National Mining Association v. Secretary, U.S. Department of Labor

Case: 14-11942 Date Filed: 01/25/2016 Page: 1 of 83

[PUBLISH]

IN THE UNITED STATES COURT OF APPEALS

FOR THE ELEVENTH CIRCUIT
________________________

No. 14-11942
________________________

Agency No. RIN 1219-AB64

NATIONAL MINING ASSOCIATION,
ALABAMA COAL ASSOCIATION,
WALTER ENERGY, INC.,
WARRIOR INVESTMENT CO., INC.,

Petitioners,

versus

SECRETARY, U.S. DEPARTMENT OF LABOR,
MINE SAFETY AND HEALTH ADMINISTRATION,

Respondents.

________________________

No. 14-12163
________________________
Agency No. 14-3427

MURRAY ENERGY CORPORATION,
AMERICAN ENERGY CORPORATION,
THE OHIO VALLEY COAL COMPANY,
THE AMERICAN COAL COMPANY,
OHIOAMERICAN ENERGY, INCORPORATED,
UTAHAMERICAN ENERGY, INCORPORATED,
WEST RIDGE RESOURCES, INCORPORATED,
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KENAMERICAN RESOURCES, INCORPORATED,
MURRAY AMERICAN ENERGY, INCORPORATED,
THE HARRISON COUNTY COAL COMPANY,
THE MARION COUNTY COAL COMPANY,
THE MARSHALL COUNTY COAL COMPANY,
THE MONONGALIA COUNTY COAL COMPANY,
THE OHIO COUNTY COAL COMPANY,

Petitioners,

versus

SECRETARY OF LABOR,
MINE SAFETY AND HEALTH ADMINISTRATION,

Respondents.
________________________

Petitions for Review of a Decision of the
Federal Mine Safety and Health Administration
________________________

(January 25, 2016)

Before WILSON, FAY and RIPPLE*, Circuit Judges.

TABLE OF CONTENTS

I. Background................................................................................................ 5
A. Summary of the New Dust Rule .......................................................... 5
B. Positions of the Parties ......................................................................... 9
II. Legislative and Regulatory Context .......................................................12
A. Early Regulation of the Mining Industry and the Coal Act ...............12
B. The Mine Act......................................................................................21
C. Regulatory History Following the Mine Act .....................................27
*
Honorable Kenneth F. Ripple, United States Circuit Judge for the Seventh Circuit,
sitting by designation.

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III. MSHA’s Authority to Regulate ...............................................................31
A. The Statutory Provisions ....................................................................32
B. The Authority to Impose Single-Shift Sampling ...............................34
C. The Authority to Enact Other Substantive Regulations .....................36
IV. Substantive Challenges: The Content of the New Dust Rule .................40
A. Standard of Review ............................................................................40
B. Single-Shift Sampling ........................................................................44
1. Statutory and accuracy-related challenges ...............................45
2. Feasibility of single-shift sampling..........................................54
C. Technological Feasibility of Other Major Provisions
of the New Dust Rule .........................................................................56
1. Mandatory use of the CPDM ...................................................57
a. Accuracy challenges to the CPDM................................59
b. Assumptions underlying MSHA data and requests
to supplement the record before the court .....................61
c. Malfunction rate of the CPDM ......................................63
d. Performance at varying temperatures
and humidities ................................................................66
e. CPDM as an impediment to miners’ ability
to perform work .............................................................68
f. Availability of the CPDM..............................................68
2. The silica standards ..................................................................69
3. The cumulative effect of the New Dust Rule’s
changes .....................................................................................73
D. Economic Feasibility ..........................................................................74
E. Other Challenges ................................................................................78
1. National regulation...................................................................78
2. Use of respirators to achieve air quality standards ..................81
3. Experience under other health and safety laws........................82
Conclusion ..............................................................................................................83

RIPPLE, Circuit Judge:

On May 1, 2014, the Secretary of Labor published in the Federal Register a

Final Rule for the Mine Safety and Health Administration (“MSHA”) entitled

Lowering Miners’ Exposure to Respirable Coal Mine Dust, Including Continuous

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Personal Dust Monitors, 79 Fed. Reg. 24,814 (codified at 30 C.F.R. pts. 70, 71, 72,

75, 90) (“New Dust Rule”). Two separate groups, representing the coal industry, 1

then brought pre-enforcement challenges in the Courts of Appeals for the Sixth and

Eleventh Circuits. The Panel on Multidistrict Litigation consolidated the

challenges here. The petitioners first challenge the authority of MSHA, an agency

within the Department of Labor, to issue the rule under the Federal Mine Safety

and Health Act of 1977 (“Mine Act”), see Pub. L. 95-164, codified as amended at

30 U.S.C. § 801 et seq. Specifically, the petitioners submit that, on many of the

subjects covered by the rule, MSHA is required to act in concert with the Secretary

of Health and Human Services (“HHS”) and her designee, the National Institute for

Occupational Safety and Health (“NIOSH”). Second, the petitioners challenge the

substance of the rule, raising a variety of detailed objections.

On the first challenge, we now conclude that, consistent with the plain

language of the statute and with the earlier precedent of this court, the statute as

amended clearly evinces a congressional intent that, although it must consider the

advice of NIOSH, MSHA has the sole responsibility to issue regulations covering

the subjects addressed by this rule. Here, as anticipated by the statute, MSHA

received the views of NIOSH on every required topic. Nothing more is required.
1
The petitioners in Case No.14-11942 are the National Mining Association and several
Alabama-based coal mine operators. The petitioners in Case No. 14-12163 are also coal mine
operators; we will refer to them collectively as “Murray Energy.”

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With respect to the second challenge, we conclude that MSHA’s decades-long

effort, culminating in the publication of this rule, adequately took into account the

scientific evidence of record and arrived at conclusions which, given MSHA’s

expertise, are worthy of deference. We therefore deny the petitions for review.

I. Background

A. Summary of the New Dust Rule

For nearly sixty years, Congress and various federal agencies working at its

behest have worked to improve safety and health standards for workers in our

Nation’s mines. A primary focus of this effort has been respirable coal dust

(“RCD”)—dust generated by coal mining that is sufficiently small to enter a

miner’s respiratory system. Inhalation of RCD puts coal workers at risk for

pulmonary diseases, including coal worker’s pneumoconiosis (“CWP,” commonly

known as Black Lung Disease), silicosis, chronic obstructive pulmonary disease,

emphysema, and chronic bronchitis. The regulation under review is the latest

effort to address this hazard.

In 2010, MSHA, acting alone, proposed the New Dust Rule to address RCD

and its known health outcomes. Lowering Miners’ Exposure to Respirable Coal

Mine Dust, Including Continuous Personal Dust Monitors, 75 Fed. Reg. 64,412

(proposed Oct. 19, 2010). In our review of an earlier and very similar regulatory

attempt, National Mining Ass’n v. Secretary of Labor, 153 F.3d 1264, 1269 (11th

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Cir. 1998), we expressed concern that MSHA’s effort had failed to determine the

economic feasibility of single-shift sampling, the same monitoring process at issue

in this case. In response to our decision, MSHA initiated a new rulemaking and, as

part of that process, issued an economic analysis addressing that concern. It also

opened the record for comment and extended the comment period three times,

finally closing it in June 2011. After making alterations to respond to the

comments received to its proposed rule, MSHA promulgated its final rule in 2014.

79 Fed. Reg. 24,814.

The New Dust Rule phases in a series of significant changes to RCD

regulations over a two-year period, beginning in August 2014. The first phase saw

the implementation of three basic changes: (1) mine operators began to take air

quality samples over the entire shift of a miner rather than over a maximum of

eight hours, or a miner’s shift, if shorter, 30 C.F.R. § 70.201(c); (2) mine operators

were required to take samples over a “normal production shift,” now defined as

one in which the amount of material produced is “at least equal to 80 percent of the

average production recorded by the operator for the most recent 30 production

shifts” rather than one where production was only required to be at least 50 percent

of the average of the prior five bimonthly samples, id. § 70.2; and (3) for the first

time, compliance determinations would be based on Excessive Concentration

Values (“ECVs”), id. § 70.206(e), (f). ECVs are measurements of RCD so high

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that, as a statistical matter and accounting for a certain amount of measurement

uncertainty, they demonstrate with 95 percent certainty that the true concentration

of RCD exceeded the allowable limit. The use of ECVs allows operators the

benefit of some margin of measurement-related error by requiring not only that the

regulatory RCD standard be exceeded, but that it be exceeded by a margin that

assures for MSHA, with a degree of statistical confidence, that the measurement

demonstrating noncompliance was not erroneous.2 When an on-site MSHA

inspector sees a single, full-shift sample with an ECV, MSHA will issue a citation

to the operator, id. § 72.800. When an operator sees a single, full-shift sample

with an ECV, it must take immediate corrective action to reduce RCD

concentration and make available respiratory equipment to affected miners, id.

§ 70.206(e). If two or more samples by an operator in the preceding five exceed

the ECV, or if the average of all five exceeds the ECV, MSHA will issue a citation.

Id. § 70.206(f). The reliance on individual sample results is a significant change

2
MSHA notes, by way of example, that if the applicable limit is 1.5 milligrams per cubic
meter, ECVs resulting in citations are 1.79 and 1.70 for measurements taken with coal mine dust
personal sampler units (“CMDPSUs”) and Continuous Personal Dust Monitors (“CPDMs”),
respectively. MSHA Br. 50 n.26; Lowering Miners’ Exposure to Respirable Coal Mine Dust,
Including Continuous Personal Dust Monitors, 79 Fed. Reg. 24,814, 24,980, Table 70-1 (listing
ECVs applicable to single-shift measurements) and Table 70-2 (listing ECVs applicable to 5 or
15 full-shift measurements); see also infra pp. 30–31, 49–50 & note 24 (regarding sampling
devices).

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from the prior sampling regime, which is based on multi-shift averaging. It is also

at the core of the petitioners’ objections.

In the next phase, commencing in February 2016, operators must use

Continuous Personal Dust Monitors (“CPDMs”) to measure concentrations in the

dustiest jobs at each section. Id. § 70.201.3 Sampling frequency also increases: on

a quarterly basis, fifteen samples must be taken on consecutive normal production

shifts in the designated occupation, and then fifteen samples in other designated

occupations; prior standards required only five designated occupation samples

bimonthly. Id. § 70.208(a). 4 Over this longer sampling period, when three or more

of the fifteen samples meet the ECV, or when the average of all fifteen exceeds the

ECV, MSHA will issue a citation. Id. § 70.208(f).

In the final phase, beginning in August 2016, the maximum acceptable

concentration limit of RCD reduces to 1.5 milligrams per cubic meter (mg/m3). Id.

§ 70.100(a)(2). Notably, NIOSH’s 1995 Criteria Document called for a further

3
Continuing from the 1980 standard, the rule requires measurements at the “designated
occupation,” which is the job with the highest dust exposure on a section. See 30 C.F.R. § 70.2.
On a continuous mining section, it is the continuous mining machine operator; on the longwall
mining section it is the tailgate-side shearer operator. Id. § 70.208(b)(3), (7). The rule also
requires measurements at “other designated occupations,” drawn from a list of ten other jobs, see
id. § 70.208(b), which MSHA describes as the next one-to-four dustiest locations, depending on
the structure of the mine.
4
The proposed rule would have required constant monitoring, seven days a week, fifty‑
two weeks a year, in the “designated occupation.” See Lowering Miners’ Exposure to Respirable
Coal Mine Dust, Including Continuous Personal Dust Monitors, 75 Fed. Reg. 64,412, 64,489
(proposed Oct. 19, 2010); see supra note 3.

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reduction to 1.0 mg/m3, see I-QRA-23 at 108,5 and the proposed rule itself had

accepted that recommendation and required an accelerated timetable for

compliance, 75 Fed. Reg. at 64,419, 64,492. For areas of the mine and mine

workers in which a lower a 1.0 mg/m3 standard already applied (because they are

in intake air entries or otherwise less dusty areas), the standard will become 0.5

mg/m3. 30 C.F.R. §§ 70.100(b), 90.100. The rule also changes the method of

calculating the lower RCD values applicable to any mining operation where

respirable quartz dust (also called respirable silica dust) is present, although it

maintains current absolute limits of 0.1 mg/m3 of respirable quartz.

B. Positions of the Parties

Within this context, we address the contentions of the parties. The

petitioners submit that MSHA has exceeded its authority. They first maintain that,

by promulgating the New Dust Rule, the Secretary of Labor has rescinded

unilaterally a 1972 Joint Finding of the Secretaries of Labor and of HHS under

section 202(f) of the Mine Act, 30 U.S.C. § 842(f). That Joint Finding had

determined that reliance on a single sample of RCD levels would be inaccurate and

ought not be the basis for compliance determinations. In the petitioners’ view,

because the 1972 Joint Finding was issued jointly by the Secretaries of Labor and
5
I-QRA-23 is the designation chosen by MSHA to refer to a particular document in the
administrative record. We shall, for the sake of consistently, use the numbering system provided
by the parties when referring to the administrative record.

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of HHS, those Secretaries must act together to rescind it. For the same reason, the

petitioners attack the new exposure limits, schedules and requirements

promulgated under the New Dust Rule. They read section 202(a), 30 U.S.C. §

842(a), as requiring joint rulemaking and promulgation by the Secretaries of Labor

and of HHS. Indeed, they continue, section 202(d) of the Mine Act, 30 U.S.C. §

842(d), reserves to HHS alone the authority to promulgate a schedule reducing

RCD exposures below the levels set forth in the statute.

Turning to the substance of the New Dust Rule, the petitioners take issue

with the sampling regime set up by that regulation. Noting that section 202(a) of

the Mine Act, 30 U.S.C. § 842(a), requires that RCD sampling be accurate, they

claim that the regulation permits too wide a variation to meet that statutory

criterion. They urge us to hold that, under the first step of the analysis set forth in

Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837,

104 S. Ct. 2778 (1984), the regulation is invalid. The petitioners continue that,

even if we determine that the statutory scheme is ambiguous, we should hold that

the promulgation of the New Dust Rule was arbitrary and capricious because

MSHA, acting on behalf of the Secretary of Labor, failed to demonstrate the

technological and economic feasibility of the Final Rule. They submit that MSHA

ignored the record evidence that single-shift sampling and a new sampling device

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will increase, significantly, the possibility of inaccurate results. In their view,

MSHA simply did not rely on the best available scientific evidence and experience.

The Secretary of Labor takes, as might be expected, a distinctly contrary

view. He maintains that the Mine Act, through section 101(a), 30 U.S.C. § 811(a),

vests in the Secretary of Labor the authority to develop and to promulgate revised

and improved mandatory health standards. As he reads the Act, the Secretary of

HHS has the authority to recommend that certain criteria be established relating to

harmful physical agents, but the authority to conduct rulemaking proceedings and

to promulgate regulations belongs exclusively to the Secretary of Labor.

Consequently, he reasons, he acted well within the bounds of his statutory

authority in receiving from NIOSH its Criteria Document recommending extensive

changes in the then-existing dust rules and incorporating some of them in the New

Dust Rule.

Turning to the petitioners’ substantive objections, the Secretary maintains

that he reasonably determined that single-shift sampling accurately represents the

average concentration of respirable dust in the mine during each shift. He points

out that sampling methods and technology have improved since the 1972 Joint

Finding and that studies have determined that single-shift sampling meets the

criterion for accuracy recommended by NIOSH. Relying on standards developed

by MSHA and NIOSH, a research entity within the Department of HHS, he further

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maintains that CPDMs are accurate and reliable instruments for the measurement

of coal dust and will be available by the designated implementation date. He

rejects the argument that respirators are more effective than the new device; in his

view, the statute requires mine operators to comply with air quality standards

without resort to respirators. He further maintains that the cost of compliance with

the New Dust Rule amounts to less than one percent of annual revenues.

The Secretary also rejects the suggestion that, instead of the New Dust Rule,

he should have promulgated a regional silica rule. In the Secretary’s view, studies

continue to show that miners in all regions of the United States continue to develop

CWP. Agencies have the prerogative, he submits, to prioritize their regulatory

agendas and to address different problems in different rulemaking proceedings.

Accordingly, the Secretary urges us to determine that the New Dust Rule is

technologically and economically feasible.

II. Legislative and Regulatory Context

A. Early Regulation of the Mining Industry and the Coal Act

Before we analyze the specific challenges brought to us by the parties, we

pause to give these submissions historical context by examining the overall

statutory and regulatory scheme that governs mine health and safety issues in the

United States.

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From the late 19th century until the middle 20th, Congress enacted several

discrete measures to increase mine safety. These measures established some

minimum safety requirements, prohibited labor by children under twelve,

established the Bureau of Mines in the Department of the Interior, and in 1947,

authorized the development of safety regulations.6 Despite these efforts, mining,

an essential occupation to the commercial health of a growing industrial society,

remained one of the most dangerous occupations in the Nation. In 1967–68, the

Country experienced a series of mine accidents that killed more than 500 miners.

In one incident, a devastating mine explosion near Farmington, West Virginia,

seventy-eight miners died. See H.R. Rep. No. 91-563, at 1 (1969).

Shortly thereafter, Congress enacted the Federal Coal Mine Health and

Safety Act of 1969 (“Coal Act”), Pub. L. 91-173, 83 Stat. 742, codified as

amended at 30 U.S.C. § 801 et seq. Its express goal was to increase safety for

mine workers in the United States. The enacted findings in the Coal Act stated

that:

(a) the first priority and concern of all in the coal mining
industry must be the health and safety of its most precious resource—
the miner;

. . . [and]

6
See generally MSHA, History of Mine Safety and Health Legislation,
www.msha.gov/MSHAINFO/MSHAINF2.HTM (last visited Dec. 20, 2015).

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(c) there is an urgent need to provide more effective means and
measures for improving the working conditions and practices in the
Nation’s coal mines in order to prevent death and serious physical
harm, and in order to prevent occupational diseases originating in
such mines. . . .

Id. § 2. At the outset of the Title specifically setting health standards, the Coal Act

also provided:

Among other things, it is the purpose of this title to provide, to the
greatest extent possible, that the working conditions in each
underground coal mine are sufficiently free of respirable dust
concentration in the mine atmosphere to permit each miner the
opportunity to work underground during the period of his entire adult
working life without incurring any disability from pneumoconiosis or
any other occupation-related disease during or at the end of such
period.

Id. § 201(b).

At the time of its enactment, the Coal Act was the most comprehensive

statute addressing health and safety matters in the Nation’s mines. It set forth the

most stringent requirements to date and, for the first time, provided for civil and

criminal penalties for noncompliance. It also addressed the growing medical

knowledge about the progressive respiratory diseases suffered by coal miners. The

Coal Act set forth “interim mandatory” health and safety standards in Titles II and

III, respectively. Id. §§ 201(a), 301(a). Congress mandated that these interim

standards were to remain “applicable to all underground coal mines until

superseded in whole or in part by improved mandatory” health or safety standards

to be promulgated under the provisions of section 101 of the Act. Id. It is
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significant that the 1969 statute spoke in terms of “interim” standards. From the

very outset, Congress envisioned a shifting landscape as improved health and

safety measures became feasible and therefore implemented a regulatory structure

that could focus on continuous improvement. Indeed, to guard against regulatory

backsliding, the statute mandated that “[n]o improved mandatory health or safety

standard promulgated under this title shall reduce the protection afforded miners

below that provided by any mandatory health or safety standard.” Id. § 101(b).

Among the issues covered by the Coal Act was air quality, known to play a

significant role in the development of the respiratory diseases common among

mine workers. Specifically, section 202 of the Coal Act required coal mine

operators to “take accurate samples of the amount of respirable dust in the mine

atmosphere to which each miner in the active workings of such mine is exposed.”

Id. § 202(a). For the first three years after the Coal Act’s enactment, the

maximum acceptable level of RCD was 3.0 mg/m3 of air. Id. § 202(b)(1).

Following that initial period, the maximum level fell to 2.0 mg/m3. Id. § 202(b)(2).

The statute then contemplated a further reduction according to a schedule

promulgated through regulation, “to a level of personal exposure which will

prevent new incidences of respiratory disease and the further development of such

disease in any person.” Id. § 202(d).

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Notably, the Coal Act became law during a period when Congress addressed

more broadly matters affecting the health and safety of the Nation’s workforce. In

1970, the year following the passage of the Coal Act, Congress enacted the

Occupational Safety and Health Act (“OSH Act”), Pub. L. 91-596, 84 Stat. 1590,

codified as amended at 29 U.S.C. § 651 et seq. This statute created the

Occupational Safety and Health Administration (“OSHA”) in the Department of

Labor and gave it broad regulatory and enforcement authority with respect to

workplace safety standards. The OSH Act also created NIOSH, an agency within

the Department of Health, Education, and Welfare (“HEW”) charged with

conducting research and developing recommendations for the prevention of work-

related injuries and illnesses generally. Id. § 22, 29 U.S.C. § 671; see also Nat’l

Mining Ass’n v. Dep’t of Labor, 292 F.3d 849, 854 (D.C. Cir. 2002) (citing 29

U.S.C. § 671). The statute provided that, following its research, NIOSH would

forward its recommendations to the Secretary of Labor for consideration of

regulatory action through his designee, OSHA. Pub. L. 91-596, § 6(b)(1).

Congress assigned primary responsibility for implementation of the Coal Act

to the Secretary of the Interior. Pub. L. 91-173, § 3(a). But the Act also assigned

specific responsibility to other cabinet-level Departments, including, importantly,

HEW. Section 101 established the procedure by which these Departments would

work together to develop the improved standards. The Secretary of the Interior

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had the responsibility to “develop, promulgate, and revise, as may be appropriate,

improved mandatory safety standards for the protection of life and the prevention

of injuries in a coal mine.” Id. § 101(a) (emphasis added). In arriving at these

standards, however, the Secretary of the Interior was to consult with the Secretaries

of HEW and Labor, and others. Id. § 101(c).

For improved mandatory health standards, i.e., those items addressed

substantively in Title II of the statute, and which are the principal concern of the

present rule, the Coal Act required a more complicated process. In this area, the

Secretary of HEW had the laboring oar and was to “develop and revise, as may be

appropriate, improved mandatory health standards for the protection of life and the

prevention of occupational diseases of miners.” Id. at § 101(d). In arriving at

these standards, the Secretary of HEW likewise was to consult with the Secretaries

of the Interior and Labor, and others. The Coal Act required a somewhat unusual

step after the Secretary of HEW developed comprehensive substantive health

standards: he was directed to “transmit[]” those standards to the Secretary of the

Interior. Id. The Secretary of the Interior then had the responsibility to publish the

HEW-authored proposed mandatory health standards in the Federal Register.

After receiving comments on these proposals, the Secretary of the Interior would

“transmit[]” them to the Secretary of HEW. Id. § 101(e). The Secretary of HEW

would then conduct hearings, if necessary, and review the comments, make public

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findings of fact and substantive decisions, and, thereafter, “direct the Secretary [of

the Interior] to promulgate such standards with such modifications as the Secretary

of [HEW] may deem appropriate.” Id. § 101(e); see also id. §101(g). In sum, the

Secretary of HEW made the substantive decisions on health standards. The

Secretary of the Interior, although generally responsible for implementation of

most of the Coal Act, played a largely ministerial role as the promulgator of those

standards.7

Although section 101 of the Coal Act provided the overarching procedural

mechanism for developing improved mandatory standards, several additional

provisions played supporting roles. Section 201 designated the relevant dust

provisions in section 202 as interim mandatory health standards and provided that

they would remain in effect “until superseded in whole or in part by improved

mandatory health standards promulgated by the Secretary [of the Interior] under

the provisions of section 101 of this Act.” Id. § 201. Several additional

substantive sections directed one or more of the Secretaries to act on a specific

subject, frequently, though not invariably, cross-referencing section 101. See, e.g.,

id. § 202(d) (“[T]he Secretary of [HEW] shall establish, in accordance with the

7
The division of authority was not uncontroversial. Indeed, floor debates questioned the
wisdom of having “one Cabinet-level Secretary . . . develop a set of rules and regulations and
direct another Secretary to adopt them and enforce them.” 115 Cong. Rec. H32021 (daily ed.
Oct. 29, 1969) (statement of Rep. Erlenborn); see also id. at H32022 (statement of Rep. Dent)
(supporting the division of authority).

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provisions of section 101 of this Act, a schedule reducing the average

concentration of respirable dust in the mine atmosphere . . . .”). Other provisions

within section 202’s list of interim mandatory standards directed action by one or

both Secretaries without an internal explicit cross-reference to section 101 or 201.

See, e.g., id. § 202(a) (“Such samples shall be taken by any device approved by the

Secretary [of Interior] and the Secretary of [HEW] and in accordance with such

methods, at such locations, at such intervals, and in such manner as the Secretaries

shall prescribe in the Federal Register . . . .”).

The Coal Act provided that both safety standards, originating with Interior,

and health standards, originating with HEW, were to “be based upon research,

demonstrations, experiments, and such other information as may be appropriate.”

Id. § 101(c), (d). Further, “[i]n addition to the attainment of the highest degree of

. . . protection for the miner,” the statute directed the respective Secretaries to

consider “the latest available scientific data in the field, the technical feasibility of

the standards, and experience gained under this and other health [or safety]

statutes.” Id.

The Coal Act specified two separate, sequential mechanisms for determining

the average dust concentration.8 For the first eighteen months after enactment,

8
The section reads, in full:

(continued . . .)
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measurements were to be taken “over a number of continuous production shifts.”

Id. § 202(f). After that initial eighteen months, the dust concentration was to be

measured “over a single shift only.” Id. However, and central to the issue

presented in this case, if the Secretaries of Interior and HEW jointly found that

such a single measurement did not “accurately represent . . . atmospheric

conditions,” the prior method would continue to be used. Id.

Just months after the enactment of the 1969 Coal Act, the Secretary issued

his first set of mandatory health standards implementing section 202. See

Mandatory Health Standards—Underground Coal Mines, 35 Fed. Reg. 5,544 (Apr.

3, 1970). In 1972, the Secretaries finalized, and published in the Federal Register

under the authority of both Departments, a summary Joint Finding that adoption of

a single-shift testing scheme would not accurately measure the atmospheric

conditions during the shift. Consequently, the multi-test averaging scheme

For the purpose of this title, the term “average concentration” means a
determination which accurately represents the atmospheric conditions with regard
to respirable dust to which each miner in the active workings of a mine is exposed
(1) as measured, during the 18 month period following the date of enactment of
this Act, over a number of continuous production shifts to be determined by the
Secretary [of the Interior] and the Secretary of [HEW], and (2) as measured
thereafter, over a single shift only, unless the Secretary [of the Interior] and the
Secretary of [HEW] find, in accordance with the provisions of section 101 of this
Act, that such single shift measurement will not, after applying valid statistical
techniques to such measurement, accurately represent such atmospheric
conditions during such shift.

Federal Coal Mine Health and Safety Act, Pub. L. 91-173, § 202(f), 83 Stat. 742, 762–63
(1969).

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remained in place. See Notice of Finding That a Single Shift Measurement of

Respirable Dust Will Not Accurately Represent Atmospheric Conditions During

Such Shift, 37 Fed. Reg. 3,833 (Feb. 23, 1972) (“1972 Joint Finding”).

B. The Mine Act

Five years later, in 1977, mining fatalities were still more than four times as

great as the average in other industries. H.R. Rep. No. 95-312, at 3 (1977).

Dissatisfied with progress under the Coal Act, 9 Congress reenacted, amended, and

consolidated the Coal Act and various other provisions of law, renaming it the

Federal Mine Safety and Health Act (“Mine Act”), see Federal Mine Safety and

Health Amendments Act, Pub. L. 95-164, 91 Stat. 1290. Procedurally, it made

significant changes to its predecessor. In considering the Mine Act, the Senate

Committee on Resources concluded that the prior enforcement efforts

“demonstrated a basic conflict in the missions” of the Department of the Interior,

which aimed to “maximiz[e] production in the extractive industries,” a goal “not

wholly compatible with the need to interrupt production,” a “necessary adjunct of

the enforcement scheme.” 10 To remove this conflict, the Mine Act designated the

9
“[D]espite . . . considerable Congressional attention, our nation still experiences deaths
and serious injuries in our mines at a rate which casts shame on an advanced, industrialized
society. Every working day of the year, at least one miner is killed and sixty-six miners suffer
disabling injuries in our nation’s mines.” S. Rep. No. 95-181, at 4 (1977), reprinted in 1977
U.S.C.C.A.N. 3401, 3404.
10
The relevant section of the Senate Committee Report reads, in full:
(continued . . .)
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Secretary of Labor as having principal authority to implement the statute. It also

created MSHA within the Department of Labor—a Department with experience on

the issues of worker safety and with new divisions dedicated fully to safety issues.

The statute placed within MSHA regulatory authority over mining health and

safety standards. Mine Act § 101(a), 30 U.S.C. § 811(a); 29 U.S.C. § 557a

(creating MSHA and authorizing and directing the Secretary of Labor to fulfill his

functions under the Mine Act through MSHA). 11 Indeed, in making the shift from

the Department of the Interior to the Department of Labor, the report of the House

Committee on Education and Labor accompanying the Mine Act stated:

The Secretary responsible for the health and safety of miners will no
longer be the Secretary of the Interior, but rather the Secretary of

The history of the Interior Department’s enforcement of these laws, either
by the Bureau of Mines or by MESA, demonstrated a basic conflict in the
missions of the Department. In past years, the Department has pursued the goal of
maximizing production in the extractive industries, which was not wholly
compatible with the need to interrupt production which is the necessary adjunct of
the enforcement scheme under the Metal and Coal Acts: even though, in the
Committee’s view, over the long-run, improved health and safety promotes
greater productivity through reduction of “down-time” and improved employee
morale. In addition, lowered workers’ compensation premiums which should
result from improved safety and health, can be expected to lower production
costs. On the other hand, no conflict could exist if the responsibility for enforcing
and administering the mine safety and health laws was assigned to the Department
of Labor since that Department has as its sole duty the protection of workers and
the insuring of safe and healthful working conditions.

Id. at 5.
11
The functions assigned to the Secretary of the Interior under the Coal Act were carried
out from 1973–77 by the Mining Enforcement and Safety Administration (“MESA”), a
predecessor entity to MSHA.

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Labor, who represents an agency that puts the welfare of workers
above all other considerations. The committee believes that by
transferring administration of the miner health and safety program,
and by upgrading legislative provisions applicable to metal and
nonmetal miners through consolidation of all miners under one safety
law, the Nation will be better able to meet the dual objectives of
increased production of mineral and energy resources, and protection
of the sacred lives of those members of our society who toil in the
mines to keep our country running efficiently.

H.R. Rep. No. 95-312, at 2 (1977) (emphasis added).

In addition to the transfer of principal authority from Interior to Labor, the

Mine Act also substantially revised the general regulatory procedures. Under the

Coal Act, health standards and safety standards were addressed separately. As we

have noted earlier, the development of health standards specifically involved a

two-step process in which the Secretary of HEW developed substantive standards,

and the Secretary of Interior promulgated these in a somewhat ministerial fashion.

Under the Mine Act, however, health and safety standards both are entrusted to the

Secretary of Labor under a single process, although the Secretary of HHS, 12

through NIOSH, has a very significant role in the process. Specifically, the Mine

Act directs the Secretary of Labor (acting through MSHA) to “develop,

promulgate, and revise as may be appropriate, improved mandatory health or

safety standards for the protection of life and prevention of injuries in coal or other

12
At the time the Mine Act was passed, the Department was still known by its former
name, HEW. For ease of reading, we shall use its current name, HHS, in our discussion.

23
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mines.” Mine Act § 101(a), 30 U.S.C. § 811(a) (emphasis added). 13 The Mine Act

gives a broad grant of authority to the Secretary of Labor and directs that

“[w]henever . . . upon the basis of information submitted to him in writing by”

interested parties, including the Secretary of HHS, NIOSH, or others, the Secretary

of Labor “determines that a rule should be promulgated,” he may act. Id. §

101(a)(1), 30 U.S.C. § 811(a)(1). However, when he

receives a recommendation, accompanied by appropriate criteria,
from [NIOSH] that a rule be promulgated, modified, or revoked, the
Secretary must, within 60 days after receipt thereof, refer such
recommendation to an advisory committee . . . , or publish such as a
proposed rule . . . , or publish in the Federal Register his
determination not to do so, and his reasons therefor.

Id. Significantly for our purposes, a similar process is set forth in the statute for

the recommendations received of the Secretary of HHS regarding toxic agents

found in mines.14 Consistent with the role it plays elsewhere in occupational

13
See NIOSH, National Respiratory Diseases Research Program: 1.2 Legislative
Foundations, http://www.cdc.gov/niosh/nas/rdrp/ch1.2.htm (last visited Dec. 21, 2015)
(“Congress has set a clear division between the research function of NIOSH; and the regulatory
and enforcement functions of MSHA and OSHA. Although NIOSH works together with MSHA
and OSHA to achieve the common goal of protecting worker safety and health, NIOSH
simultaneously maintains its unique identity as the sole federal government organization
primarily charged to conduct occupational safety and health research.”).
14
Specifically, the statute provides:

(6)(A) The Secretary [of Labor], 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. Development of mandatory standards
(continued . . .)
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safety, therefore, NIOSH was given a consultative, rather than regulatory, role

under the main provision of the Mine Act addressing the development of health

and safety standards.15

under this subsection shall be based upon research, demonstrations, experiments,
and such other information as may be appropriate. In addition to the attainment of
the highest degree of health and safety protection for the miner, other
considerations shall be the latest available scientific data in the field, the
feasibility of the standards, and experience gained under this and other health and
safety laws. Whenever practicable, the mandatory health or safety standard
promulgated shall be expressed in terms of objective criteria and of the
performance desired.

(B) The Secretary of [HHS], as soon as possible after November 9, 1977,
but in no event later than 18 months after such date and on a continuing basis
thereafter, shall, for each toxic material or harmful physical agent which is used
or found in a mine, determine whether such material or agent is potentially toxic
at the concentrations in which it is used or found in a mine. The Secretary of
[HHS] shall submit such determinations with respect to such toxic substances or
harmful physical agents to the Secretary [of Labor]. Thereafter, the Secretary of
[HHS] shall submit to the Secretary [of Labor] all pertinent criteria regarding any
such substances determined to be toxic or any such harmful agents as such criteria
are developed. Within 60 days after receiving any criteria in accordance with the
preceding sentence relating to a toxic material or harmful physical agent which is
not adequately covered by a mandatory health or safety standard promulgated
under this section, the Secretary [of Labor] shall either appoint an advisory
committee to make recommendations with respect to a mandatory health or safety
standard covering such material or agent in accordance with paragraph (1), or
publish a proposed rule promulgating such a mandatory health or safety standard
in accordance with paragraph (2), or shall publish his determination not to do so.

30 U.S.C. § 811(a)(6); see also Mine Act § 101(a)(6).
15
“Although NIOSH is authorized by 29 U.S.C. § 671(c)(1) to ‘develop and establish
recommended occupational safety and health standards,’ this provision is not part of the Mine
Act. The Mine Act references NIOSH and HHS as providers of information to MSHA, see 30
U.S.C. § 811(a)(1) . . . .” Nat’l Mining Ass’n v. Mine Safety & Health Admin., 599 F.3d 662,
671–72 (D.C. Cir. 2010).

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Perhaps in recognition that many of the Coal Act’s initial interim standards

were either in force in the industry or already had been superseded with improved

standards set by initial regulations, see generally 35 Fed. Reg. 5,544, the Mine Act

itself made no substantive changes to the Coal Act’s interim mandatory health

standards.16 Within Title II, therefore, specific duties assigned under the Coal Act

to the Secretary of HEW (now HHS) were preserved. Among these are a number

of provisions with significance to the present case, including section 202(a), 30

U.S.C. § 842(a), which requires samples of RCD to be taken in the mines “by any

device approved by the Secretary [of Labor] and the Secretary of [HHS] and in

accordance with such methods, at such locations, at such intervals, and in such

manner as the Secretaries shall prescribe in the Federal Register.” Additionally,

section 202(d) provides that “the Secretary of [HHS] shall establish, in accordance

with the provisions of section 101 of this Act, a schedule reducing the average

concentration of respirable dust in the mine atmosphere.” See also 30 U.S.C.

§ 842(d). Section 202(e), 30 U.S.C. § 842(e) provides that “concentrations of

respirable dust in this title mean the average concentration of respirable dust

measured with a device approved by the Secretary [of Labor] and the Secretary of

[HHS],” and, likewise, section 202(h), 30 U.S.C. § 842(h) gives the Secretaries of
16
Indeed, the only change made to Title II was to eliminate reference to a particular
device previously approved to measure average dust concentrations. See Pub. L. 95-164, § 202
(amending section 202(e) of the Coal Act).

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Labor and HHS authority to approve respiratory equipment. Section 202(f), 30

U.S.C. § 842(f) defines the term “average concentration” of RCD, and references a

process for measurement that involves, in some measure, both Secretaries. The

details of that provision being significant to the present dispute, we shall defer our

discussion of them. Suffice it to say that the Mine Act’s intent—to draw upon

health expertise, to focus on worker safety, and to minimize conflicts generated by

federal agencies with an industry-driven mission—are clear. The precise

mechanics of the amendments and their success in achieving those goals are an

issue that we shall examine as necessary.

C. Regulatory History Following the Mine Act

Regulatory work under the Mine Act did not revisit immediately the single-

shift issue. During the early 1990s, MSHA responded “to concerns about possible

tampering with dust samples” by creating a Task Force to review the RCD

program. Mine Shift Atmospheric Conditions; Respirable Dust Sample, 63 Fed.

Reg. 5,664, 5,667 (Feb. 3, 1998). Out of that review, MSHA developed a spot

inspection program that for the first time was based upon samples taken over a

single shift or day. “Based on the data from the SIP inspections, the Task Group

concluded that MSHA’s practice of making noncompliance determinations solely

on the average of multiple-sample results did not always result in citations in

situations where miners were known to be overexposed to respirable coal mine

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dust.” Id. at 5,668. Specifically, multi-sample averaging could mask significant

overexposures. “In response to these findings, in November 1991, MSHA decided

to permanently adopt the single shift inspection policy initiated during the SIP.”

Id. Thus began a series of attempts at modifying, by administrative processes, the

multi-shift sampling regime in an effort “designed to defeat suspected tampering of

dust samples by mine operators.” Nat’l Mining Ass’n, 153 F.3d at 1266. For the

first time, in 1994, the Secretaries jointly proposed rescission of the 1972 Joint

Finding in the Federal Register. See Mine Shift Atmospheric Conditions;

Respirable Dust Sample, 59 Fed. Reg. 8,357 (Feb. 18, 1994). 17 The following

year, NIOSH issued a Criteria Document 18 recommending a move to single-shift

sampling. In 1996, an advisory committee created by the Department of Labor to

which the NIOSH recommendation had been referred also recommended

single‑shift sampling. See 30 U.S.C. §§ 811(a)(1), 812. In 1998, MSHA and

NIOSH, armed with the recommendations from NIOSH and the advisory

17
Unlike the present, comprehensive New Dust Rule, the 1994 proposal addressed only
the Joint Finding.
18
A “Criteria Document” is the mechanism by which NIOSH fulfills its statutory duty
under 30 U.S.C. § 811(a)(6)(B) to “submit to the Secretary [of Labor] all pertinent criteria
regarding any . . . substances determined to be toxic” “at the concentrations in which [they are]
used or found in a mine.”

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committee, again jointly proposed to rescind the 1972 Joint Finding, and did

rescind it after notice and comment. 19

In 1998, the National Mining Association challenged the 1998 Joint Finding

on the ground that MSHA had failed to comply with the procedural requirements

of section 101 of the Mine Act, 30 U.S.C. § 811, and, specifically, the

requirements of section 101(a)(6), 30 U.S.C. § 811(a)(6), that MSHA demonstrate

feasibility, use of the best available evidence and latest scientific data, and assure

that no miner will suffer a material health impairment. MSHA responded

principally by arguing that it was not required to follow section 101, 30 U.S.C.

§ 811, in order to rescind the Joint Finding, and even if it was, it was not required

to follow substantive directions in section 101(a)(6), 30 U.S.C. § 811(a)(6), that

were not “procedure-setting.” Nat’l Mining Ass’n, 153 F.3d at 1268. We granted

the National Mining Association’s petition and vacated the 1998 Joint Finding on

the basis that MSHA was required to meet all of the requirements of section 101,

30 U.S.C. § 811, in order to rescind the 1972 Joint Finding, but had failed to

demonstrate economic feasibility, and, therefore, the rescission was invalid. Id. at

1269.

19
Mine Shift Atmospheric Conditions; Respirable Dust Sample, 63 Fed. Reg. 5,664 (Feb.
3, 1998) (“1998 Joint Finding”). The 1994 proposal was summary in nature. The 1998 Final
Rule was a lengthy publication with the rescission of the Joint Finding as its only substantive
change, with the rest of the publication comprising supporting evidence.

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Following the National Mining decision, MSHA and NIOSH proposed

jointly to rescind the 1972 Joint Finding. See Determination of Concentration of

Respirable Coal Mine Dust, 65 Fed. Reg. 42,068 (July 7, 2000). They engaged in

notice-and-comment procedures and held public hearings. They twice reopened or

extended the period to allow further development of the record, specifically on new

technology for testing, the CPDM. The CPDM is a technology intended to replace

the testing that had been in place since the original enactment of the Coal Act in

1969, namely, the Coal Mine Dust Personal Sampler Unit (“CMDPSU”). Testing

with the CMDPSU required filters to be mailed away by operators to MSHA

facilities for testing and introduced a delay of at least a week before samples could

be processed. The CPDM, by contrast, takes continuous samples and makes them

available to the mine and MSHA in real time, thus preventing possible avenues for

tampering and enabling operators to implement additional, responsive air quality

measures on an as-needed basis.

This administrative action resulted in the promulgation of two rules. First, in

2010, following notice-and-comment procedures, MSHA promulgated new

regulations concerning standards for approval of CPDMs. See Coal Mine Dust

Sampling Devices, 75 Fed. Reg. 17,512 (Apr. 6, 2010) (codified at 30 C.F.R. part

74). Pursuant to those regulations, NIOSH approved a CPDM by Thermo Fisher

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Scientific in 2011. See 79 Fed. Reg. at 24,818.20 Consideration of the proposed

rule to rescind the 1972 Joint Finding never was completed.

Also in 2010, MSHA, acting alone, proposed the present, comprehensive

New Dust Rule. 75 Fed. Reg. 64,412. It issued an economic analysis to address

our concerns in National Mining that it had failed to determine the economic

feasibility of single-shift sampling. It also opened the record for comment and

extended the comment period three times, finally closing it in June 2011. MSHA

promulgated its final rule in 2014, with alterations made in response to the

comments received to its proposed rule. 79 Fed. Reg. 24,814.

III. MSHA’s Authority to Regulate

With this background in mind, we now turn to the precise issues presented

for our review. We first address whether MSHA acted in accordance with the

statute when it promulgated the New Dust Rule under its own authority rather than

with the joint participation of NIOSH in the promulgation process. At the outset,

we note the narrowness of this question: no one maintains that NIOSH has not

participated in, or does not agree with, the determinations made by MSHA.

Indeed, it is clear that NIOSH has been proposing many of the same revisions for

decades. As counsel for the petitioners told us at oral argument, the question here

20
See infra note 24.

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concerns only the formal process of promulgation and NIOSH’s failure to sign on

the dotted line.

A. The Statutory Provisions

In assessing the contention that the New Dust Rule is infirm simply because

of the absence of a joint promulgation by the MSHA and NIOSH, we begin with

the language of the statutory sections at issue. Section 101 of the Mine Act

provides:

The Secretary [of Labor] shall by rule in accordance with
procedures set forth in this section and in accordance with section 553
of Title 5 (without regard to any reference in such section to sections
556 and 557 of such title), develop, promulgate, and revise as may be
appropriate, improved mandatory health or safety standards for the
protection of life and prevention of injuries in coal or other mines.

30 U.S.C. § 811(a); see also Mine Act § 101(a). Its following subsections add

substantial detail, including significant substantive involvement by the Secretary of

HHS and NIOSH. They do not change, however, the basic structure of regulatory

authority and responsibility embodied in subsection (a), which indicates that they

belong to the Secretary of Labor alone.

The next section that concerns us is section 202, which provides, in pertinent

part:

(a) Samples; procedures; transmittal; notice of excess
concentration; periodic reports to Secretary [of Labor]; contents
Each operator of a coal mine shall take accurate samples of the
amount of respirable dust in the mine atmosphere to which each miner
in the active workings of such mine is exposed. Such samples shall be
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taken by any device approved by the Secretary [of Labor] and the
Secretary of [HHS] and in accordance with such methods, at such
locations, at such intervals, and in such manner as the Secretaries shall
prescribe in the Federal Register within sixty days from December 30,
1969 and from time to time thereafter. Such samples shall be
transmitted to the Secretary [of Labor] in a manner established by
him, and analyzed and recorded by him in a manner that will assure
application of the provisions of section 814(i) of this title when the
applicable limit on the concentration of respirable dust required to be
maintained under this section is exceeded. . . .

....

(d) Promulgation of new standards; procedures
Beginning six months after the operative date of this subchapter
and from time to time thereafter, the Secretary of [HHS] shall
establish, in accordance with the provisions of section 811 of this title,
a schedule reducing the average concentration of respirable dust in the
mine atmosphere during each shift to which each miner in the active
workings is exposed below the levels established in this section to a
level of personal exposure which will prevent new incidences of
respiratory disease and the further development of such disease in any
person. Such schedule shall specify the minimum time necessary to
achieve such levels taking into consideration present and future
advancements in technology to reach these levels.

(e) Concentration of respirable dust
References to concentrations of respirable dust in this
subchapter mean the average concentration of respirable dust
measured with a device approved by the Secretary [of Labor] and the
Secretary of [HHS].

(f) Average concentration
For the purpose of this subchapter, the term “average
concentration” means a determination which accurately represents the
atmospheric conditions with regard to respirable dust to which each
miner in the active workings of a mine is exposed (1) as measured,
during the 18 month period following December 30, 1969, over a
number of continuous production shifts to be determined by the
Secretary [of Labor] and the Secretary of [HHS], and (2) as measured
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thereafter, over a single shift only, unless the Secretary [of Labor] and
the Secretary of [HHS] find, in accordance with the provisions of
section 811 of this title, that such single shift measurement will not,
after applying valid statistical techniques to such measurement,
accurately represent such atmospheric conditions during such shift.

30 U.S.C. § 842; see also Mine Act § 202.

The question before us is whether these statutory provisions, read in concert,

require joint promulgation of the New Dust Rule or permit the approach taken by

MSHA in this case—joint participation in development of the substantive

standards, but promulgation by MSHA alone.

B. The Authority to Impose Single-Shift Sampling

In our previous decision, National Mining Ass’n, 153 F.3d 1264, we

examined a jointly promulgated regulation by MSHA and NIOSH in which the

agencies had tried to accomplish single-shift sampling under section 202(f), 30

U.S.C. § 842(f). At the time, the challengers claimed that MSHA had violated the

statute by failing to undertake the feasibility analysis required by section 101(a)(6),

30 U.S.C. § 811(a)(6). MSHA took the position that section 101, 30 U.S.C. § 811,

did not apply in its entirety to the joint finding in section 202, 30 U.S.C. § 842(f).

We flatly rejected this position and held, unambiguously, that to regulate on the

single-shift issue under section 202(f), 30 U.S.C. § 842(f), “MSHA must follow all

the provisions of [section 101, 30 U.S.C.] § 811.” Id. at 1268 (emphasis added);

accord Sec’y of Labor, MSHA v. Keystone Coal Mining Corp., 16 FMSHRC 6,

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12–13 (1994) (rejecting MSHA’s position that § 811 did not apply to § 842(f)).

It is clearly the law of this circuit that the transition to a single-shift

sampling regime is a matter to be promulgated by MSHA alone. In holding

squarely that this matter is governed by section 101, 30 U.S.C. § 811, National

Mining forecloses any other result. Our precedent simply precludes our accepting

the petitioners’ views that section 202(f), 30 U.S.C. § 842(f), requires, on its face,

joint promulgation, that MSHA previously has taken an alternate position on the

meaning of this provision, 21 or that what was done by two agencies should not be

allowed to be undone by one. “Stare decisis is the preferred course because it

promotes the evenhanded, predictable, and consistent development of legal

principles, fosters reliance on judicial decisions, and contributes to the actual and

perceived integrity of the judicial process.” Payne v. Tennessee, 501 U.S. 808, 827,

111 S. Ct. 2597, 2609 (1991). Moreover,

the burden borne by the party advocating the abandonment of an
established precedent is greater where [we are] asked to overrule a
point of statutory construction. Considerations of stare decisis have
special force in the area of statutory interpretation, for here, unlike in
the context of constitutional interpretation, the legislative power is
implicated, and Congress remains free to alter what we have done.

21
With respect to this particular consideration, we note the irony of the petitioners’
position, given that at least some of the petitioners in this case were the ones advocating in the
prior case for the full application of section 101, 30 U.S.C. § 811, to section 202, 30 U.S.C.
§ 842(f).

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Patterson v. McLean Credit Union, 491 U.S. 164, 172–73, 109 S. Ct. 2363, 2370

(1989), superseded in part on other grounds by statute, Civil Rights Act of 1991,

Pub. L. No. 102-166, 105 Stat. 1071; see also Halliburton Co. v. Erica P. John

Fund, Inc., ---U.S.----, 134 S. Ct. 2398, 2411 (2014).

C. The Authority to Enact Other Substantive Regulations

We next examine whether the provisions of the New Dust Rule not

addressed in section 202(f), 30 U.S.C. § 842(f) (i.e., the provisions other than the

transition to single-shift sampling) were also subject to the general promulgation

rule in section 101, 30 U.S.C. § 811 permitting promulgation by MSHA or whether

these provisions must be promulgated by the Secretaries of Labor and of HHS.

The petitioners invite our attention generally to section 202, 30 U.S.C.

§ 842. When read in isolation, that section might indeed appear somewhat

supportive of their position that a joint promulgation is required with respect to the

comprehensive dust regulation topics governed by subsections (a) and (d). Indeed,

subsection 202(a), 30 U.S.C. § 842(a), recites that “the Secretaries shall prescribe

in the Federal Register,” and section 202(d), 30 U.S.C. § 842(d) provides that “the

Secretary of [HHS] shall establish” the respective standards. Nevertheless, we

cannot accept this argument; we have confronted it in National Mining and

rejected squarely such a non-contextual reading of the entire statutory scheme.

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In National Mining, we focused on section 201 of the Mine Act, 30 U.S.C.

§ 841(a). It provides:

The provisions of sections 842 through 846 of this title and the
applicable provisions of section 878 of this title shall be interim
mandatory health standards applicable to all underground coal mines
until superseded in whole or in part by improved mandatory health
standards promulgated by the Secretary [of Labor] under the
provisions of section 811 of this title, and shall be enforced in the
same manner and to the same extent as any mandatory health standard
promulgated under the provisions of section 811 of this title. Any
orders issued in the enforcement of the interim standards set forth in
this subchapter shall be subject to review as provided in subchapter I
of this chapter.

30 U.S.C. § 841(a); see also Mine Act § 201(a). Put simply, section 201

designates sections 202 through 206 as “interim mandatory health standards” and

reinforces that their transition to “improved mandatory health standards

promulgated by the Secretary” of Labor will occur under section 101. See 30

U.S.C. §§ 811, 841, 842–846. This language matches exactly the language in

section 101, 30 U.S.C. § 811, that the Secretary bears the responsibility to

“develop, promulgate, and revise as may be appropriate, improved mandatory

health or safety standards.” See also Mine Act § 3(l), 30 U.S.C. § 802(l) (defining

interim mandatory health or safety standards as those appearing between sections

201 and 206, 30 U.S.C. §§ 841–846).

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Notably, our analysis of section 202(f), 30 U.S.C. § 842(f), in National

Mining did not turn exclusively on its cross-reference to section 101, 30 U.S.C.

§ 811. It proceeded through section 201, 30 U.S.C. § 841. We said:

Use of single-shift measurements by MSHA is a health and
safety standard. Mandatory health and safety standard is defined, in
§ 802(l) as “the interim mandatory health or safety standards”
between § 841 and § 846. Section 842(f) is the basis for single-shift
sampling. Furthermore, § 841(a) refers to §§ 842–846 as “interim
mandatory health standards.” At a minimum, therefore, § 842(f) is an
interim mandatory health standard. § 841(a) continues, however, to
say that the interim mandatory health standards of §§ 842–846 are
effective “until superseded in whole or in part by improved mandatory
health standards.” Single-shift sampling supersedes multi-shift
sampling, which was based on § 842(f). Single-shift sampling,
therefore, is an “improved mandatory health standard.” According to
§ 841(a), any new standard must be “promulgated . . . under the
provisions of Section 811.”

153 F.3d at 1267–68 (citations omitted) (emphasis in orginal). In short, National

Mining addressed not simply the proper interpretation of § 842(f), but read, as it

should, the texts of §§ 811, 841, and 842, as a coherent whole. 22 Indeed, it was by a

holistic interpretation of the statutory scheme that the court relied on the plain

22
See Meredith v. Fed. Mine Safety & Health Review Comm’n, 177 F.3d 1042, 1055
(D.C. Cir. 1999) (“[W]e next look to the text and structure of the Mine Act as a whole, and to the
dual-enforcement regime established thereby. In so doing, we follow the cardinal rule that a
statute is to be read as a whole, since the meaning of statutory language, plain or not, depends on
context. This shift in perspective is ultimately dispositive; by moving beyond the text of section
105(c) to examine the statutory scheme in which it reposes, the implausibility of the UMWA’s
proffered construction becomes undeniable.” (internal quotation marks omitted) (citations
omitted)).

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wording of the statute and did not have to proceed beyond the first step of the

Chevron analysis.

In deciding National Mining, an earlier panel of this court correctly

perceived section 201, 30 U.S.C. § 841, as the cornerstone provision for discerning

Congress’s scheme, expressed in the entire statute, for continued progress in

achieving mine safety. The panel understood that Congress designated section

202, 30 U.S.C. § 842, as a transitional health standard, intended for eventual

improvement through the mechanism of section 101, 30 U.S.C. § 811. See Mine

Act § 201, 30 U.S.C. § 841. This understanding of the statute not only supports

our interpretation of section 202(f), 30 U.S.C. § 842(f), but it also makes clear that

section 201, 30 U.S.C. § 841, is the fulcrum upon which the entire regulatory

structure of the statute turns.

The petitioners nevertheless contend that there is a direct conflict in the

statutory language, and the “specific” language of section 202, 30 U.S.C. § 842,

referring to both Secretaries controls the “general” language of sections 101 and

201, 30 U.S.C. §§ 811 and 841, designating the Secretary of Labor as the

responsible agency head. Respectfully, we believe this interpretation misconstrues

the statutory scheme. “[W]hen deciding whether the language is plain, we must

read the words ‘in their context and with a view to their place in the overall

statutory scheme.’” King v. Burwell, No. 14-114, slip op. at 9, --- U.S. ---- (2015)

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(quoting FDA v. Brown & Williamson Tobacco Corp., 529 U.S. 120, 133, 120

S. Ct. 1291, 1301 (2000)). “Our duty, after all, is ‘to construe statutes, not isolated

provisions.’” Id. (quoting Graham Cty. Soil and Water Conservation Dist. v.

United States ex rel. Wilson, 559 U.S. 280, 290, 130 S. Ct. 1396, 1404 (2010)).

Accordingly, we conclude that the Mine Act envisions precisely the

approach taken by the relevant agencies here and provides the Secretary of Labor,

acting through MSHA, with broad regulatory authority, sufficient to authorize the

New Dust Rule.

IV. Substantive Challenges: The Content of the New Dust Rule

A. Standard of Review

In addition to the procedural challenges we already have examined, the

industry plaintiffs also challenge the substance of the New Dust Rule. We review

the challenges under the Administrative Procedure Act, and shall “hold unlawful

and set aside” any agency action that is “arbitrary, capricious, an abuse of

discretion, or otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A); see

also Kennecott Greens Creek Mining Co. v. MSHA, 476 F.3d 946, 952 (D.C. Cir.

2007).23

23
For those of petitioners’ challenges based on the statutory language, our review is
structured by Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837,
104 S. Ct. 2778 (1984). When there is a statutory ambiguity, we move to its second step, which
asks whether the agency’s interpretation is “arbitrary or capricious in substance.” Mayo Found.
for Med. Educ. and Research v. United States, 562 U.S. 44, 53, 131 S. Ct. 704, 711 (2011). As
(continued . . .)
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[U]nder this standard, a reviewing court may not set aside an agency
rule that is rational, based on consideration of the relevant factors and
within the scope of the authority delegated to the agency by the
statute. . . . The scope of review under the “arbitrary and capricious”
standard is narrow and a court is not to substitute its judgment for that
of the agency. Nevertheless, the agency must examine the relevant
data and articulate a satisfactory explanation for its action including a
“rational connection between the facts found and the choice made.”

Motor Vehicle Mfrs. Ass’n v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 42–43,

103 S. Ct. 2856, 2866 (1983); accord Miami-Dade Cty. v. U.S. E.P.A., 529 F.3d

1049, 1064 (11th Cir. 2008).

Many of the challenges raised in the industry briefing invite our attention to

evidence that contradicts the conclusions drawn by MSHA, some within the record

and some external to it. They do so in large measure by invoking the statutory

requirements found in section 101(a)(6)(A) of the Mine Act, 30 U.S.C.

§ 811(a)(6)(A):

The Secretary [of Labor], 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. Development of mandatory standards under
this subsection shall be based upon research, demonstrations,

the Supreme Court has noted, this second step of Chevron is functionally equivalent to
traditional arbitrary and capricious review under the APA. Judulang v. Holder, --- U.S. ----, 132
S. Ct. 476, 483 n.7 (2011). We therefore make no distinction between the disputes over
interpretive ambiguities and more general challenges to the present regulation in our discussion.

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experiments, and such other information as may be appropriate. In
addition to the attainment of the highest degree of health and safety
protection for the miner, other considerations shall be the latest
available scientific data in the field, the feasibility of the standards,
and experience gained under this and other health and safety laws.
Whenever practicable, the mandatory health or safety standard
promulgated shall be expressed in terms of objective criteria and of
the performance desired.

Many of the specific challenges to the content of the New Dust Rule, therefore,

focus on whether MSHA considered the “best available evidence” or whether

MSHA demonstrated technological or economic feasibility of such standards.

These statutory requirements are significant, and, as the litigation history of this

regulation has shown, the failure to address them would require us to vacate the

rule. See Nat’l Mining Ass’n, 153 F.3d at 1267–69 (finding that MSHA’s failure to

abide by the requirements of § 811(a)(6)(A) in promulgating a rescission of the

1972 Joint Finding on single-shift sampling required vacatur of the rule). Before

us, however, is an extremely thorough rulemaking comprising nearly 200 pages.

All of the challenges presented were raised by the petitioners or others in the

industry as part of the comment period on the proposed rule, see Mine Act

§ 101(d), 30 U.S.C. § 811(d), (providing that “[n]o objection that has not been

urged before the Secretary [of Labor] shall be considered by the court, unless the

failure or neglect to urge such objection shall be excused for good cause shown”),

and, in the main, MSHA addressed the counter-evidence directly in stating its

conclusions in the Federal Register.
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Most importantly, the statutory requirements of section 101(a)(6)(A), 30

U.S.C. § 811(a)(6)(A), have no effect on the standard of review that we apply to

this case, which is highly deferential. We do not sit in judgment of what evidence

is indeed “best” or whether the proposed rule is “feasible” under the statute. We

ask only whether MSHA’s conclusions on these matters pass muster under the

APA. Furthermore, like our colleagues on the District of Columbia Circuit, we

believe it appropriate to “give an extreme degree of deference to the agency when

it is evaluating scientific data within its technical expertise.” Kennecott Greens

Creek Mining Co., 476 F.3d at 954 (internal quotation marks omitted); see also

Marsh v. Oregon Nat. Res. Council, 490 U.S. 360, 378, 109 S. Ct. 1851, 1861

(1989) (“When specialists express conflicting views, an agency must have

discretion to rely on the reasonable opinions of its own qualified experts even if, as

an original matter, a court might find contrary views more persuasive.”). To do

otherwise puts this court in the unenviable—and legally untenable—position of

making for itself judgments entrusted by Congress to MSHA. Finally, the Mine

Act evinces a clear bias in favor of miner health and safety. The duty to use the

best evidence and to consider feasibility are appropriately viewed through this lens

and cannot be wielded as counterweight to MSHA’s overarching role to protect the

life and health of workers in the mining industry. Not only do we decline to

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balance interests, we acknowledge that when MSHA itself weighs the evidence

before it, it does so in light of its congressional mandate.

With the standard of review firmly established and MSHA’s mandate in

mind, we now turn to the particular substantive challenges raised in the briefing.

B. Single-Shift Sampling

Prior to the effective date of the New Dust Rule under review, and consistent

with the 1972 Joint Finding favoring multi-shift averaging, the regulations

provided:

Compliance determinations are based on the average
concentration of respirable dust measured by five valid respirable dust
samples taken by the operator during five consecutive normal
production shifts or five normal production shifts worked on
consecutive days (multiple-shift samples). Compliance determinations
are also based on the average of multiple measurements taken by the
MSHA inspector over a single shift (multiple, single-shift samples) or
on the average of multiple measurements obtained for the same
occupation on multiple days (multiple-shift samples).
Under the existing program, sampling results are often not
known to mine operators, miners, and MSHA for at least a week or
more after the samples are collected. Due to the delay in receiving
sampling results, operators are unable to take timely corrective action
to lower dust levels when there are overexposures.

79 Fed. Reg. at 24,817. In the preamble to the New Dust Rule now under

review, MSHA explains the changes to the former multi-shift averaging

scheme:

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The Secretary [of Labor] has found, in accordance with sections 101
(30 U.S.C. 811) and 202(f)(2) (30 U.S.C. 842(f)(2)) of the 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. Accordingly, the 1972 Joint Finding, by
the Secretary of the Interior and the Secretary of [HEW], on the
validity of single-shift sampling is rescinded. Final § 72.800 clarifies
that MSHA will make a compliance determination based on a single
full-shift MSHA inspector sample.
In addition, final § 72.800 clarifies that noncompliance with the
respirable dust standard or the applicable respirable dust standard
when quartz is present, in accordance with subchapter O, is
demonstrated when a single, full-shift measurement taken by MSHA
meets or exceeds the applicable [excessive concentration value] . . . .
However, as explained elsewhere in this preamble under final
§ 70.208(e), under the final rule, a noncompliance determination
based on a single full-shift sample only applies to MSHA inspector
samples and not operator samples. . . .
. . .Under final § 72.800, a noncompliance determination on a
single full-shift sample is only based on an MSHA inspector’s single
full-shift sample and not an operator’s single full-shift sample.
Noncompliance based on an operator’s samples consists of either 2 or
3 operator samples (depending on where the sample is taken) or the
average of all operator samples, but not both.

79 Fed. Reg. at 24,932–33 (footnote omitted).

1. Statutory and accuracy-related challenges

At the outset of their substantive challenge to the New Dust Rule, the

petitioners question MSHA’s decision to depart from a regime of multi-shift

averaging to single-shift sampling to determine the atmospheric conditions in the

mine relative to its RCD limits. The petitioners claim that the single-shift scheme

distorts the congressional intent to limit “chronic exposure to excessive RCD, not

. . . short-term or episodic exposures.” Murray Energy Br. 29. They further
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contend that the prior multi-shift scheme “‘minimize[d] the variability associated

with the result of a single shift sample or several samples on a single shift’” and

from “‘human and mechanical error.’” Id. at 31 (quoting Am. Mining Cong. v.

Marshall, 671 F.2d 1251, 1259 (10th Cir. 1982)). By contrast, the New Dust

Rule’s focus on the dustiest locations in the mine violates the statutory directive to

determine “the atmospheric conditions . . . to which each miner . . . is exposed.”

Mine Act § 202(f), 30 U.S.C. § 842(f) (emphasis added). Consequently, they

contend, the move to single-shift sampling defies the statute’s requirement that the

RCD samples “accurately represent” the atmospheric conditions in the mine. Id.

The industry petitioners further submit that the level of “accuracy” attained by

single-shift sampling is insufficient. Indeed, they maintain that the statute permits

single-shift sampling only if it meets a dictionary definition of accuracy, i.e., “in

exact conformity to truth.” NMA Br. 29 (internal quotation marks omitted).

MSHA responds that the New Dust Rule’s approach of measuring over a

single shift will, “after applying valid statistical techniques to such measurement,

accurately represent such atmospheric conditions during such shift.” Mine Act

§ 202(f), 30 U.S.C. § 842(f). In its view, the move to single-shift sampling is the

product of reasoned decision-making because it is based on “significant

improvements in sampling technology, updated data, and comments and testimony

on previous notices” as well as “recommendations contained in both the 1995

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NIOSH Criteria Document and the 1996 Dust Advisory Committee Report.” 79

Fed. Reg. at 24,933.

We cannot accept the petitioners’ arguments. First, the petitioners are

incorrect in asserting that the statute is concerned only with chronic exposure. This

subsection, 202(f) of the Mine Act, 30 U.S.C. § 842(f), demonstrates Congress’s

recognition that cumulative exposure is the product of daily exposure. It therefore

explicitly requires an accurate measurement of the actual, real-time conditions in

the environment it is measuring—that is, the isolated shift in which the sampling

occurs. NMA’s argument that the result is a sampling scheme with “no connection

to the hazard that MSHA seeks to mitigate,” NMA Br. 37, is therefore unfounded.

Indeed, Congress intended the former multi-shift sampling scheme to accomplish

the same purpose as single-shift sampling. Under the Mine Act, the former

approach was considered a temporary accommodation until technology and

experience convinced MSHA that an accurate single-shift methodology was

feasible. The statute therefore allows multi-shift sampling only when there is a

finding that measurement during a particular shift does not accurately describe the

conditions of that particular shift. See Mine Act § 202(f), 30 U.S.C. § 842(f).

MSHA’s move to single-shift sampling is, therefore, grounded in the statute.

We also see no merit in the petitioners’ contention that the single-shift

sampling methodology of the New Dust Rule is inherently unreliable and therefore

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frustrates the purposes of the statutory scheme. In addressing the accuracy of

single-shift sampling, MSHA acknowledged in its rulemaking that “all

measurements of atmospheric conditions are susceptible to some degree of

measurement error.” 79 Fed. Reg. at 24,934. In deciding to employ NIOSH’s

Accuracy Criterion to determine the acceptability of single-shift sampling, it

selected a rule that requires samples to be within 25 percent of the actual sample 95

percent of the time. In making this decision, MSHA noted that the Accuracy

Criterion “is relevant and widely recognized and accepted in the occupational

health professions as providing acceptable limits for industrial hygiene

measurements.” Id. To support its decision, MSHA relied upon NIOSH studies,

which showed that, using either available monitoring technologies (the CPDM or

the CMDPSU), 24 single-shift sampling conforms to the Accuracy Criterion. 25

24
“Since the 1970s, mine operators and MSHA inspectors have used the
approved coal mine dust personal sampler unit (CMDPSU) to determine
the concentration of respirable dust in coal mine atmospheres.” 79 Fed. Reg. at 24,859. The
CMDPSU is a pump unit, worn or carried by the miner for 8 hours or his entire shift, whichever
is shorter. Through its internal mechanism, nonrespirable particles are removed, and respirable
dust particles are deposited on the filter surface. The collection filter is capped at the end of
sampling “and sent to MSHA for processing, where it is disassembled to remove the filter
capsule for weighing under controlled conditions to determine the amount of dust that was
collected on the filter.” Id. at 24,860. The analysis took a week or more, preventing mine
operators from putting in place effective controls when dust exceeded the applicable limits.

As described in the preamble to the present rule, the principal goal in the development of
the CPDM technology was “[t]he ability to continuously monitor and give mine operators and
miners real-time feedback on dust concentrations in the work environment.” Id. MSHA set
forth to support the development of “a new type of personal dust monitor that would provide a
direct measurement of respirable coal mine dust levels in the mine atmosphere on a real-time
(continued . . .)
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In evaluating the industry petitioners’ specific objections, we first must note

that the decision to use the Accuracy Criterion to evaluate the technology is not

properly challenged in the present case. The regulation establishing its use to

evaluate CPDM technology, 30 C.F.R. § 74.8, was not challenged within sixty

days of its promulgation in 2010, as required for this court to have jurisdiction.

See Mine Act § 101(d), 30 U.S.C. § 811(d). Even if implementation of the

basis, unlike the existing sampling system used since 1970.” Id. Unlike its predecessor, the
CPDM achieves that goal:

The CPDM is a respirable dust sampler and gravimetric analysis device
that is incorporated into the miner’s cap lamp battery case as a single package
located on the belt. The device represents the first major advance in dust sampling
technology in more than 30 years.

Respirable Coal Mine Dust: Continuous Personal Dust Monitor (CPDM), 74 Fed. Reg. 52,708,
52,709 (Oct. 14, 2009). Mechanically, the core of the device is an inertial mass sensor called the
TEOM, a hollow, tapered tube “which is clamped at the base and free to oscillate at its narrow or
free end on which the collection filter is mounted.” Id. Electronics near the tapered element
cause it to oscillate at its natural frequency when free of dust. Dust entering the device is first
filtered to remove oversized, nonrespirable particles. RCD continues to the filter mounted on the
free end of the tapered element, where it is captured. Once affixed to the filter, the particles
change the frequency of oscillation of the TEOM in direct proportion to their mass. Critically,
that change in oscillation is processed and analyzed internal to the device, and it continuously
and immediately calculates and displays:

(1) The respirable dust concentration calculated at distinct 30-minute intervals; (2)
the average respirable dust exposure from the beginning of the shift; and, (3) the
percent of exposure limit. Through the display, both the mine operator and miners
wearing the device have the ability for the first time to gauge respirable dust
exposures, as well as the effectiveness of corrective actions taken by authorized
personnel to reduce a miner’s exposure.

Id.
25
See, e.g., Appendix at V-BKG-55 at 1005, II-BKG-8 at 20.

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Accuracy Criterion were properly before us, we only would have to determine that

MSHA’s determination was a reasonable one worthy of our deference. The statute

does not require technology with a zero tolerance for error—an impossible

standard—as a prerequisite to the adoption of single-shift sampling. Indeed, it

expresses a preference for single-shift sampling. Mine Act § 202(f), 30 U.S.C.

§ 842(f) (identifying single-shift sampling as the default rule). MSHA was

justified in determining that technology that satisfies the Criterion is sufficiently

accurate to sustain a move to single-shift sampling. 26

The industry petitioners also maintain that the abandonment of multi-shift

sampling introduces an element of variability into the sampling methodology that

eviscerates the statutory command for accuracy. By implementing the new scheme

without the check provided by multi-shift sampling, reliance on samples taken

from the dustiest locations is, they contend, also unfaithful to the statutory

command to evaluate the conditions “to which each miner in the active workings

of the mine is exposed,” Mine Act § 202(f), 30 U.S.C. § 842(f). See Murray

Energy Br. 31–32. To support this argument, the petitioners invite our attention to

American Mining Congress v. Marshall, 671 F.2d 1251 (10th Cir. 1982), in which

26
The use of the Accuracy Criterion and its margin of error is not, as the petitioners
contend, an admission that the measurements taken are inaccurate. It is not a “drastic[]
re‑defin[ition],” NMA Br. 38, of the statutory term “accurately.” It is an accepted methodology,
used successfully in other occupational health contexts. 79 Fed. Reg. at 24,934.

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our colleagues on the Tenth Circuit evaluated area sampling, a program designed

to sample near dust-generating sources away from the working sections of the

mine. In their view, the court in that case approved of area sampling only because

MSHA employed multi-shift sampling. We cannot accept such an interpretation of

American Mining Congress. The petitioners in that case challenged the prior 1980

Dust Rule on numerous bases. In considering those myriad challenges, the court

did evaluate whether MSHA had sufficiently accounted for variability inherent in

the chosen sampling methodology. The court relied in part on its conclusion that a

multi-shift scheme “minimizes the variability associated with the result of a single

sample.” Id. at 1259. This case hardly stands for the proposition that multi-shift

sampling was required to account for variability. It merely states that MSHA’s

response to the “conflicting evidence” about variability, which included

persistence in the use of multi-shift sampling, was adequate to address any

variability issues. Id. Indeed, the court’s remaining analysis undercuts any claim

that it was a necessary response. In soundly rejecting the petitioners’ suggestion

that citations should not issue when the measurements were within the range of

sampling error from the statutory standard, the court stated that such a rule

would resolve the remaining variability solely in favor of mine
operators, to the detriment of the congressional purpose to protect
miners from black lung disease. Congress has not mandated any
accounting for variability and has given the Secretary broad
discretion in enforcing the respirable dust standard. The Secretary

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has not abused his discretion by refusing to put the risk of the
remaining error on miners.

Id. (emphasis added). Moreover, this discussion of potential issues with variability

was entirely separate from the section addressing new additions to the existing

sampling program, which found that MSHA’s judgment in favor of area sampling

was reasonable despite the fact that it might overestimate a given miner’s

exposure:

The Secretary has demonstrated a rational basis for the designated
area sampling program: if the atmosphere in the area of a known dust
generation source is in compliance with the statutory standard, then it
can safely be assumed that all miners are protected from overexposure
to respirable dust. This assumption is justified since no one individual
constantly works next to an outby[ 27] dust generation source over the
course of an entire shift.
Id. at 1256.

Sampling in the dustiest locations 28 is and has been the applicable rule for

decades and cannot seriously be challenged here. In any event, even when

considered in conjunction with a new single-shift sampling scheme, we must

conclude that MSHA has supplied for its action a reasoned basis consistent with

27
The program under review in the Tenth Circuit case included not simply designated
occupation sampling, but a new “designated area sampling program in the non-working sections
of the mine,” specifically, a program that responded to “studies showing that dust generated by
sources outby (away from) the working face poses a significant health hazard to miners.” Am.
Mining Cong. v. Marshall, 671 F.2d 1251, 1254 (10th Cir. 1982) (internal quotation marks
omitted).
28
See supra note 3; see also Am. Mining Cong., 671 F.2d 1251.

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congressional intent. In the context of the present rulemaking, MSHA has

responded that the dustiest locations are indeed areas where miners work and

where they travel, and that all miners are thereby protected from excessive

concentrations. MSHA’s response to comments submitted during the rulemaking

reads, in relevant part:

While area sampling does not show a particular miner’s dust
exposure, the area sampling results will show whether miners are
exposed to excessive dust concentrations. The objective of area
sampling is to control the concentration of respirable dust to which
miners are exposed in the workplace. In American Mining Congress v.
Secretary of Labor, 671 F.2d 1251 (10th Cir. 1982), the Court found
that area sampling was reasonable and consistent with the Mine Act.

If placed in a fixed location, the CPDM will provide an accurate
measurement of the respirable dust in the atmosphere where miners
work or travel. In addition, it will provide immediate information to
the miners working in that location so that the mine operator could
make immediate adjustments in controls in relation to dust sources to
reduce dust generation or suppress, dilute, divert, or capture the
generated dust. Compared with administrative controls or respirators,
well-designed engineering controls provide consistent and reliable
protection to all workers because the controls are less dependent on
individual human performance, supervision, or intervention to
function as intended. Area sampling with the CPDM will also provide
information on miners’ exposure in areas with the highest
concentration of dust. This will give the mine operator and MSHA
valuable data to pinpoint areas in need of improvement.

79 Fed. Reg. at 24,886.

In light of the congressional purpose and the lack of any statutory command

to the contrary, it is permissible for MSHA to select a sampling scheme that

resolves ambiguities in dust levels resulting from sampling issues in favor of
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miners’ health, even if it results in a scheme that is more aggressive in its demands

on the industry. See Am. Mining Cong., 671 F.2d at 1256. MSHA’s conclusions

on this issue are reasoned, take into account prior court decisions, and serve the

practical purpose of allowing immediate corrective measures in mine trouble-spots.

2. Feasibility of single-shift sampling

The petitioners next assert that MSHA failed to demonstrate that its move to

single-shift sampling is technologically feasible. See NMA Br. 34–39. All of these

arguments can be reduced to a simple assertion by the petitioners that single-shift

sampling produces inaccurate results and will burden the industry with faulty data

suggesting overexposure. We already have rejected the petitioners’ challenge to

the extent that it rests on adoption of the Accuracy Criterion and do not repeat that

analysis here. With respect to the remainder of the “accuracy”-related challenges

to single-shift sampling, MSHA readily acknowledges that there is significant

variability in coal dust concentration at places in the mine, and there are

measurement differences that occur depending on the placement of the sampling

device on the miner’s body, his orientation with respect to dust-producing

activities, and the like. If the device encounters different levels of respirable dust,

the miner himself encounters variable concentrations of RCD as well.29

29
The National Mining petitioners also claim that, through its adoption of ECVs, MSHA
“recognizes the error” in single-shift sampling and attempts to compensate for it with “limited”
(continued . . .)
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There is neither a “perfect” or “true” concentration of dust in a particular

area of the mine, nor is there is a perfect sampling method. See Am. Mining Cong.,

671 F.2d at 1256 (“[M]easurement error is inherent in all sampling, [so] the very

fact that Congress authorized a sampling program indicates that it intended some

error to be tolerated in the enforcement of the dust standard.”); see also id. (“Since

there is no perfect sampling method, the Secretary has discretion to adopt any

sampling method that approximates exposure with reasonable accuracy. The

Secretary is not required to impose an arguably superior sampling method as long

as the one he imposes is reasonably calculated to prevent excessive exposure to

respirable dust.”). MSHA’s rule reflects knowledge of this imperfection, as well as

a detailed understanding of improvements—both technological and in the

standards for collection by operators—that make single-shift sampling sufficiently

“accurate” as to satisfy the statutory standard. See 79 Fed. Reg. at 24,935–36.30

but statistically insufficient “increases in applicable exposure limits.” NMA Br. 38–39. MSHA
responds that the ECVs are intended to compensate for inaccuracies inherent in any
measurement, regardless of whether it is from a single or multiple shifts or using the older or
newer device. See MSHA Br. 50–51.
30
The National Mining petitioners also state that “MSHA dared not base its feasibility
analysis on single-shift measurements,” but “tried to support its rule with hypotheticals and
analysis of averages that smooth over the variability of underlying single-shift samples. MSHA’s
analysis averaged thousands of historical sample results, smoothing out inaccurate peak results.”
NMA Br. 37 (emphasis in original) (citations omitted). But this claim is belied by the very
analysis that they cite in the preamble, in which MSHA states that, “[a]lthough some
commenters” had claimed the feasibility analysis was based exclusively on “historical averages,”
it was instead based on “the mean (or average) concentrations, the average deviation of sample
(continued . . .)
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C. Technological Feasibility of Other Major Provisions of the New Dust
Rule

The petitioners next raise a host of other feasibility challenges. Before

addressing each of these, we call to mind the counsel of the Supreme Court when it

interpreted a nearly identical provision of the OSH Act. On that occasion, the

Supreme Court noted that when a statute commands that the agency consider the

feasibility of its regulations, the bar should not be set prohibitively high: “feasible

means capable of being done, executed, or effected.” Am. Textile Mfrs. Inst., Inc.,

v. Donovan, 452 U.S. 490, 508–09, 101 S. Ct. 2478, 2490 (1981) (internal

quotation marks omitted). A feasibility determination decidedly does not require

the agency to engage in a cost-benefit analysis. Where the statute directs the

agency to assure employee safety “to the extent feasible,” “Congress itself defined

the basic relationship between costs and benefits, by placing the ‘benefit’ of

worker health above all other considerations save those making attainment of this

‘benefit’ unachievable.” See id. at 509, 101 S. Ct. at 2490. Our colleagues in the

District of Columbia Circuit similarly have said,

[g]iven that feasibility determinations involve complex judgments
about science and technology, our standard of review is deferential:

concentrations from standards, and the percentage of observations above the standard.” 79 Fed.
Reg. at 24,868 (emphasis added). That is, it is not the case that MSHA proceeded with averages
to “smooth over,” NMA Br. 37, the variability—MSHA explicitly used averages, along with the
magnitude and frequency of variations in its calculations.

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the agency is not obliged to provide detailed solutions to every
engineering problem, but only to give plausible reasons for its belief
that the industry will be able to solve those problems in the time
remaining.

Kennecott Greens Creek Mining Co., 476 F.3d at 957 (internal quotation marks

omitted). With this approach in mind, we now turn to the petitioners’ specific

objections.

1. Mandatory use of the CPDM

Petitioners assert that the transition to the CPDM is not feasible. They

contend that MSHA ignored record evidence of the device’s high malfunction rate,

failed to consider that its measurement methodology does not protect against

inaccuracies due to oversized particles which are not respirable, failed to consider

that it is not capable of silica measurement, used inaccurate assumptions to

calculate its availability timeline to the industry, and reached incorrect conclusions

about the ability of miners to wear the device without impeding their work. Each

of these objections was raised before MSHA during the comment period of the

rulemaking process, and MSHA responded to them on the merits in the preamble

of the final rule. As we have noted earlier, in our review, we do not reweigh the

evidence before MSHA; we simply assess whether MSHA’s position, in light of

the evidence before it, meets a threshold of reason such that it cannot be deemed

arbitrary. See Motor Vehicle Mfrs. Ass’n, 463 U.S. at 43, 103 S. Ct. at 2866 (“The

scope of review under the ‘arbitrary and capricious’ standard is narrow and a court
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is not to substitute its judgment for that of the agency.”); id. at 43, 103 S. Ct. at

2866–67 (noting that the reviewing court must determine whether “the agency . . .

examine[d] the relevant data and articulate[d] a satisfactory explanation for its

action including a rational connection between the facts found and the choice

made” rather than exhibiting “a clear error of judgment” (internal quotation marks

omitted)).

We also note that, although the petitioners have questioned whether NIOSH

had the requisite degree of formal involvement in the rulemaking process required

by the statute, see supra section III (evaluating claims that HHS must co-

promulgate rules), they cannot seriously challenge that MSHA acted consistently

with the advice of NIOSH when making its substantive determinations. Indeed,

NIOSH was directly involved both in the prior rulemaking on the CPDM

technology and the actual, currently marketed commercial CPDM device. See

generally 75 Fed. Reg. 17,512; see supra pp. 30–31. Moreover, in the course of

the present rulemaking, NIOSH’s comments on the CPDM, included in the record,

responded directly to many of the objections raised by the petitioners in their

comments on the proposed rule. With this consideration in mind, we now turn to

petitioners’ specific objections.

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a. Accuracy challenges to the CPDM

The petitioners assert that the devices fail to satisfy the NIOSH Accuracy

Criterion more than 40 percent of the time. NIOSH reviewed the data relied on by

petitioners on this issue and noted that its source was a single mine operator and

that it was based on only 955 individual measurements. By contrast, NIOSH’s

own data “analyzed samples that were statistically representative of the nation’s

underground coal mining industry” and had been “collected by MSHA inspectors

at approximately 20 percent of active mechanized mining units.” 79 Fed. Reg. at

24,863. NIOSH’s comparison of the data sets, accepted by MSHA, notes that

“[s]tatistically representative samples are critical for correctly estimating the bias

of the CPDM relative to the gravimetric method of the CMDPSU. Bias may not be

properly estimated from studies conducted in a limited number of mines or regions,

regardless of the number of samples obtained.” Id.

Moreover, the objection is based on the errant use of the Accuracy Criterion

to evaluate field samples, as opposed to laboratory testing of devices—the purpose

for which the Criterion was designed and its use intended. In field sample testing,

“[t]he variability reported by the commenter was primarily due to large sample

variability, which was due to uncontrolled variables known to exist in field

samples, even when two identical samplers were placed side-by-side.” Id. Among

the causes of that variability were “significant dust gradients known to exist,

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sampler inlet location differences, and the nature of mine ventilation.” Id. These

are real-time variations in the dust measured that can be controlled in laboratory

testing. The error of using field tests to assess device accuracy is laid plain by this

data: the complained variations are not evidence of imprecise or unreproducible

measurements due to characteristics of the device; they are actual variations in

conditions, which are variable inch by inch in a mine. Viewed in this light, the

petitioners are objecting to variability inherent in a sampling regime of any kind—

a position flatly rejected by a statute that requires a sampling program. MSHA

summarized its position on these varying analyses when it concluded, “[t]hrough

years of work, NIOSH has demonstrated that the CPDM is an accurate instrument

that meets the NIOSH Accuracy Criterion and, therefore, can be used as a

compliance instrument.” Id. 31

31
Relatedly, NMA objects that “the CPDMs not only produce results that vary
significantly from the current sampler, but they also produce highly variable results from unit to
unit.” NMA Br. 41. NMA provides only a general citation, without specificity, to a forty-nine-
page analysis by the NMA itself entitled “Analysis of MSHA Coal Dust Sampling Data Base
[sic] & The Impact Of The MSHA Proposed Rule,” see I-COMM-58-9. It is not our role to
review it independently to determine if anything contained in it supports the stated proposition.
This material was in the record before MSHA. As we already have noted, MSHA did not abuse
its discretion in relying on NIOSH studies that demonstrate the accuracy of the device under
appropriate testing conditions.

The petitioners also claim that MSHA attempted to justify the accuracy based on
averages of samples taken with the two devices. See NMA Br. at 41–42. But the cited portions
of the preamble do not support this statement. Instead, after indicating that the averages from the
devices were nearly identical, MSHA continues “that there was no statistically significant
difference between the data sets, and that the bias between” the two devices “is zero.” 79 Fed.
Reg. at 24,863 (emphasis added). It goes on to explain the mathematical analysis of the data sets
in lognormal distribution and notes that “a simple arithmetic average cannot be calculated,” so
(continued . . .)
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b. Assumptions underlying MSHA data and requests to
supplement the record before the court

In a somewhat related challenge, the petitioners claim that, because of the

variability present in sampling, operators would be required to “overengineer” their

mines to ensure against sampling readings that, because of measurement

inaccuracy, reflect noncompliance. Murray Br. 43. They contend that MSHA’s

data is based on a faulty assumption that the mines will only make the reductions

necessary to achieve compliance, but will go no further. Accordingly, they

contend that the data underlying the feasibility is itself skewed in MSHA’s favor.

The petitioners’ analysis is based, in substantial part, on materials that were

not before MSHA; they urge us, nevertheless, to take judicial notice of them.

“[T]he general rule, applicable across the board to judicial review of administrative

action . . . is that the court may not go outside the administrative record.” Najjar v.

Ashcroft, 257 F.3d 1262, 1278 (11th Cir. 2001) (internal quotation marks omitted).

Accordingly, “[w]hen directly reviewing an agency decision or regulation, a court

does not consider any evidence that was not in the record before the agency at the

time that it made the decision or promulgated the regulation.” United States v.

Guthrie, 50 F.3d 936, 944 (11th Cir. 1995). Though “certain circumstances may

“[t]he appropriate method is to average the logarithms of the numbers, followed by un-
transformation of the logarithmic averages” and so on. Id.

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justify going beyond the administrative record,” we are “not generally empowered

to do so.” See Preserve Endangered Areas of Cobb’s History, Inc. v. United States

Army Corps of Eng’rs, 87 F.3d 1242, 1246 (11th Cir. 1996) (internal quotation

marks omitted). We have acknowledged that various factors could be considered

in determining the propriety of reviewing extra-record material on review of an

agency rule, id. at 1246 n.1; in practice, however, we generally have focused

pointedly on whether the petitioners have made “a strong showing of bad faith or

improper behavior by the agency.” See Alabama-Tombigbee Rivers Coalition v.

Kempthorne, 477 F.3d 1250, 1262 (11th Cir. 2007) (internal quotation marks

omitted). Because we conclude that the allegations of “bad faith” made by the

petitioners in their submissions are not supported,32 we deny the motion for judicial

notice and confine our substantive review to the record as it stood before MSHA. 33

32
Murray Energy’s allegation of bad faith is based principally on MSHA’s failure to
reference the findings of a 1996 study it commissioned on the development of a fixed-site,
machine-mounted sampling device. Murray Energy contends that MSHA made an improper
assumption in its calculations, and this 1996 study provides the data that undermines the
assumption. Regardless of the value of the data included in that study, Murray Energy’s
objection to MSHA’s failure to include it cannot reasonably support expansion of the record
here. The assumption to which Murray Energy refers was plainly stated in the materials
accompanying the proposed rule as well as the final rule, and there is simply no persuasive
justification for allowing the petitioners to rest now on a decades-old study, available to them
during notice-and-comment, on which they failed to rely.
33
We note that NMA has made a separate motion for judicial notice of a host of
documents. Many of them are legal authorities, and with respect to these we note that the
procedural vehicle of a motion is unnecessary; we can and do take account of all relevant
authorities in determining the content of the law. NMA also submits, however, substantive
evidentiary materials, including a study commissioned for Kentucky’s state-level energy agency,
an affidavit filed in support of the brief which provides further analysis of sampling data, and a
(continued . . .)
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We further note, in any event, that MSHA has persuasively demonstrated that the

assumption with which the petitioners take issue was made in the context of, and

confined to, an entirely separate conclusion—whether the rule will achieve the

intended health benefits for miners—not the issue of feasibility on which the

petitioners’ argument is based. Accordingly, we see no basis in this objection to

find MSHA’s action to have been arbitrary.

c. Malfunction rate of the CPDM

The petitioners also submit that CPDMs have a high malfunction rate, with

35 percent of units requiring a return to the manufacturer for repair, and 12 percent

returned more than once. After examining the data submitted by the petitioners,

NIOSH responded that the data lacked “an appropriate experimental protocol to

control” critical variables and reflected a misunderstanding by operators of the

comment from the Chamber of Commerce in a separate rulemaking proceeding. With respect to
these factual materials, NMA asserts that their consideration is necessary to ensure that MSHA
considered all relevant material in formulating its rule. See Preserve Endangered Areas of
Cobb’s History, Inc. v. United States Army Corps of Eng’rs, 87 F.3d 1242, 1246 (11th Cir.
1996). Whatever the outer limits of this exception to the general rule that review is on the
administrative record alone, it is plainly not an invitation to leave the record open indefinitely.
The gravamen of NMA’s request is to place before us materials not raised during agency
proceedings on the justification that MSHA did not, in a complete notice-and-comment
rulemaking, reference, on its own initiative, additional materials that potentially could undermine
its position. We do not require MSHA to demonstrate the absence of any additional relevant
materials in order to set about the task of regulating required of it by Congress. If this material
supported the petitioners’ position below, they had an obligation to present it.

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import of “error” messages. 79 Fed. Reg. at 24,863–64. MSHA describes

NIOSH’s response to the data clearly:

[T]hese commenters misunderstood the CPDM error messages
received during their testing, believing that the messages indicated
failure of the CPDM. The CPDM, as currently programmed, monitors
its performance during sampling and registers any status conditions
(errors) logged during the sample run. These messages are not
indicative of a failure of the CPDM, rather they provide the user with
valuable constructive feedback in real-time concerning sample
validity. The frequency and type of these error messages are logged
during sample collection. They will be used by MSHA to determine
whether samples are valid or should be voided.

Id.

In response, in its brief, NMA states that MSHA’s explanation, that “error”

is a status code, rather than an indication of device failure, “does nothing to change

the fact that CPDMs appear to malfunction 200 out of every 1,000 times.” NMA

Br. 42. But that is exactly what MSHA’s explanation resolves. The error codes do

not indicate failure, therefore, failure rates based on error codes are per se invalid.

To the extent that NMA is arguing that the devices give the appearance of failure,

MSHA’s explanation should suffice to assure operators that they are not, indeed,

failing.

MSHA further noted that “[g]iven the limited data set, including error

messages, from only five mines cited by the commenters as evidence of CPDM

failure, both NIOSH and MSHA consider the cited failure rate of 41 errors per

1,000 hours to be invalid. The NIOSH published data remains the most
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appropriate data set to assess the failure rate of the CPDM.” 79 Fed. Reg. at

24,864. According to that data, the failure rate was lower by “an order of

magnitude,” at only 4.75 per 1,000 hours. Id. Moreover, repair rates had

improved quarter-to-quarter since the devices were first used in mine settings, and

“repair rates are expected to improve in general due to the quality control systems

required for certification” of the devices as well as “the actions taken by the

manufacturer to address reported field performance.” Id. Before this court, the

petitioners simply restate the data that they provided to MSHA in their comments,

without addressing any of MSHA’s reasons for rejecting that data in favor of the

published results of NIOSH studies. Accordingly, the petitioners ask us to reweigh

the evidence, an option that is simply not available to us under our narrow standard

of review.

The petitioners also contend that later laboratory analysis of samples was a

critical “analytical safeguard[] against inaccurate measurements,” including those

caused by oversized, non-respirable coal dust. NMA Br. 43. MSHA

unapologetically abandoned later analysis in favor of real-time analysis for

multiple reasoned bases, including the value of real-time information in employing

secondary air-quality controls and the elimination of the possibility of operator

tampering. Moreover, the device’s internal controls allow for the same safeguards,

in part by issuing status (formerly “error”) codes to indicate oversized particles,

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etc. The petitioners cite no evidence that these internal device protections against

measurement of oversized particles are insufficient to correct the issue they

identify.

d. Performance at varying temperatures and humidities

The petitioners next object that data showed that the CPDM became

inaccurate at high temperatures and humidities. MSHA rejected this data. The

preamble noted that “[t]he differences” cited by the commenter “are below the

minimum detection limit of the commercial CPDM . . . . Therefore, the

commenter’s conclusions, which are based on these test results, are inaccurate.”

Id. at 24,864. Moreover, it was unclear whether the commenter had used the

“user-selected temperature operating range to optimize performance,” and without

that information, the validity of the data could not be assessed. Id. Further, the

objecting commenter had used an “outdated” Department of Defense testing

procedure “not designed to evaluate the accuracy and precision of airborne dust

sampling instruments.” Id. Finally, the testing involved talc as a proxy for RCD,

which MSHA states is “not representative of respirable coal mine dust.” Id.

Again, the petitioners’ brief does not endeavor to undermine MSHA’s reasons for

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rejecting the data, instead simply citing the data and claiming that MSHA

“disregarded [the] evidence.” NMA Br. 41. 34

On all of these questions regarding the implementation of the CPDM device,

the record simply does not support the petitioners’ assertion that MSHA

“disregarded evidence” in reaching its conclusions about the CPDM’s accuracy.

Instead, MSHA’s conclusions, which essentially echo NIOSH’s statistically valid

analyses, address head-on the contrary data and explain the flaws that make it less

than trustworthy. Its conclusions are supported both by data and by reasoned

explanations that the petitioners have failed to challenge in substance. More to the

point, the petitioners’ arguments relying on their previously submitted data, with

no attempt to address the deficiencies in it identified by MSHA, provide us with no

reasoned basis for finding that MSHA acted in excess of its broad statutory

discretion.

34
The petitioners also assert failure of the CPDM because of certain electromagnetic
interference. However, MSHA asserts that the commercial CPDM satisfies the existing
standards for interference set in 30 C.F.R. § 74.7(f). Further, MSHA stated in the preamble that
additional standards regarding radio frequency and electro-static discharge interference will be
incorporated into part 74, the CPDM has been redesigned to satisfy those new standards, and
independent lab testing will confirm it before its use is mandatory. See 79 Fed. Reg. at 24,864–
65. We must conclude that MSHA has taken note of the interference objection and acted within
its discretion to address it.

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e. CPDM as an impediment to miner’s ability to perform
work

The petitioners also object that use of the device is not feasible because

miners cannot wear the device “without impeding their ability to perform their

work safely and effectively.” See NMA Br. 45 n.10 (quoting 30 C.F.R. § 74.7(a)).

MSHA responds that the petitioners’ analyses are based on the pre-commercial

model, and NIOSH’s own analysis of the improved commercial model reaches

opposite conclusions, including that the device “adds no more than eight ounces to

the total weight carried by the miner.” MSHA Br. 59 (citing 79 Fed. Reg. at

24,866). MSHA also cites planned ergonomic improvement from the

manufacturer, including the possible reduction of weight. Id. It also notes that,

although the proposed rule required continuous monitoring, the New Dust Rule

requires only fifteen samples on consecutive normal production shifts per quarter.

Accordingly, the petitioners have not come forward with data that demonstrates a

performance issue when the device, in its current commercial iteration, is worn on

the more limited schedule prescribed in the New Dust Rule.

f. Availability of the CPDM

The petitioners next object that the device will not be available in time for

implementation of the rule in February 2016. NMA claims that MSHA “entirely

failed to consider” the availability issue, and therefore its implementation schedule

is arbitrary and capricious. NMA Br. 46 (internal quotation marks omitted).
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However, again, the record does not support this assertion. MSHA asserts that it

developed the eighteen-month phase-in in consultation with the manufacturer, but

noted that

if MSHA determines that there are logistical or feasibility issues
concerning availability of the CPDM, MSHA will publish a notice in
the Federal Register to continue to use an approved CMDPSU to
conduct quarterly sampling. In addition, assuming no technological
issues arise concerning the use and manufacture of CPDMs, and
depending on manufacturer projections, if CPDMs are not available in
sufficient quantities, MSHA will accept, as good faith evidence of
compliance with the final rule, a valid, bona fide, written purchase
order with a firm delivery date for the CPDMs.

79 Fed. Reg. at 24,884. Not only has MSHA considered availability and given a

timeline based on available evidence, it also already has developed a contingency

plan. We have no basis for finding this approach to the question arbitrary.

2. The silica standards35

Shifting their focus from the CPDM, the petitioners challenge whether

MSHA has demonstrated the feasibility of what they claim are new silica PEL

(permissible exposure limit) and silica-based, reduced RCD limits. See NMA Br.

46. MSHA points out, however, that the new rule does not establish any new silica

35
The regulations use the term “quartz,” although the parties’ briefs generally prefer the
term “silica.” According to MSHA’s website, “The terms ‘crystalline silica’ and ‘quartz’ refer to
the same thing. Quartz is a natural constituent of the earth’s crust and is not chemically
combined with any other substance.” MSHA, MSHA’s Occupational Illness and Injury
Prevention Program, Health Topic: Silica Exposure of Surface Coal Miners,
http://www.msha.gov/illness_prevention/healthtopics/hhicc01.htm (last visited December 27,
2015). For the sake of consistency, we shall adopt the parties’ terminology.

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PEL. See 79 Fed. Reg. at 24,866, 24,882. Instead, it states that its new rule merely

applies the rule of existing 30 C.F.R. § 70.101, which has consistently limited a

miner’s total exposure to respirable silica to 0.1 mg/m3. Under the existing rule,

this limit was achieved principally by a requirement that the mine atmosphere

contain less than 5% silica (because 5% of 2.0 mg/m3—the existing overall RCD

limit—is 0.1 mg/m3). When, under the existing rule, the mine atmosphere

contained greater than 5% silica, the overall RCD limit was reduced in proportion

to the silica content such that the resulting RCD limit assured a total exposure less

than the 0.1 mg/m3 limit. The new rule maintains the identical limit on respirable

silica of 0.1 mg/m3, but because of the new RCD limits and their variations, 36 the

rule is now phrased in terms of the 0.1 mg/m3 limit rather than the 5% threshold. 37

36
The overall RCD limits imposed by the rule are somewhat generically expressed as 1.5
mg/m3, but are actually variable to a degree based on certain conditions. For example, in the
case of a miner who has evidence of CWP, the rules require that operators allow him to work
only in a mine atmosphere where the RCD concentration is, beginning August 1, 2016, no higher
than 0.5 mg/m3. See 30 C.F.R. § 90.100(b). Likewise, the same lower standard applies,
beginning in August 2016, “within 200 feet outby the working faces of each section in the intake
airways.” 30 C.F.R. § 70.100(b)(2).
37
The existing rule states:

When the respirable dust in the mine atmosphere of the active workings
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 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 § 70.206 (Approved sampling devices; equivalent
concentrations), computed by dividing the percent of quartz into the number 10.

(continued . . .)
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Accordingly, MSHA has a reasoned basis for concluding that the silica standard

does not create a new limit.

The petitioners also object to the silica standard on feasibility, given that the

new CPDM device does not measure silica. However, it is worth emphasizing that

neither the newer CPDM nor the prior CMDPSU are capable of silica

measurements in RCD. Neither of those devices is designed for that function.

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).

30 C.F.R. § 70.101 (2013). New 30 C.F.R. § 70.101 states:

(a) Each operator shall continuously maintain the average concentration of
respirable quartz dust in the mine atmosphere during each shift to which each
miner in the active workings of each mine is exposed at or below 0.1 mg/m3 (100
micrograms per cubic meter or μg/m3) as measured with an approved sampling
device and expressed in terms of an equivalent concentration.

(b) When the equivalent concentration of respirable quartz dust exceeds
100 μg/m3, 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 as measured with an approved sampling device
and expressed in terms of an equivalent concentration at or below the applicable
dust standard. The applicable dust standard is computed by dividing the percent of
quartz into the number 10. The application of this formula shall not result in an
applicable dust standard that exceeds the standard established by § 70.100(a).

EXAMPLE: Assume the sampled MMU or DA is on a 1.5-mg/m3 dust
standard. Suppose a valid representative dust sample with an equivalent
concentration of 1.12 mg/m3 contains 12.3% of quartz dust, which corresponds to
a quartz concentration of 138 μg/m3. Therefore, the average concentration of
respirable dust in the mine atmosphere associated with that MMU or DA shall be
maintained on each shift at or below 0.8 mg/m3 (10/12.3% = 0.8 mg/m3).

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Nevertheless, as the foregoing discussion makes clear, existing rules also set silica

limits, enforceable in essentially the same manner. Without a presently approved

device capable of direct, real-time measurement of the silica content of RCD,

MSHA has elected to reduce the potential health impact of high-silica RCD with a

proxy measure: MSHA collects samples itself, with its own equipment, to

determine a percentage of silica specific to a particular mine’s atmosphere. When

the level of silica in a mine’s atmosphere crosses a threshold set by the rule

(indeed, this threshold remains unchanged from prior regulations), MSHA uses a

simple calculation that reduces the overall RCD limit below the generally

applicable limits in direct proportion to the silica content it has observed. MSHA

has identified further, and perhaps more direct, silica limits as a potential subject to

be addressed in a future rulemaking. See 79 Fed. Reg. at 24,882. Even if the

amendments to the rule were broad enough to give us jurisdiction over a challenge

to a procedure that has been in effect for years—a doubtful proposition, at best—

the history demonstrates the reasonableness of MSHA’s current approach.38

38
The petitioners fare no better with their objections based on rock dust, which is added
to the mine environment and used to control combustibility within the mines. Existing standards
limit the RCD and silica content of rock dust, and it is not clear how an operator meeting those
standards would have further difficulty imposed in combination with the New Dust Rule.

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3. The cumulative effect of the New Dust Rule’s changes

Finally, the petitioners claim that MSHA failed to conduct a feasibility

analysis that examined the cumulative effects of the proposed changes. MSHA

responds that it considered extensive data from 2008–09, adjusted to reflect the

new, more stringent definition of a normal production shift, in determining the

ability of operators to meet the new standards. On the basis of these actual RCD

measurements, MSHA concluded that the probability of compliance with the new

standards was extremely high, for some areas already at 90%, and even in the very

dustiest areas at 65%. It then examined each and every sample in excess of the

new standard and determined on a case-by-case basis whether the operator had

utilized existing controls, finding that they had not “[i]n each instance.” MSHA

Br. 64; see also 79 Fed. Reg. at 24,869 (“MSHA reviewed measurements of the

engineering controls in use on the day each sample was collected to assess whether

using additional engineering controls would have likely reduced the dust

concentration to levels at or below 1.5 mg/m3. Every survey indicated that

additional control measures are available that would be likely to reduce the

respirable dust concentration to 1.5 mg/m3 or less.” (emphases added)).39 This data

analysis is simply not the “brush off,” Murray Energy Br. 39, that the petitioners
39
Moreover, MSHA’s data examined only whether the samples would have satisfied the
RCD standard itself, without giving operators the additional benefit of the ECV table and its
accounting for a margin of sampling error. See infra p. 78 & note 40.

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claim. The petitioners merely ask us to reweigh the evidentiary record and credit

their submissions that further use of existing engineering controls is not possible.

D. Economic Feasibility

The petitioners also contend that MSHA did not adequately evaluate the

economic feasibility of the New Dust Rule. In their view, MSHA grossly

underestimated the costs to the industry of compliance. NMA’s rather cursory

discussion of this topic basically suggests that the failure of MSHA’s feasibility

analysis is its failure to account for the costs to the industry associated with its

projected noncompliance with the new regime, specifically, “extensive revenue

losses from delayed production” caused by corrective actions or the necessity of

new mine plan approvals, “estimated at least at $1.6 billion per year.” NMA Br.

51. Initially, we note that Murray Energy’s assertion that MSHA’s economic

feasibility analysis comprises “just four paragraphs,” Murray Energy Br. 55,

ignores MSHA’s more than 200-page separate regulatory economic analysis. See

I-REA-16. Moreover, the substance of Murray Energy’s economic feasibility

argument is based heavily on evidence submitted to MSHA in response to the

proposed rule, specifically, a study by Dr. Robin Cantor that challenged MSHA’s

preliminary regulatory economic analysis. See I-COMM-76-1. Murray Energy

acknowledges that MSHA “appropriately responded to some of [its] critiques” in

its final rule by altering some of its proposals, Murray Energy Br. 55, but believes

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that MSHA failed to address the most significant critique, which relates to the

costs of disruptions to normal operation to implement corrective measures.

There can be no question that MSHA was required to evaluate economic

feasibility of the New Dust Rule. In our review of this rule’s predecessor, we said

so emphatically. Nat’l Mining Ass’n, 153 F.3d at 1269. As the petitioners and

MSHA agree, MSHA must “provide a reasonable assessment of the likely range of

costs of its standard, and the likely effects of those costs on the industry, so as to

demonstrate a reasonable likelihood that those costs will not threaten the existence

or the competitive structure of an industry.” Color Pigments Mfrs. Ass’n v. OSHA,

16 F.3d 1157, 1163 (11th Cir. 1994) (emphasis omitted) (internal quotation marks

omitted); see also Nat’l Mining Ass’n, 153 F.3d at 1268 & n.5 (noting that

rulemaking under the Mine Act requires an economic feasibility analysis

analogous to that required in OSHA rulemakings). After reviewing the record,

including the extensive economic analysis undertaken by MSHA and the critique

of that analysis submitted by the petitioners, we must conclude that MSHA has

fulfilled its responsibility and was entitled to make the conclusions that it did.

As a preliminary matter, to the extent that the petitioners’ arguments rely on

their view that the Rule is not technologically feasible, those arguments are

undercut by our earlier conclusion that MSHA is on solid ground with respect to

the technological feasibility of operators to achieve compliance.

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Turning to the matter of actual costs, we think that the record adequately

supports MSHA’s determination that the costs of compliance, while not

insignificant, can hardly be characterized as so high as to threaten the existence or

the competitive structure of the industry. At the outset, as the petitioners admit,

MSHA certainly was not unreasonable in discounting the industry’s analysis to the

extent that it did not account for the significant changes made by MSHA to the

final rule that improved feasibility and reduced the potential for noncompliance: an

overall reduction in the number of required samples, an alteration in the RCD limit

initially proposed of 1.0 mg/m3 limit to the 1.5 mg/m3 limit actually adopted, and

the introduction of “excessive concentration values” or ECVs.40 There remains, no

doubt, a difference of opinion between the industry and MSHA about the costs

associated with making the adjustments necessary to remedy violations, especially

those that require the repair or replacement of faulty equipment. But such

40
Excessive concentration values (ECVs) are the RCD levels, applicable to
operator‑collected samples, at which corrective action must be taken. They are greater than the
actual RCD limits, and are the result of a calculation by MSHA that grafts on to the RCD
standard, to the benefit of operators, an acknowledgement of the possibility of measurement
error. As stated in the preamble,

MSHA constructed the ECVs to ensure that a citation is issued when the
respirable dust standard is exceeded. The ECVs ensure that MSHA is 95 percent
confident that the applicable respirable dust standard has been exceeded. Each
ECV accounts for the margin of error between the true dust concentration
measurement and the observed dust concentration measurement when using the
CMDPSU or the CPDM.

79 Fed. Reg. at 24,868; see also supra pp. 6–7 & note 2.

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differences of opinion are hardly fatal to the Rule. As long as MSHA considers, as

it has, the concerns of the industry and has supplied a reasoned view as to why it

prefers the view of its own experts, we cannot hold that its decision is arbitrary and

capricious. See Fla. Manufactured Hous. Ass’n, Inc. v. Cisneros, 53 F.3d 1565,

1580 (11th Cir. 1995) (holding that an agency “is entitled to rely on the cost

estimates calculated by its own engineering staff rather than the figures submitted

by the industry’s trade association,” where “our review of the record does not

indicate that the agency’s projections are either flawed or unreasonable”). Here,

MSHA has reasoned that most such repairs and replacements will be made while

the shift continues, during the interim between shifts or during repair shifts.

I‑REA-16 at 88–89 (Regulatory Economic Analysis). It also has implicitly

recognized that, in the event of a work stoppage to correct a violation, the operator

bears the more limited cost of delayed production, but not the loss of its asset,

because the coal remains to be mined. Finally, MSHA has noted specifically that,

in determining the appropriate time frame for undertaking remedial work, the word

“immediate” is somewhat fluid. Certain controls can and should be exercised

instantaneously—such as the use of additional ventilation or water, while others

can be undertaken but not completed immediately—such as the ordering of a part.

In all these matters, MSHA gives due consideration to the good faith of the

operator. Id. at 88 (noting that some actions can occur before the next shift, but

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others, such as those requiring a part to be obtained, will satisfy the “immediate

corrective action” requirement with a bona fide purchase order).

MSHA has addressed adequately the economic feasibility of the New Dust

Rule.

E. Other Challenges

The petitioners raise several additional brief objections, including a claimed

failure of MSHA to consider the “best available evidence” and the experience of

other agencies in implementing other health and safety laws. See Mine Act

§ 101(a)(6)(A), 30 U.S.C. § 811(a)(6)(A).

1. National regulation

Murray Energy begins with a best-available-evidence claim that the rule

irrationally regulates nationally when the incidence of CWP has lessened

nationwide and has spiked only regionally. In its view, the latest scientific

evidence supports the view that silica is more toxic than ordinary RCD and that

cases of silicosis caused by silica exposure are mischaracterized as rapidly

progressing CWP. On this point, the scope of disagreement between the parties is

narrower than the petitioners suggest. There is no dispute that silica is a dangerous

substance; indeed, the rule (as in prior rules) reduces the maximum RCD limits in

proportion to a high presence of silica dust in a particular mine environment. The

parties also agree that silica has the potential to advance the progression of CWP

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and to cause its own serious lung disease, silicosis. The petitioners contend,

however, that the evidence demonstrates that the rise in CWP upon which the New

Dust Rule is predicated is really a rise in silicosis, or perhaps a rise in a subtype of

CWP in which silica is the principal factor. They claim that MSHA ignored the

scientific evidence on this point.

On the contrary, MSHA devotes several pages of the preamble to addressing

objections regarding RCD concentration as a predictor of CWP rates, see 79 Fed.

Reg. at 24,823, localized spikes in CWP rates, id. at 24,827–28, effects of silica on

CWP and data regarding silicosis, id. at 24,828–29, and other factors influencing

CWP rates, such as the variable carbon content of coal at certain mines, id. at

24,829. After reviewing the evidence cited by the petitioners as well as other

evidence, MSHA concludes:

Based on all of the available evidence, MSHA believes that respirable
coal mine dust has a fibrogenic effect on the development of CWP in
coal miners independent of the quartz or silica content of the coal.
High silica content may accelerate the progression of CWP to PMF
[progressive massive fibrosis], the most severe form of CWP, but
there is no evidence to suggest that the presence of silica is a
necessary condition for CWP, PMF, severe emphysema, or
[non‑malignant respiratory disease] mortality.

Id. at 24,829–30. The record contains a wealth of not-always consistent research

on this issue, and MSHA does not cite each paper or author on which the

petitioners relied in their responses. Nevertheless, MSHA acknowledged the

petitioners’ concern and their data, presented contrary evidence that supported
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MSHA’s position, and reached a conclusion about the appropriate course based on

that evidence.

The petitioners submit that MSHA merely rejected strawmen and failed to

address its objections that CWP was declining and silicosis was, as a matter of

epidemiology, the likelier culprit for present-day areas of concern. We cannot

accept the petitioners’ contentions for two reasons: First, MSHA’s conclusion that

CWP rates can improve further with further reductions to the RCD limits is a

reasoned one, supported by the historical record and the data before MSHA in the

present rulemaking. Accordingly, the petitioners’ assertion that “CWP is declining

under the current system, i.e., the system is working,” Murray Energy Br. 64, even

if true, is irrelevant where CWP incidence has not been reduced to zero and MSHA

has not completely fulfilled its mission to “protect the health . . . of the Nation’s

coal or other miners.” Mine Act § 2(g), 30 U.S.C. § 801(g); see also id. § 2(c), 30

U.S.C. § 801(c) (noting the urgent need to “prevent,” not merely reduce the

incidence of, “occupational diseases originating in . . . mines”); id. § 101(a)(6)(A),

30 U.S.C. § 811(a)(6)(A) (“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

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capacity even if such miner has regular exposure to the hazards dealt with by such

standard for the period of his working life.” (emphasis added)).

Secondly, MSHA’s evaluation of the silica question is a paradigmatic

example of an agency “evaluating scientific data within its technical expertise” to

which “an extreme degree of deference to the agency” is appropriate. Kennecott

Greens Creek Mining Co., 476 F.3d at 954–55. Moreover, to the extent the

petitioners’ objection is focused on a regulatory need to address silicosis, not only

do we defer to an agency’s determination of regulatory priorities, we must

acknowledge that MSHA has identified silica content in RCD as a subject for

potential future rulemaking. See id. at 954 (finding it reasonable for the agency to

regulate in an area of known risks and continue researching further potential risks).

2. Use of respirators to achieve air quality standards

Next, the petitioners contend that MSHA should have accepted their

proposal to allow operators to satisfy the RCD standards with the use of secondary

personal controls—principally, personal respirators. MSHA counters that the

statute does not permit this approach. We agree; the statute is unambiguous on this

point: “Use of respirators shall not be substituted for environmental control

measures in the active workings.” Mine Act § 202(h), 30 U.S.C. § 842(h). The

petitioners nevertheless claim that the statute, which only prohibits

“substitut[ion],” allows respirators to be used in conjunction with other controls, as

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a secondary measure. MSHA does not dispute this proposition, and, indeed,

acknowledges that the New Dust Rule requires operators to provide respirators

under certain conditions, specifically, where an operator-collected sample exceeds

the ECV. See 30 C.F.R. §§ 70.208(e)(1), 72.700. Therefore, nothing in the rule

prevents the industry from employing respirators as part of a hierarchy of controls

that should be used together as “the best way to ensure miner safety and health,”

NMA Br. 58. MSHA has interpreted the statutory command correctly, however, in

requiring that mine air quality meet the regulatory standard without resort to a

personal control.

3. Experience under other health and safety laws

Finally, the petitioners claim that MSHA has failed to consider “experience

gained under this and other health and safety laws.” Mine Act § 101(a)(6)(A), 30

U.S.C. § 811(a)(6)(A). In support of this claim, however, the petitioners cite only

that other health and safety laws exist. Not only are these other standards cited

without any context to show that they are based on the latest technology and latest

health information, they are unaccompanied by data that demonstrate their success

in achieving the goal of eliminating CWP. 41

41
Additionally, we acknowledge that, in the hundreds of pages of briefing submitted in
this case, the petitioners have raised additional arguments challenging the rule. We have not
addressed arguments that were insubstantial either because they lacked any legal or evidentiary
support or because they were plainly without merit.

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Conclusion

MSHA acted consistently with its statutory authority in promulgating the

New Dust Rule; the statute, read as a whole, clearly delegates regulatory authority

for the matters covered by the New Dust Rule to its authority alone. Substantively,

MSHA’s decisions comport with the requirements of the statute and are not

otherwise arbitrary, capricious, or an abuse of discretion. Accordingly, we deny

the petitions for review.

PETITIONS DENIED.

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