

or respirable crystalline silica dust. The

difference between X and μ is the

measurement error and is denoted by ε. X =

μ + ε.

In accordance with standard statistical and

industrial hygiene practice, ε (but not μ) is

assumed to be normally distributed. Since

the approved sampling and analytical

methods for measuring concentrations of

respirable coal mine dust and respirable

silica dust are both statistically unbiased, ε

has a mean value of zero and a degree of

variability represented by its standard

deviation, denoted by σε. The ratio of σε to

μ is called the measurement coefficient of

variation (CV) due to sampling and analytical

errors.1 The CV relates entirely to variability

due to measurement errors and not at all to

variability in actual dust concentrations.

For respirable coal mine dust, the value of

CV used in calculating critical values was

chosen to be consistent with the value

proposed at μ = 2.0 mg/m3 in the Coal Mine

Respirable Dust Standard Noncompliance

Determinations Notice, (63 FR 5700,

February 3, 1998):

CV = ++ = ((( 7%) 5%) 5%) 10% 222

The 7-percent term in this formula accounts

for uncertainty due to potential weighing

error, and the two 5-percent terms account

for differences between individual cyclones

and for variability in the exact volume of air

pumped through the filter during a 480-

minute shift.

For respirable silica dust, the value of CV

used in calculating critical values is:

CV = ++ = (. (. (. 5 3%) 4 2%) 5 6%) 9% 222

The 5.3-percent term in this formula

accounts for imprecision in the Infrared

(Infrared Spectrophotometer or IR)

measurement of crystalline silica mass

deposited on the filter, the 4.2-percent term

represents variability in air volume, and the

final 5.6-percent term accounts for

uncertainty due to variability between

individual cyclones, given the size

distribution of crystalline silica dust

encountered in mining environments

(Bartley, November 1999).

Each critical value (c) was calculated to

provide a confidence level of at least 95

percent that the ventilation plan was

effective in preventing dust concentrations

from exceeding the verification limits. Using

a confidence coefficient of 1.645, based on

the standard normal probability distribution,

knowledge of the CV makes it possible to

calculate a 1-tailed, 95-percent upper

confidence limit (UCL) for μ, given a single

measurement X. The UCL is X·(1 + 1.645·CV).

When X ≤ c, the UCL for μ is less than or

equal to the verification limit. When X > c,

the UCL for μ exceeds the verification limit.

For example, suppose X = 1.71 mg/m3

respirable dust. Then the UCL for μ would be

1.71·(1 + (10% of 1.645)) = 1.99 mg/m3,

which is less than the verification limit for

respirable coal mine dust. If, however, X =

1.72 mg/m3, then the UCL for μ would be

1.72·1.1645 mg/m3, which slightly exceeds

the verification limit. Similarly, for respirable

crystalline silica dust, the UCL for μ is 87·(1

+ (9% of 1.645)) = 99.9 μg/m3 when X = 87

μg/m3 and slightly above the verification

limit of 100 μg/m3 when X = 88 μg/m3.

If more than one measurement is available,

then the confidence coefficient changes to

reflect multiplication of the tail probabilities

for independent measurement errors. When n

measurements are available, the objective is

to calculate a critical value (c) such that if

each of the n measurements is ≤ c, then the

1-tailed 95-percent UCL for μ is ≤ the

verification limit. Since the product of the n

individual tail probabilities must equal 0.05,

the appropriate 1-tail probability for each

measurement individually is the nth root of

0.05.

For example, if n = 3, then the appropriate

1-tail probability for each measurement is the

cube root of 0.05, or 0.3684. The standard

normal confidence coefficient corresponding

to this tail probability is 0.336. Therefore,

when all three measurements have the same

value (X), the UCL is X·(1+0.336·CV).

Substituting the appropriate CV estimate, the

UCL is X·1.0336 for coal mine dust or

X·1.0302 for crystalline silica. Consequently,

to obtain the critical value, the verification

limit is first divided by 1.0336 (coal mine

dust) or 1.0302 (crystalline silica dust) and

then truncated to the desired number of

decimal digits. This yields 1.93 mg/m3 for

coal mine dust and 97 μg/m3 for respirable

crystalline silica dust.

The confidence coefficients used to

establish critical values by this method are as

follows:

n—Confidence Coefficient 

1 1.645

2 0.760

3 0.336

4 0.068

For n > 4, the confidence coefficient is less

than 0.068.

It should be noted that although the critical

value calculated for n ≥ 4 is slightly below

the verification limit for both types of dust,

for simplicity it was set equal to the

verification limit as a close approximation.

Appendix B—References

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American Iron and Steel Institute v. OSHA,

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American Textile Manufacturers’ Institute

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investigation into the relationship between

coal workers’ pneumoconiosis and dust

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XII. Regulatory Text

List of Subjects

30 CFR part 70

Coal, Mine safety and health,

Underground coal mines, Respirable

dust.

30 CFR part 75

Coal, Mine safety and health,

Underground coal mines, Ventilation.

30 CFR part 90

Coal, Mine safety and health.

Dated: June 20, 2000.

J. Davitt McAteer,

Assistant Secretary for Mine Safety and

Health.

Accordingly, it is proposed to amend

Chapter I of Title 30 of the Code of

Federal Regulations as follows:

PART 70—MANDATORY HEALTH

STANDARDS—UNDERGROUND COAL

MINES

1. The authority citation for part 70

continues to read as follows:

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

961, unless otherwise noted.

2. Section 70.2 is revised to read as

follows:

Subpart A—General

Sec.

70.2 Definitions.

Subpart A—General

§ 70.2 Definitions.

(a) Act means the Federal Mine Safety

and Health Act of 1977, Public Law 91–

173, as amended by Public Law 95–164,

30 U.S.C. 801 et. seq.

(b) Active workings means any place

in a coal mine where miners are

normally required to work or travel.

(c) Concentration means an 8-hour

MRE equivalent measure of the amount

of respirable dust per unit volume of air.

The concentration of respirable dust is

determined in two steps. First, divide

the weight of dust in milligrams

collected on the filter of an approved

sampling device by 480 minutes times

the sampler flow rate. Second, multiply

that concentration by a constant factor

prescribed by the Secretary for the

approved sampling device used. The

product is the equivalent concentration

as measured with an MRE instrument.

(d) Critical value means the highest

full shift dust concentration

measurement that MSHA will accept in

approving a mine ventilation plan or

interim plan.

(e) Designated area (DA) means an

area of a mine identified by the operator

under § 75.371(t) of this title and

approved by the District Manager, or

identified by the Secretary. Each DA

will be identified by a four-digit

identification number assigned by

MSHA.

(f) Designated occupation (DO) means

the occupation or work location on a

mechanized mining unit that has been

determined by results of respirable dust

samples to have the greatest respirable

dust concentration.

(g) District Manager means the

manager of the Coal Mine Safety and

Health District in which the mine is

located.

(h) Dust control parameters means the

engineering or environmental controls,

maintenance procedures, and any other

requirements specified in each

ventilation plan that are being used on

the mechanized mining unit and

throughout the mine to control the level

of respirable coal mine dust and

respirable quartz dust in the work

environment.

(i) Engineering or environmental

controls means any method to control

the level of respirable coal mine dust

and quartz dust in the work

environment by either reducing dust

generation or by suppressing, diluting,

capturing or diverting the dust being

generated during the mining process. It

does not include powered, air-purifying

respirators (PAPRs) or any other type of

personal protection equipment.

(j) Full shift means an entire work

shift including travel time but

excluding, for purposes of bimonthly

sampling only, any time in excess of 480

minutes.

42178 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

(k) Interim ventilation plan means a

ventilation plan for a longwall operation

under which operators are allowed to

use PAPRs or verifiable administrative

controls.

(l) Longwall face means a working

place in a coal mine where coal is

extracted from the exposed face or seam

using the longwall method of mining.

(m) Longwall mining section means

the area of the coal mine employing

longwall mining, from the loading point

of the section up to and including the

longwall face. The loading point is also

included.

(n) Material produced means coal

and/or any other substance extracted by

a mechanized mining unit during any

production shift.

(o) Mechanized mining unit (MMU)

means a unit of mining equipment

including hand loading equipment used

for the production of material; or a

specialized unit which utilizes mining

equipment other than specified in

§ 70.206 for the production of material.

MSHA assigns each MMU a four digit

identification number. The MMU

retains the identification number

regardless of where the unit relocates

within the mine. When two sets of

mining equipment are provided in a

series of working places and only one

production crew is employed at any

given time on either set of mining

equipment, the two sets of equipment

are identified as a single MMU. When

two or more MMUs are simultaneously

engaged in the production of material

within the same working section, each

such MMU is identified separately.

(p) MRE means the Mining Research

Establishment of the National Coal

Board, London, England.

(q) MRE instrument means the

gravimetric dust sampler with a four

channel horizontal elutriator developed

by the Mining Research Establishment

of the National Coal Board, London,

England.

(r) MSHA means the Mine Safety and

Health Administration of the

Department of Labor.

(s) Powered, air-purifying respirator

(PAPR) means a type of loose-fitting

helmet respirator with a visor that uses

a blower to force the ambient air

through air-purifying elements to

deliver filtered air into the miner’s

breathing area.

(t) Production shift means:

(1) With regard to a mechanized

mining unit, a shift during which

material is produced, or

(2) With regard to a designated area of

a mine, a shift during which material is

produced and routine day-to-day

activities are occurring in the designated

area.

(u) Provisional ventilation plan means

a ventilation plan which has been

approved by the District Manager

pending verification by MSHA of the

effectiveness of the plan’s dust control

parameters.

(v) Quartz means crystalline silicon

dioxide (SiO2) as measured by MSHA’s

Analytical Method P–7: Infrared

Determination of Quartz in Respirable

Coal Mine Dust.

(w) Respirable dust means dust

collected with a sampling device

approved by the Secretary and the

Secretary of Health and Human Services

in accordance with part 74 (Coal Mine

Dust Personal Sampler Units) of this

title. Sampling device approvals issued

by the Secretary of the Interior and

Secretary of Health, Education, and

Welfare are continued in effect.

(x) Secretary means the Secretary of

Labor or delegate.

(y) Verifiable administrative control

means any work practice that can

significantly reduce daily exposure to

respirable dust hazards by altering the

way in which work is performed and

which:

(1) Can be reviewed to confirm its

proper implementation,

(2) Is clearly understood by miners,

and

(3) Can be applied consistently over

time.

(z) Verification limits means 2.0 mg/

m3 of respirable coal mine dust and 100

μg/m3 of respirable quartz dust (MREequivalent concentrations) measured

over a full shift.

(aa) Verification production level

(VPL) means the tenth highest

production level recorded in the most

recent thirty production shifts.

(bb) Verification sample means a

valid sample taken on a full shift during

which the amount of material produced

is at or above the VPL and using only

the engineering or environmental

controls and other measures included in

the ventilation plan, at levels not

exceeding 115% of the quantities

specified in the plan.

3. Subpart B is revised to read as

follows:

Subpart B—Dust Standards

70.100 What are the respirable dust

standards when quartz is not present?

70.101 What is the respirable dust standard

when quartz is present?

Subpart B—Dust Standards

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

§ 70.100 What are the respirable dust

standards when quartz is not present?

When quartz is not present:

(a) Each operator shall continuously

maintain the average concentration of

respirable dust in the mine atmosphere

during each shift to which each miner

in the active workings of each mine is

exposed at or below 2.0 milligrams of

respirable dust per cubic meter of air as

measured with an approved sampling

device and in terms of an equivalent

concentration determined in accordance

with § 70.2(c).

(b) Each operator shall continuously

maintain the average concentration of

respirable dust within 200 feet outby the

working faces of each section in the

intake airways at or below 1.0

milligrams of respirable dust per cubic

meter of air as measured with an

approved sampling device and in terms

of an equivalent concentration

determined in accordance with

§ 70.2(c).

§ 70.101 What is the respirable dust

standard when quartz is present?

When the respirable dust in the mine

atmosphere of the active workings

contains more than 5 percent quartz as

determined by samples taken by the

Secretary, the operator shall

continuously maintain the average

concentration of respirable dust in the

mine atmosphere during each shift to

which each miner in the active

workings is exposed at or below a

concentration of respirable dust,

expressed in milligrams per cubic meter

of air as measured with an approved

sampling device and in terms of an

equivalent concentration determined in

accordance with § 70.2(c), computed by

dividing the percent of quartz into the

number 10.

Example: The respirable dust

associated with a mechanized mining

unit or a designated area in a mine

contains quartz in the amount of 20%.

Therefore, the average concentration of

respirable dust in the mine atmosphere

associated with that mechanized mining

unit or designated area shall be

continuously maintained at or below 0.5

milligrams of respirable dust per cubic

meter of air (10/20=0.5 mg/m3 ).

4. Subpart C is revised to read as

follows:

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42179

Subpart C—Verification of

Underground Coal Mine Ventilation

Plan Effectiveness; Use of Approved

Powered, Air-Purifying Respirators;

Use of Verifiable Administrative

Controls; Actions Necessary When in

Violation of Respirable Dust Standard;

and Status Change Reports

Verification of Underground Coal Mine

Ventilation Plan Effectiveness

70.201 Who must have a verified

ventilation plan?

70.202 What is a verified ventilation plan?

70.203 What will trigger the plan

verification process?

70.204 When will MSHA conduct

verification sampling?

70.205 What must I (the operator) do to

comply with this standard?

70.206 Who will MSHA sample and where

will MSHA place the sampling device(s)

when conducting verification sampling?

70.207 How many shifts will MSHA sample

to verify my ventilation plan?

70.208 What if 30 shifts of production data

are not available to establish the

verification production level (VPL)?

70.209 When will MSHA approve my

ventilation plan?

70.210 What must I (the operator) do if a

verification sample exceeds either

verification limit?

70.211 What if verification samples

continue to exceed either verification

limit even though I (the operator) believe

all feasible engineer and environmental

controls are in place?

Use of Approved Powered, Air-Purifying

Respirators

70.212 For my longwall operation, what

must I (the operator) do in order to use

approved PAPRs to supplement

engineering or environmental controls?

70.213 For my longwall operation, when

will MSHA approve my interim

ventilation plan incorporating a PAPR

respiratory protection program?

70.214 For my longwall operation, under

what circumstances may I (the operator)

continue to use PAPRs to supplement

engineering or environmental controls?

70.215 What if an MSHA DO sample

exceeds the applicable dust standard, or

an MSHA sample for a miner required to

wear a PAPR exceeds twice the

applicable dust standard?

Use of Verifiable Administrative Controls

70.216 For my longwall operation, what

must I (the operator) do in order to use

verifiable administrative controls to

supplement engineering or

environmental controls?

70.217 For my longwall operation, when

will MSHA approve my interim

ventilation plan incorporating verifiable

administrative controls?

70.218 For my longwall operation with an

approved interim ventilation plan, what

must I (the operator) do if an MSHA

sample exceeds the applicable dust

standard?

Actions Necessary When in Violation of

Respirable Dust Standards

70.219 What must I (the operator) do if I am

cited for exceeding the applicable dust

standard?

Information to Be Posted on the Mine

Bulletin Board

70.220 What information must I (the

operator) post on the mine bulletin

board?

Status Change Reports

70.221 What action must I (the operator)

take if the operational status of my mine,

MMU, or DA changes?

Subpart C—Verification of

Underground Coal Mine Ventilation

Plan Effectiveness; Use of Approved

Powered, Air-Purifying Respirators;

Use of Verifiable Administrative

Controls; Actions Necessary When in

Violation of Respirable Dust Standard;

and Status Change Reports

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

Verification of Underground Coal Mine

Ventilation Plan Effectiveness

§ 70.201 Who must have a verified

ventilation plan?

All underground coal mine operators

must have a verified ventilation plan.

§ 70.202 What is a verified ventilation

plan?

A verified ventilation plan is a plan

that has been demonstrated as effective,

at a high level of confidence, in

maintaining the concentration of

respirable coal mine dust and quartz

dust in each MMU at or below 2.0 mg/

m3 and 100 μg/m3, respectively. This

demonstration is based on MSHA

verification samples.

§ 70.203 What will trigger the plan

verification process?

MSHA will initiate the plan

verification process when:

(a) You submit a new ventilation plan

under § 75.370 or you amend a

previously approved ventilation plan

under § 75.371(f); or

(b) The District Manager requires you

to change the ventilation plan after

determining that your dust control

parameters no longer effectively control

the concentration of respirable dust in

the working environment of an MMU

under the current mining conditions; or

(c) You propose revisions to a

previously verified ventilation plan and

the District Manager determines that the

proposed revisions may cause the plan

to be inadequate.

§ 70.204 When will MSHA conduct

verification sampling?

The District Manager will notify you

of the schedule for verification sampling

after granting provisional approval of

your ventilation plan. Before you

receive provisional approval, however,

you may be required to change your

plan if the District Manager determines

that your dust control parameters are

inadequate or unsuitable for the current

mining conditions.

§ 70.205 What must I (the operator) do to

comply with this standard?

To comply with this standard, at the

time the District Manager notifies you

that MSHA will conduct verification

sampling you must:

(a) Set your operating conditions so as

to mine at or above the VPL and use

only the dust control parameters and

other measures listed in your plan on

the date scheduled for verification

sampling;

(b) For each MMU to be sampled,

make available records of the amount of

material produced each shift during the

previous six-month period as prescribed

in § 75.370(h);

(c) Provide the additional information

described under § 75.371(f); and

(d) Notify the District Manager if you

cannot meet the conditions described in

paragraph (a) on the scheduled date.

§ 70.206 Who will MSHA sample and where

will MSHA place the sampling device(s)

when conducting verification sampling?

(a) MSHA will sample the

environment of:

(1) The designated occupation (DO);

roofbolter operators; longwall jack

setters; and

(2) Any other occupation designated

by the District Manager.

(b) Unless otherwise directed by the

District Manager, MSHA will take DO

samples by placing the sampling

device(s) in the following locations:

(1) Conventional section using cutting

machine—on the cutting machine

operator or on the cutting machine

within 36 inches inby the normal

working position;

(2) Conventional section shooting off

the solid—on the loading machine

operator or on the loading machine

within 36 inches inby the normal

working position;

(3) Continuous mining section other

than auger-type—on the continuous

mining machine operator or on the

continuous mining machine within 36

inches inby the normal working

position;

(4) Continuous mining machine;

auger-type—on the jacksetter who works

nearest the working face on the return

air side of the continuous mining

machine or at a location that represents

the maximum concentration of dust to

which the miner is exposed;

42180 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

(5) Scoop section using cutting

machine—on the cutting machine

operator or on the cutting machine

within 36 inches inby the normal

working position;

(6) Scoop section shooting off the

solid—on the coal drill operator or on

the coal drill within 36 inches inby the

normal working position;

(7) Longwall section—on the miner

who works nearest the return air side of

the longwall working face or along the

working face on the return side within

48 inches of the corner;

(8) Hand loading section with a

cutting machine—on the cutting

machine operator or on the cutting

machine within 36 inches inby the

normal working position;

(9) Hand loading section shooting off

the solid—on the hand loader exposed

to the greatest dust concentration or at

a location that represents the maximum

concentration of dust to which the

miner is exposed; and

(10) Anthracite mine sections—on the

hand loader exposed to the greatest dust

concentration or at a location that

represents the maximum concentration

of dust to which the miner is exposed.

§ 70.207 How many shifts will MSHA

sample to verify my ventilation plan?

MSHA can approve your ventilation

plan based on only one shift of

sampling, provided all the samples

taken on that shift meet the criteria for

a verification sample and none of them

exceed the critical values for a single

shift specified in §§ 70.209 and 70.213.

We will sample additional shifts if one

verification sample exceeds the

specified critical values, or if any of the

samples taken do not meet the criteria

for a verification sample.

§ 70.208 What if 30 shifts of production

data are not available to establish the

verification production level (VPL)?

If you do not have 30 shifts of

production data to establish a VPL, the

VPL will be the minimum production

level attained on a shift that was

sampled to verify the plan’s

effectiveness. This production level

must be incorporated into the

ventilation plan that is ultimately

approved by the District Manager.

§ 70.209 When will MSHA approve my

ventilation plan?

MSHA will approve your ventilation

plan when:

(a) None of the verification samples

exceed the following critical values for

respirable coal mine dust and quartz

dust:

(1) For respirable coal mine dust, the

critical value is:

(i) 1.71 mg/m3 if samples are collected

for only one shift;

(ii) 1.85 mg/m3 if samples are

collected for two shifts;

(iii)1.93 mg/m3 if samples are

collected for three shifts; and

(iv) 2.0 mg/m3 if samples are collected

for four or more shifts.

(2) For respirable quartz dust, the

critical value is:

(i) 87 ‘‘μg/m3 if samples are collected

for only one shift;

(ii) 93 ‘‘μg/m3 if samples are collected

for two shifts;

(iii) 97 ‘‘μg/m3 if samples are

collected for three shifts; and

(iv) 100 ‘‘μg/m3 if samples are

collected for four or more shifts.

(b) You adjust your plan, if necessary,

to include all the dust control

parameters that were in effect during

verification sampling.

§ 70.210 What must I (the operator) do if a

verification sample exceeds either

verification limit?

If a verification sample exceeds either

verification limit, you must:

(a) Immediately take corrective action

to lower the concentration of respirable

dust in the work environment of the

affected occupation or location to a level

no greater than the applicable

verification limit;

(b) Make approved respiratory

equipment available to affected miners

following the procedures in § 70.300;

and

(c) Within 5 days of receiving results

of verification sampling, submit changes

in your dust control parameters and any

other corrective actions you

implemented to the District Manager for

review. The District Manager will notify

you if your ventilation plan is

provisionally approved under § 70.210

(c).

(1) If your ventilation plan is

provisionally approved, the District

Manager will notify you when MSHA

will start verification sampling over

again, or continue verification sampling.

(2) If your ventilation plan is not

provisionally approved, the District

Manager will require you to make

additional changes in your plan

parameters. Once you have made all

required changes to your plan

parameters, you will receive provisional

approval of your ventilation plan. Then,

the District Manager will notify you

when MSHA will start verification

sampling over again, or continue

verification sampling from the point at

which it stopped.

§ 70.211 What if verification samples

continue to exceed either verification limit

even though I (the operator) believe all

feasible engineering and environmental

controls are in place?

If verification samples continue to

exceed the verification limit and you

believe all feasible engineering and

environmental controls are in place,

then:

(a) If the ventilation plan being

verified is for an MMU that uses a

mining system other than longwall

mining, MSHA may suggest additional

controls for you to implement.

(b) If the MMU employs a longwall

mining system, MSHA may suggest

additional controls for you to

implement; and, you may request in

writing that the Administrator for Coal

Mine Safety and Health determine

whether or not you are using all feasible

engineering or environmental controls

to reduce concentrations of respirable

dust to as low a level as possible; and

(c) If MSHA determines that you are

using all feasible engineering or

environmental on your longwall, based

on its assessment of the suitability of

available control measures to your

particular MMU, MSHA will notify you

that you may use either powered, airpurifying respirators (PAPRs) approved

under 42 CFR 84, or verifiable

administrative controls on an interim

basis to supplement the engineering or

environmental controls you have

implemented to achieve compliance,

until additional feasible engineering or

environmental controls become

available. If you use these supplements,

the DO would be changed from the 060

to the 044 occupation.

Use of Approved Powered, AirPurifying Respirators

§ 70.212 For my longwall operation, what

must I (the operator) do in order to use

approved PAPRs to supplement

engineering or environmental controls?

In order to use PAPRs to supplement

engineering or environmental controls,

you must:

(a) Submit a revised ventilation plan

to the District Manager within 5 days of

receiving notification allowing you to

supplement the engineering or

environmental controls on your

longwall for compliance purposes. Your

plan must include feasible engineering

or environmental controls capable of

maintaining concentrations of respirable

dust in the environment of:

(1) The DO (Occ 044—longwall

operator or the occupation selected by

the District Manager) at or below the

verification limits; and

(2) Any miner working downwind of

the DO, who is required to wear a PAPR,

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42181

at or below two times the verification

limits.

(b) Incorporate in your plan a

respiratory protection program for the

use of PAPRs following the procedures

specified in § 72.710. MSHA’s District

Manager may require you to make

modifications to your respiratory

protection program before granting

provisional approval;

(c) Obtain provisional approval of

your ventilation plan from the District

Manager;

(d) Have MSHA verify your plan’s

effectiveness by sampling the

environment of the DO (Occ 044—

longwall operator) or other occupation

directed by the District Manager and

those miners working downwind of the

DO who are required to wear approved

PAPRs on the longwall face following

the verification sampling procedures in

§§ 70.205 and 70.206;

(e) Maintain and monitor compliance

with the revised ventilation plan; and

(f) Continue to look for improvements

that you can make and implement

feasible solutions when they become

available that would maintain the

environment of the miners required to

wear PAPRs at or below the verification

limits.

§ 70.213 For my longwall operation, when

will MSHA approve my interim ventilation

plan incorporating a PAPR respiratory

protection program?

MSHA will approve your interim

ventilation plan when:

(a) None of the verification samples

for the DO exceed the critical values for

respirable coal mine dust and quartz

dust specified in § 70.209;

(b) None of the verification samples

for the miners working downwind of the

DO, who are required to wear approved

PAPRs, exceed the following critical

values for respirable coal mine dust and

quartz dust:

(1) For respirable coal mine dust, the

value is:

(i) 3.54 mg/m3 if samples are collected

for only one shift;

(ii) 3.77 mg/m3 if samples are

collected for two shifts;

(iii)3.89 mg/m3 if samples are

collected for three shifts;

(iv) 4.0 mg/m3 if samples are collected

for four or more shifts.

(2) For respirable quartz dust, the

value is:

(i) 174 μg/m 3 if samples are collected

for only one shift;

(ii) 187 μg/m 3 if samples are collected

for two shifts;

(iii) 194 μg/m 3 if samples are

collected for three shifts;

(iv) 200 μg/m 3 if samples are

collected for four or more shifts; and

(c) You adjust your plan, if necessary,

to include all the dust control

parameters that were in effect during

verification sampling.

§ 70.214 For my longwall operation, under

what circumstances may I (the operator)

continue to use PAPRs to supplement

engineering or environmental controls?

You may continue to use approved

PAPRs for compliance purposes under

the following conditions:

(a) You implement and maintain all

feasible engineering or environmental

controls on each shift;

(b) You implement and maintain the

PAPR respiratory protection program as

approved by the District Manager;

(c) No MSHA DO sample exceeds the

applicable dust standards, and no

MSHA sample for any miner working

downwind of the DO and required to

wear a PAPR exceeds two times the

applicable dust standards; and

(d) You continue to look for

improvements that you can make and

implement feasible solutions when they

become available that would maintain

the environment of the miners required

to wear PAPRs at or below the

verification limits.

§ 70.215 What if an MSHA DO sample

exceeds the applicable dust standard, or an

MSHA sample for a miner required to wear

a PAPR exceeds twice the applicable dust

standard?

If an MSHA DO sample exceeds the

dust standard you must:

(a) Promptly review your dust control

procedures to determine the cause of the

high dust concentration levels and take

appropriate action to prevent similar

occurrences in the future;

(b) Promptly review the continued

effectiveness of your approved PAPR

respiratory protection program; and

(c) If necessary, make changes to your

dust control parameters and submit

them to the District Manager for review

and approval.

Use of Verifiable Administrative

Controls

§ 70.216 For my longwall operation, what

must I (the operator) do in order to use

verifiable administrative controls to

supplement engineering or environmental

controls?

In order to use administrative controls

for longwall operations you must:

(a) Submit a revised ventilation plan

to the District Manager within 5 days of

receiving notification allowing you to

supplement the engineering or

environmental controls on your

longwall for compliance purposes. The

plan must include the feasible

engineering or environmental controls

being used to reduce the concentrations

of respirable dust on your longwall to as

low a level as possible, the verifiable

administrative controls to be

implemented on the MMU, and a

method for ensuring that the

administrative controls are complied

with at all times;

(b) Obtain provisional approval of

your ventilation plan from the District

Manager;

(c) Have MSHA verify your plan’s

effectiveness by sampling all miners

working along the longwall face,

including the DO (Occ 044—longwall

operator) or other occupation designated

by the District Manager;

(d) Maintain and monitor compliance

with the revised ventilation plan; and

(e) Continue to look for improvements

that you can make and implement

feasible solutions when they become

available that would maintain the

environment of the miners required to

work downwind of the DO and whose

exposure is being controlled by

administrative controls at or below the

verification limits.

§ 70.217 For my longwall operation, when

will MSHA approve my interim ventilation

plan incorporating verifiable administrative

controls?

MSHA will approve your interim

ventilation plan and use of

administrative controls on your

longwall when:

(a) None of the verification samples

exceed the critical values for respirable

coal mine dust and quartz dust specified

in § 70.209; and

(b) Adjust your plan if necessary, to

include all the dust control parameters

that were in effect during verification

sampling.

§ 70.218 For my longwall operation with an

approved interim ventilation plan, what

must I (the operator) do if an MSHA sample

exceeds the applicable dust standard?

If an MSHA sample exceeds the dust

standard you must:

(a) Promptly review your dust control

procedures to determine the cause of the

excessive dust concentration(s) and take

appropriate action to prevent similar

occurrences in the future;

(b) Promptly review the continued

effectiveness of the administrative

controls in use; and

(c) If necessary, make changes to your

dust control parameters and submit

them to the District Manager for review

and approval.

42182 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

Actions Necessary When in Violation of

Respirable Dust Standards

§ 70.219 What must I (the operator) do if I

am cited for exceeding the applicable dust

standard?

If you are cited for exceeding the dust

standard, you must:

(a) Promptly review your dust control

procedures to determine the cause of the

excessive dust concentration(s); and

(b) Take corrective action to lower the

concentration of respirable dust to

comply with the applicable standard

and notify the District Manager within

24 hours after implementing the

corrective action(s). MSHA will then

sample to determine the effectiveness of

your abatement actions or require

reverification of your ventilation plan

under proposed § 70.203. If MSHA

samples demonstrate:

(1) Compliance—you must

incorporate these corrective actions in

your mine ventilation plan. MSHA may

re-verify your ventilation plan after

determining that your dust control

parameters originally approved may be

ineffective in controlling the

concentrations of respirable dust in the

working environment of the MMU

under the current mining conditions.

(2) Noncompliance—the District

Manager may revoke approval of your

mine ventilation plan.

Information to Be Posted on the Mine

Bulletin Board

§ 70.220 What information must I (the

operator) post on the mine bulletin board?

You must post the following

information on the mine bulletin board:

(a) All MSHA sample results;

(b) For each MMU, the engineering

and environmental controls and other

practices in effect on each shift of the

verification process, along with the

associated values of the dust control

parameters measured;

(c) All written notifications from the

District Manager regarding any aspect of

the plan verification process.

(d) You may remove the posted

verification results after the District

Manager approves the plan. You must

post the results of MSHA respirable dust

compliance samples upon receipt for 31

days.

Status Change Reports

§ 70.221 What action must I (the operator)

take if the operational status of my mine,

MMU, or DA changes?

(a) You must report the change in

operational status of the mine, MMU, or

DA to the MSHA District Office or to

any other MSHA office designated by

the District Manager. You must report

status changes in writing within 3

working days after the status change has

occurred.

(b) Each specific operational status is

defined as follows:

(1) Underground mine:

(i) Producing—has at least one

mechanized mining unit producing

material.

(ii) Nonproducing—no material is

being produced.

(iii) Abandoned—the work of all

miners has been terminated and

production activity has ceased.

(2) Mechanized Mining Unit:

(i) Producing—producing material

from a working section.

(ii) Nonproducing—temporarily

ceased production of material.

(iii) Abandoned—permanently ceased

production of material.

(3) Designated Area:

(i) Producing—activity is occurring.

(ii) Nonproducing—activity has

ceased.

(iii) Abandoned—the dust generating

source has been withdrawn and activity

has ceased.

PART 75—[AMENDED]

6. The authority citation for part 75

continues to read as follows:

Authority: 30 U.S.C. 811.

7. Paragraph (h) of § 75.370 of Subpart

D is added to read as follows:

§ 75.370 Mine ventilation plan; submission

and approval.

* * * * *

(h) The operator must record the

amount of material produced by each

MMU during each production shift,

retain the records for six months, and

make the records available to authorized

representatives of the Secretary and the

miners’ representative.

8. Section 75.371 of Subpart D is

amended by revising paragraphs (f) and

(t) to read as follows:

§ 75.371 Mine ventilation plan; contents.

* * * * *

(f) Section and face ventilation

systems used, including drawings

illustrating how each system is used;

and a description of each different dust

suppression system used on equipment

on working sections, including any

specific work practices used to

minimize the dust exposure of

individual miners, along with

information on the location of the roof

bolter(s) during the mining cycle for

each continuous miner section, and the

cut sequence for each longwall mining

section. For plans required to be verified

pursuant to § 70.201, the length of each

normal production shift, the verification

production level (VPL) as defined in

§ 70.2, and additional provisions for the

use of powered, air purifying respirators

(PAPRs) or verifiable administrative

controls required under § 70.212–215

and § 70.216–218, respectively, must be

included for each working section.

* * * * *

(t) The location of each ‘‘designated

area,’’ and the respirable dust measures

used at the dust generating sources for

these locations.

PART 90—[Amended]

9. The authority citation for part 90

continues to read as follows:

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

10. Subpart A is revised to read as

follows:

Sec.

90.1 Scope.

90.2 Definitions.

90.3 Part 90 option; notice of eligibility;

exercise of option.

§ 90.1 Scope.

This part 90 establishes the option of

miners who are employed at

underground coal mines or at surface

work areas of underground coal mines

and who have evidence of the

development of pneumoconiosis to

work in an area of a mine where the

average concentration of respirable dust

in the mine atmosphere during each

shift is continuously maintained at or

below 1.0 milligrams per cubic meter of

air. The rule sets forth procedures for

miners to exercise this option, and

establishes the right of miners to retain

their regular rate of pay and receive

wage increases. The rule also sets forth

the operator’s obligations. This part 90

is promulgated pursuant to section 101

of the Act and supercedes section 203(b)

of the Act.

§ 90.2 Definitions.

(a) Act means the Federal Mine Safety

and Health Act of 1977, Public Law 91–

173, as amended by Public Law 95–164,

30 U.S.C. 801 et seq.

(b) Active workings means any place

in a coal mine where miners are

normally required to work or travel.

(c) Concentration means an 8-hour

MRE equivalent measure of the amount

respirable dust per unit volume of air.

The concentration of respirable dust is

determined in two steps. First, divide

the weight of dust in milligrams

collected on the filter of an approved

sampling device by 480 minutes times

the sampler flow rate. Second, multiply

that concentration by a constant factor

prescribed by the Secretary for the

approved sampling device used. The

product is the equivalent concentration

as measured with an MRE instrument.

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42183

(d) District Manager means the

manager of the Coal Mine Safety and

Health District in which the mine is

located.

(e) Mechanized mining unit (MMU)

means:

(1) A unit of mining equipment

including hand loading equipment used

for the production of material; or

(2) A specialized unit which utilizes

mining equipment other than specified

in § 70.206(c). MSHA assigns each

MMU a four digit identification number.

The MMU retains the identification

number regardless of where the unit

relocates within the mine. When two

sets of mining equipment are provided

in a series of working places and only

one production crew is employed at any

given time on either set of mining

equipment, the two sets of equipment

are be identified as a single MMU.

When two or more MMUs are

simultaneously engaged in the

production of material within the same

working section, each such MMU is

identified separately.

(f) MRE means the Mining Research

Establishment, of the National Coal

Board, London, England.

(g) MRE instrument means the

gravimetric dust sampler with a four

channel horizontal elutriator developed

by the Mining Research Establishment

of the National Coal Board, London,

England.

(h) MSHA means the Mine Safety and

Health Administration of the

Department of Labor.

(i) Normal work duties means duties

which the part 90 miner performs on a

routine day-to-day basis in his or her job

classification at a mine.

(j) Part 90 miner means a miner

employed at an underground coal mine

or at a surface work area of an

underground coal mine who has

exercised the option under the old

section 203(b) program (36 FR 20601,

October 27, 1971), or under § 90.3 (part

90 option; notice of eligibility; exercise

of option) of this part to work in an area

of a mine where the average

concentration of respirable dust in the

mine atmosphere during each shift to

which that miner is exposed is

continuously maintained at or below 1.0

milligrams per cubic meter of air, and

who has not waived these rights.

(k) Quartz means crystalline silicon

dioxide (SiO2) as measured by MSHA’s

Analytical Method P–7: Infrared

Determination of Quartz in Respirable

Coal Mine Dust.

(l) Respirable dust means dust

collected with a sampling device

approved by the Secretary and the

Secretary of Health and Human Services

in accordance with part 74 (Coal Mine

Dust Personal Sampler Units) of this

title. Sampling device approvals issued

by the Secretary of the Interior and

Secretary of Health, Education, and

Welfare are continued in effect.

(m) Secretary means the Secretary of

Labor or a designee.

(n) Secretary of Health and Human

Services means Secretary of Health and

Human Services or Secretary of Health,

Education, and Welfare.

(o) Surface work area of an

underground coal mine means the

surface areas of land and all structures,

facilities, machinery, tools, equipment,

shafts, slopes, excavations, and other

property, real or personal, placed upon

or above the surface of such land by any

person, used in, or to be used in, or

resulting from, the work of extracting

bituminous coal, lignite, or anthracite

from its natural deposits underground

by any means or method, and the work

of preparing coal so extracted, and

includes custom coal preparation

facilities.

(p) Transfer means any change in the

work assignment of a part 90 miner by

the operator and includes:

(1) Any change in occupation code of

a part 90 miner;

(2) Any movement of a part 90 miner

to or from a mechanized mining unit; or

(3) Any assignment of a part 90 miner

to the same occupation in a different

location at a mine.

(q) Underground coal mine means an

area of land and all structures, facilities,

machinery, tools, equipment, shafts,

slopes, tunnels, excavations, and other

property, real or personal, placed upon,

under, or above the surface of such land

by any person, used in, or to be used in,

or resulting from the work of extracting

in such area bituminous coal, lignite, or

anthracite from its natural deposits in

the earth by any means or method, and

the work of preparing the coal so

extracted.

§ 90.3 Part 90 option; notice of eligibility;

exercise of option.

(a) Any miner employed at an

underground coal mine or at a surface

work area of an underground coal mine

who, in the judgment of the Secretary of

Health and Human Services, has

evidence of the development of

pneumoconiosis based on a chest X-ray,

read and classified in the manner

prescribed by the Secretary of Health

and Human Services, or based on other

medical examinations shall be afforded

the option to work in an area of a mine

where the average concentration of

respirable dust in the mine atmosphere

during each shift to which that miner is

exposed is continuously maintained at

or below 1.0 milligrams per cubic meter

of air. Each of these miners shall be

notified in writing of eligibility to

exercise the option.

(b) Any miner who is a section 203(b)

miner on January 31, 1981, shall be a

part 90 miner on February 1, 1981,

entitled to full rights under this part to

retention of pay rate, future actual wage

increases, and future work assignment,

shift and respirable dust protection.

(c) Any part 90 miner who is

transferred to a position at the same or

another coal mine shall remain a part 90

miner entitled to full rights under this

part at the new work assignment.

(d) The option to work in a low dust

area of the mine may be exercised for

the first time by any miner employed at

an underground coal mine or at a

surface work area of an underground

coal mine who was eligible for the

option under the old section 203(b)

program (36 FR 20601, October 27,

1971), or is eligible for the option under

this part by signing and dating the

Exercise of Option Form and mailing

the form to the Chief, Division of

Health, Coal Mine Safety and Health,

MSHA, 4015 Wilson Boulevard,

Arlington, Virginia 22203.

(e) The option to work in a low dust

area of the mine may be re-exercised by

any miner employed at an underground

coal mine or at a surface work area of

an underground coal mine who

exercised the option under the old

section 203(b).

12. Subpart B is revised to read as

follows:

Subpart B—Dust Standards, Rights of Part

90 Miners

Sec.

90.100 Respirable dust standard.

90.101 Respirable dust standard when

quartz is present.

90.102 Transfer; notice.

90.103 Compensation.

90.104 Waiver of rights; re-exercise of

option.

Subpart B—Dust Standards, Rights of

Part 90 Miners

§ 90.100 Respirable dust standard.

After the twentieth calendar day

following receipt of notification from

MSHA that a part 90 miner is employed

at the mine, the operator shall

continuously maintain the average

concentration of respirable dust in the

mine atmosphere during each shift to

which the part 90 miner in the active

workings of the mine is exposed at or

below 1.0 milligrams per cubic meter of

air.

§ 90.101 Respirable dust standard when

quartz is present.

When the respirable dust in the mine

atmosphere of the active workings to

42184 Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules

which a part 90 miner is exposed

contains more than 5 percent quartz, the

operator shall continuously maintain

the average concentration of respirable

dust in the mine atmosphere during

each shift to which a part 90 miner is

exposed at or below a concentration of

respirable dust computed by dividing

the percent of quartz into the number

10. The application of the formula shall

not result in a respirable dust standard

in excess of 1.0 milligrams per cubic

meter of air.

Example: The respirable dust associated

with a part 90 miner contains quartz in the

amount of 20%. Therefore, the average

concentration of respirable dust in the mine

atmosphere associated with that part 90

miner shall be continuously maintained at or

below 0.5 milligrams of respirable dust per

cubic meter of air (10/20=0.5 mg/m3).

§ 90.102 Transfer; notice.

(a) Whenever a part 90 miner is

transferred in order to meet the

respirable dust standard in § 90.100

(Respirable dust standard) or § 90.101

(Respirable dust standard when quartz

is present), the operator shall transfer

the miner to an existing position at the

same coal mine on the same shift or

shift rotation on which the miner was

employed immediately before the

transfer. The operator may transfer a

part 90 miner to a different coal mine,

a newly-created position or a position

on a different shift or shift rotation if the

miner agrees in writing to the transfer.

(b) On or before the twentieth

calendar day following receipt of

notification from MSHA that a part 90

miner is employed at the mine, the

operator shall give the District Manager

written notice of the occupation and, if

applicable, the mechanized mining unit

to which the part 90 miner will be

assigned on the twenty-first calendar

day following receipt of the notification

from MSHA.

(c) After the twentieth calendar day

following receipt of notification from

MSHA that a part 90 miner is employed

at the mine, the operator shall give the

District Manager written notice before

any transfer of a part 90 miner. This

notice shall include the scheduled date

of the transfer.

§ 90.103 Compensation.

(a) The operator shall compensate

each part 90 miner at not less than the

regular rate of pay received by that

miner immediately before exercising the

option under § 90.3 (part 90 option;

notice of eligibility; exercise of option).

(b) Whenever a part 90 miner is

transferred, the operator shall

compensate the miner at not less than

the regular rate of pay received by that

miner immediately before the transfer.

(c) The operator shall compensate

each miner who is a section 203(b)

miner on January 31, 1981, at not less

than the regular rate of pay that the

miner is required to receive under

section 203(b) of the Act immediately

before the effective date of this part.

(d) In addition to the compensation

required to be paid under paragraphs

(a), (b) and (c) of this section, the

operator shall pay each part 90 miner

the actual wage increases that accrue to

the classification to which the miner is

assigned.

(e) If a miner is temporarily employed

in an occupation other than his or her

regular work classification for two

months or more before exercising the

option under § 90.3 (part 90 option;

notice of eligibility; exercise of option),

the miner’s regular rate of pay for

purposes of paragraph (a) and (b) of this

section is the higher of the temporary or

regular rates of pay. If the temporary

assignment is for less than two months,

the operator may pay the part 90 miner

at his or her regular work classification

rate regardless of the temporary wage

rate.

(f) If a part 90 miner is transferred,

and the Secretary subsequently notifies

the miner that notice of the miner’s

eligibility to exercise the part 90 option

was incorrect, the operator shall retain

the affected miner in the current

position to which the miner is assigned

and continue to pay the affected miner

the applicable rate of pay provided in

paragraphs (a), (b), (c) and (d) of this

section, until:

(1) The affected miner and operator

agree in writing to a position with pay

at not less than the regular rate of pay

for that occupation; or

(2) A position is available at the same

coal mine in both the same occupation

and on the same shift on which the

miner was employed immediately

before exercising the option under Sec.

90.3 (Part 90 option; notice of eligibility;

exercise of option) or under the old

section 203(b) program (36 FR 20601,

October 27, 1971).

(i) When such a position is available,

the operator shall offer the available

position in writing to the affected miner

with pay at not less than the regular rate

of pay for that occupation.

(ii) If the affected miner accepts the

available position in writing, the

operator shall implement the miner’s

reassignment upon notice of the miner’s

acceptance. If the miner does not accept

the available position in writing, the

miner may be reassigned and

protections under Part 90 shall not

apply. Failure by the miner to act on the

written offer of the available position

within 15 days after notice of the offer

is received from the operator shall

operate as an election not to accept the

available position.

§ 90.104 Waiver of rights; re-exercise of

option.

(a) A part 90 miner may waive his or

her rights and be removed from MSHA’s

active list of miners who have rights

under part 90 by:

(1) Giving written notification to the

Chief, Division of Health, Coal Mine

Safety and Health, MSHA, that the

miner waives all rights under this part;

(2) Applying for and accepting a

position in an area of a mine which the

miner knows has an average respirable

dust concentration exceeding 1.0

milligrams per cubic meter of air or the

respirable dust standard established by

§ 90.101 (Respirable dust standard when

quartz is present); or

(3) Refusing to accept another

position offered by the operator at the

same coal mine that meets the

requirements of §§ 90.100, 90.101 and

90.102(a) after MSHA dust sampling

shows that the average respirable dust

concentration in his or her present

position exceeds 1.0 milligrams per

cubic meter of air or the respirable dust

standard established by § 90.101

(Respirable dust standard when quartz

is present).

(b) If rights under part 90 are waived,

the miner gives up all rights under part

90 until the miner re-exercises the

option in accordance with § 90.3(e) (part

90 option; notice of eligibility; exercise

of option).

(c) If rights under part 90 are waived,

the miner may re-exercise the option

under this part in accordance with

§ 90.3(e) (part 90 option; notice of

eligibility; exercise of option) at any

time.

13. Subpart C is revised to read as

follows:

90.201 MSHA respirable dust sample

reports; operator status change reporting

requirement.

90.202 Operator status change reports.

§ 90.201 MSHA Respirable dust sample

reports; Operator status change reporting

requirement.

(a) The Secretary shall provide the

operator with a report of the following

data on the MSHA respirable dust

samples as soon as practicable:

(1) The mine identification number;

(2) The mechanized mining unit, if

any, within the mine from which the

samples were taken;

(3) The concentration of respirable

dust, expressed in milligrams per cubic

meter of air, for each valid sample;

(4) The average concentration of

respirable dust, expressed in milligrams

Federal Register / Vol. 65, No. 131 / Friday, July 7, 2000 / Proposed Rules 42185

per cubic meter of air, for all valid

samples;

(5) The occupation code;

(6) The reason for voiding any

samples; and,

(7) The Social Security Number of the

part 90 miner.

(b) Upon receipt, the operator shall

provide a copy of this report to the part

90 miner. The operator shall not post

the original or a copy of this report on

the mine bulletin board.

§ 90.202 Operator status change reports.

If there is a change in the status of a

part 90 miner (such as entering a

terminated, injured or ill status, or

returning to work), the operator must

report the change in the status of the

part 90 miner to the MSHA District

Office or to any other MSHA office

designated by the District Manager.

Status changes shall be reported in

writing within 3 working days after the

status change has occurred.

[FR Doc. 00–16149 Filed 7–6–00; 8:45 am]

BILLING CODE 4510–43–P

DEPARTMENT OF LABOR

Mine Safety and Health Administration

DEPARTMENT OF HEALTH AND

HUMAN SERVICES

Centers for Disease Control and

Prevention

30 CFR Part 72

RIN 1219–AB18

Determination of Concentration of

Respirable Coal Mine Dust

AGENCIES: Mine Safety and Health

Administration (MSHA), Labor.

National Institute for Occupational

Safety and Health (NIOSH), Centers for

Disease Control and Prevention,

Department of Health and Human

Services.

ACTION: Proposed rule; notice of public

hearings; close of record.

SUMMARY: The Mine Safety and Health

Administration (MSHA) and the

National Institute for Occupational

Safety and Health (NIOSH) will hold

public hearings to receive comments on

the joint notice of proposed rulemaking

published in the Federal Register on

July 7, 2000.

The proposal announced that the

Secretary of Labor and the Secretary of

Health and Human Services (the

Secretaries) would find in accordance

with sections 101 and 202(f)(2) (30

U.S.C. §§ 811 and 842(f)(2)) of the

Federal Mine Safety and Health Act of

1977 (Mine Act) that the average

concentration of respirable dust to

which each miner in the active

workings of a coal mine is exposed can

be accurately measured over a single

shift (single, full-shift sampling). The

Secretaries are proposing to rescind a

previous 1972 finding by the Secretary

of the Interior and the Secretary of

Health, Education and Welfare, on the

accuracy of single-shift sampling.

These hearings will be held pursuant

to section 101 of the Mine Act.

Please also see the public hearing

notice addressing verification of dust

control plans (plan verification)

published separately by MSHA in

today’s Federal Register.

DATES: If individuals or organizations

wish to make an oral presentation for

the record at the hearing, please submit

your request at least five days prior to

the hearing date. However, you do not

have to make a written request to speak.

Any unalloted time will be made

available to persons making same-day

requests.

The public hearings will be held on

the following dates and locations:

(1) August 7, 2000 from 8:30 a.m.—5:00

p.m. (Day 1)

August 8, 2000 from 8:30 a.m.—12:00

p.m. (Day 2)(if necessary)

Morgantown, West Virginia

(2) August 10, 2000 from 8:30 a.m.—

5:00 p.m. (Day 1)

August 11, 2000 from 8:30 a.m.—12:00

p.m. (Day 2) (if necessary)

Prestonsburg, Kentucky

(3) August 16, 2000 from 8:30 a.m.—

5:00 p.m. (Day 1)

August 17, 2000 from 8:30 a.m.—12:00

p.m. (Day 2) (if necessary)

Salt Lake City, Utah

To the extent possible, we would like

to hear comments on the notices of

proposed rulemaking in sequence. At

each hearing site during the first part of

Day 1 (until approximately 12:00 p.m.)

we would like to hear comments on the

single, full-shift sampling proposed

rule. The second part of Day 1 we would

like to hear comments on the plan

verification proposal. If a second day of

hearings is necessary at a hearing site,

we would devote this time to hear

comments on the plan verification

proposal.

If necessary, the time can be extended

each day to give all interested parties an

opportunity to present testimony.

The rulemaking record will close on

August 24, 2000.

ADDRESSES: You may use mail, facsimile

(fax), or electronic mail to send us your

requests to make oral presentations at

the public hearings. Clearly identify

your requests and send them— (1) By

mail to Carol J. Jones, Director, Office of

Standards, Regulations, and Variances,

MSHA, 4015 Wilson Boulevard, Room

631, Arlington, VA 22203;

(2) By fax to MSHA, Office of

Standards, Regulations, and Variances,

703–235–5551; or

(3) By electronic mail to

comments@msha.gov.

The hearings will be held on the

following dates and the following

locations:

1. August 7 and 8,* 2000, Holiday Inn,

1400 Saratoga Avenue,

Morgantown, West Virginia 26505,

304–599–1680.

2. August 10 and 11,* 2000, Holiday

Inn, 1887 N US 23, Prestonsburg,

Kentucky 41653, 606–886–0001.

3. August 16 and 17,* 2000, Hilton Salt

Lake City Center, 255 S West

Temple, Salt Lake City, Utah 84101,

801–328–2000.

*if necessary

FOR FURTHER INFORMATION CONTACT:

Carol J. Jones, Director; Office of

Standards, Regulations, and Variances,

MSHA, 4015 Wilson Boulevard,

Arlington, VA 22203–1984; 703–235–

1910.

I. Background

On July 7, 2000, the Secretary of

Labor and the Secretary of Health and

Human Services (the Secretaries) jointly

published a notice of proposed

rulemaking finding in accordance with

sections 101 (30 U.S.C. 811) and

202(f)(2) (30 U.S.C. 842(f)(2)) of the

Federal Mine Safety and Health Act of

1977 (Mine Act) that the average

concentration of respirable dust to

which each miner in the active

workings of a coal mine is exposed can

be accurately measured over a single

shift. The Secretaries are proposing to

rescind a 1972 finding by the Secretary

of the Interior and the Secretary of

Health, Education, and Welfare, on the

accuracy of such single-shift sampling.

II. Conduct of Public Hearings

The hearings will be conducted in an

informal manner with a panel of MSHA

and NIOSH representatives, chaired by

Marvin W. Nichols, Jr. Although formal

rules of evidence or cross examination

will not apply, the presiding official

may exercise discretion to ensure the

orderly progress of the hearings and

may exclude irrelevant or unduly

repetitious material and questions.

Each session will begin with an

opening statement from MSHA and

NIOSH, followed by an opportunity for

members of the public to make oral