 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued October 10, 2019                Decided May 15, 2020

                        No. 18-1282

            KIEWIT POWER CONSTRUCTORS CO.,
                      PETITIONER

                              v.

    SECRETARY OF LABOR, U.S. DEPARTMENT OF LABOR,
                    RESPONDENT


                 Consolidated with 18-1317


        On Petitions for Review of a Final Order of
   the Occupational Safety & Health Review Commission


    Scott Glabman, Senior Appellate Attorney, U.S.
Department of Labor, argued the cause for petitioner Secretary
of Labor. With him on the briefs were Edmund C. Baird,
Associate Solicitor for Occupational Safety and Health, and
Charles F. James, Counsel for Appellate Litigation. Brian A.
Broecker and Louise M. Betts, Attorneys, entered appearances.

     Victoria L. Bor and Esmeralda Aguilar were on the brief
for amicus curiae North America's Building Trades Unions in
support of petitioner, Secretary of Labor, U.S. Department of
Labor, seeking reversal of OSHRC’s final order.
                               2
   Arthur G. Sapper argued the cause for respondent Kiewit
Power Constructors Co. With him on the briefs were John F.
Martin and Melissa A. Bailey.

    Bradford T. Hammock was on the brief for amicus curiae
National Association of Home Builders in support of Kiewit
Power Constructors Co. seeking affirmance of OSHRC’s final
order.

    Before: HENDERSON, GRIFFITH and MILLETT, Circuit
Judges.

    Opinion for the Court filed by Circuit Judge HENDERSON.

     KAREN LECRAFT HENDERSON, Circuit Judge: The
Occupational Safety and Health Act of 1970 (OSH Act), 29
U.S.C. §§ 651 et seq., directs the Secretary (Secretary) of the
United States Department of Labor (DOL) to issue safety and
health standards for the protection of American workers, id.
§ 651(b)(3). To expedite the development of national
regulations, section 6(a) authorized the Secretary, for two years
after the OSH Act’s enactment, to promulgate then-current
federal safety standards without regard to formal rulemaking
procedures. Id. § 655(a). Relevant here, 41 C.F.R. § 50-
204.6(c), which requires quick-drenching eyewash facilities
for workers exposed to corrosive materials, was among the
many preexisting standards adopted pursuant to this limited
rulemaking exemption. See 29 C.F.R. § 1910.151(c). Pre-1971,
§ 50-204.6 had applied only to manufacturers and suppliers
working under federal contracts but, after its adoption under
the OSH Act, the Secretary began to enforce the quick-
drenching provision against employers in other industries,
including construction. In 1993, without notice and comment,
the quick-drenching provision was formally designated as a
construction safety standard. See 29 C.F.R. § 1926.50(g).
                              3
     In 2011 the Occupational Safety and Health
Administration (OSHA) cited Kiewit Power Constructors Co.
(Kiewit) for a “serious” violation of § 1926.50(g). Kiewit
contested the citation, arguing that the quick-drenching
provision was invalidly applied to the construction industry
without notice-and-comment rulemaking. An administrative
law judge (ALJ) agreed, Kiewit Power Constructors Co., No.
11-2395 (OSHRC Dec. 24, 2012) (ALJ) [hereinafter ALJ
Decision], as did the Occupational Safety and Health Review
Commission (OSHRC or Commission), Kiewit Power
Constructors Co., 27 BNA OSHC 1445 (No. 11-2395, 2018)
[hereinafter OSHRC Decision]. The Commission vacated
Kiewit’s citation but declined to issue a declaratory order
declaring § 1926.50(g)’s invalidity. The Secretary and Kiewit
cross-petitioned for review. Because we conclude that the
Secretary’s interpretation of the OSH Act is reasonable and
therefore entitled to deference from the Commission, we grant
the Secretary’s petition for review, deny Kiewit’s and reverse
the Commission’s decision.

                              I.

                             A.

     The OSH Act established a comprehensive regulatory
scheme “to assure so far as possible every working man and
woman in the Nation safe and healthful working conditions.”
29 U.S.C. § 651(b). Until then, workplace safety was addressed
in a patchwork manner by federal and state regulations and, to
a degree, employers’ voluntary efforts. See S. Rep. No. 91-
1282, at 3–4 (1970). The measures were largely ineffective. In
the four years preceding the Act’s adoption, more Americans
were killed at work than in the Vietnam War and the increasing
human and economic cost of industrial hazards became a
matter of serious national concern. See id. at 2.
                                 4
     A key deficiency of then-existing federal protections was
that they did not extend to all employers. For example, safety
standards promulgated pursuant to the Walsh-Healey Public
Contracts Act of 1936, 49 Stat. 2036 (codified as amended at
41 U.S.C. §§ 6501–6511), applied only to manufacturers and
suppliers operating under federal contracts, see 41 U.S.C.
§ 6502(4). Other labor laws similarly conditioned coverage on
the existence of a federal nexus. The Contract Work Hours and
Safety Standards Act, 76 Stat. 357, amended by—and
popularly referred to as—the Construction Safety Act of 1969
(CSA), Pub. L. No. 91-54, 83 Stat. 96 (codified as amended at
40 U.S.C. § 3704), authorizes the regulation of contractors and
subcontractors working on federally funded construction
projects, see 40 U.S.C. § 3704(a)(1). These circumscribed
scopes meant that, in a given industry, many workers remained
unprotected even as others were covered by applicable federal
standards.

     The OSH Act aimed to close this coverage gap by
facilitating the development of “uniformly applied” standards,
S. Rep. No. 91-1282, at 1, to cover all “businesses affecting
interstate commerce,” 29 U.S.C. § 651(b)(3). The Secretary
was therefore “authoriz[ed] . . . to set mandatory occupational
safety and health standards,” id., that “require[] conditions, or
the adoption or use of one or more practices, means, methods,
operations, or processes, reasonably necessary or appropriate
to provide safe or healthful employment and places of
employment,” id. § 652(8).1 The primary mechanism for
establishing occupational safety and health (OSH) standards
was set out in section 6(b), which requires the Secretary to

    1
        “The Secretary has delegated this [standard-promulgation]
responsibility to the Assistant Secretary for Occupational Safety and
Health,” who heads OSHA. S.G. Loewendick & Sons, Inc. v. Reich,
70 F.3d 1291, 1292 (D.C. Cir. 1995) (citing Martin v. Occupational
Safety & Health Review Comm’n, 499 U.S. 144, 147 n.1 (1991)).
                                   5
“promulgate, modify, or revoke” any OSH standard in
accordance with notice-and-comment rulemaking procedures.
Id. § 655(b).

     Alternatively, section 6(a) provided an expedited, albeit
temporary, path for the issuance of standards. Although
existing protective measures had failed to abate industrial risk
adequately, there remained value in “establish[ing] as rapidly
as possible national occupational safety and health standards
with which industry is familiar.” S. Rep. No. 91-1282, at 6.
Thus, for a two-year period following the OSH Act’s effective
date, the Secretary was to, “as soon as practicable” and
“[w]ithout regard to” the rulemaking procedures in section 6(b)
or the Administrative Procedure Act (APA), 5 U.S.C. §§ 500
et seq., promulgate as an OSH standard “any national
consensus standard, and any established Federal standard,
unless he determines that the promulgation of such a standard
would not result in improved safety or health for specifically
designated employees,” 29 U.S.C. § 655(a). A “national
consensus standard” is one “adopted and promulgated by a
nationally recognized standards-producing organization,”
following certain procedural safeguards. Id. § 652(9).2 An




    2
        In particular, a “national consensus standard”:

         (1) . . . has been adopted and promulgated . . . under
         procedures whereby it can be determined by the
         Secretary that persons interested and affected by the
         scope or provisions of the standard have reached
         substantial agreement on its adoption, (2) was
         formulated in a manner which afforded an
         opportunity for diverse views to be considered and
         (3) has been designated as such a standard by the
                                  6
“established Federal standard,” by comparison, is “any
operative occupational safety and health standard established
by any agency of the United States . . . or contained in any Act
of Congress” as of the OSH Act’s enactment. Id. § 652(10).

     The Secretary soon invoked his section 6(a) authority and,
excused from formal rulemaking, adopted scores of national
consensus and established Federal standards as OSH standards.
See National Consensus Standards and Established Federal
Standards, 36 Fed. Reg. 10,466 (May 29, 1971). Part 1910 was
added to Title 29 of the Code of Federal Regulations to house
the new OSH standards. Id. Not all established Federal
standards, however, were adopted into Part 1910 in the same
manner. The CSA standards codified in Part 19263—
promulgated a mere eleven days before the OSH Act’s
effective date—were incorporated by reference in Subpart B.
See id. at 10,469 (adopting 29 C.F.R. § 1910.12). These new
OSH standards remained tethered to the CSA standards
“prescribed in [P]art 1926[,] . . . apply[ing] . . . according to the
provisions thereof,” although coverage was extended “to every
employment and place of employment of every employee
engaged in construction work.” 29 C.F.R. § 1910.12(a).
Subpart B also incorporated by reference standards issued
pursuant to the Longshoremen’s and Harbor Workers’
Compensation Act (LHWCA), 44 Stat. 1424 (1927) (codified
as amended at 33 U.S.C. §§ 901 et seq.), which covers

        Secretary, after consultation with other appropriate
        Federal agencies.

29 U.S.C. § 652(9).
     3
       The CSA standards were originally codified at Part 1518, see
Safety and Health Regulations for Construction, 36 Fed. Reg. 7340
(Apr. 17, 1971), but, for ease of reference, we refer to their current
designation at Part 1926, see Redesignation, 36 Fed. Reg. 25,232
(Dec. 30, 1971).
                                  7
employers operating on the navigable waters of the United
States, 33 U.S.C. §§ 902(4), 941; see National Consensus
Standards and Established Federal Standards, 36 Fed. Reg. at
10,469 (adopting 29 C.F.R. §§ 1910.13–1910.16).

     The Walsh-Healey standards, however, were given new
designations elsewhere in Part 1910. Relevant here, Walsh-
Healey’s “quick-drenching” eyewash standard, 41 C.F.R. § 50-
204.6(c), was recodified at 29 C.F.R. § 1910.151(c), see
National Consensus Standards and Established Federal
Standards, 36 Fed. Reg. at 10,601.4 Although promulgation as
distinct Part 1910 standards suggested that the original Walsh-
Healey standards were to have a broader scope than those first
promulgated under the CSA and LHWCA, their reach was far
from clear. On the one hand, § 1910.5(c)(2) seemed to
contemplate that the general standards in Part 1910, i.e., those
derived from Walsh-Healey standards, were meant to fill in
regulatory gaps left by particular standards, like the
construction standards prescribed in Subpart B. See 29 C.F.R.
§ 1910.5(c)(2) (“[A]ny standard shall apply according to its
terms to any employment and place of employment in any
industry, even though particular standards are also prescribed
for the industry, . . . to the extent that none of such particular
standards applies.”) (emphasis added). On the other hand,
§ 1910.5(e) appeared to foreclose such a broad application,
declaring that any OSH standard derived from a Walsh-Healey
standard “is intended to apply to manufacturing or supply
operations which would be subject to the Walsh-Healey Public
Contracts Act if there were a Federal contract . . . involved.”
National Consensus Standards and Established Federal


     4
        “Where the eyes or body of any person may be exposed to
injurious corrosive materials, suitable facilities for quick drenching
or flushing of the eyes and body shall be provided within the work
area for immediate emergency use.” 29 C.F.R. § 1910.151(c).
                               8
Standards, 36 Fed. Reg. at 10,468 (adopting 29 C.F.R.
§ 1910.5(e)).

     Any confusion was eliminated, however, when OSHA
revoked § 1910.5(e) on September 9, 1971, a little over three
months after the OSH standards were promulgated. See
Applicability of Some Established Federal Standards, 36 Fed.
Reg. 18,080, 18,081 (Sept. 9, 1971). OSHA once again invoked
section 6(a) to bypass rulemaking procedures, id., claiming
additional authority under 29 C.F.R. § 1910.4(b), which
authorized OSHA to “modify or revoke” any Part 1910
standard for the full two-year period provided by section 6(a).
Although the published notice is short on reasoning, the
revocation’s stated purpose was “to remove the limitation to
the application of the standards so that they may apply to every
employment and place of employment exposed to the hazards
covered by the standards.” Applicability of Some Established
Federal Standards, 36 Fed. Reg. at 18,081.

     Nevertheless, questions remained as to whether—and to
what extent—the construction industry was subject to the
general industry standards. The Subcommittee on Editing Part
1910 for Construction Operations was convened in January
1974 to consider which general standards “may be applicable
to construction operations,” Notice of Subcommittee Meeting,
39 Fed. Reg. 861 (Jan. 3, 1974), but it failed to resolve the
lingering uncertainty. Years later, in February 1979, OSHA
responded to petitions from “both labor and management
within the construction industry . . . to develop a single set of
OSHA regulations for the exclusive use of that industry.”
Identification of General Industry Safety and Health Standards
(29 CFR Part 1910) Applicable to Construction Work, 44 Fed.
Reg. 8577 (Feb. 9, 1979). To consolidate the standards
applicable to construction companies, OSHA republished Part
1926 along with the general industry standards “identified as
                                  9
applicable to construction work,” id., including the quick-
drenching provision, id. at 8589. OSHA’s action was not a
“permanent recodification,” however, and merely “provide[d]
a better public understanding and awareness of OSHA’s
enforcement policy regarding hazards in construction.” Id. at
8577.

     Although OSHA intermittently continued to issue
guidance on applicable construction standards, it was not until
June 30, 1993, that it formally designated applicable Part 1910
standards as Part 1926 standards. See Incorporation of General
Industry Safety and Health Standards Applicable to
Construction Work, 58 Fed. Reg. 35,076 (June 30, 1993). The
quick-drenching provision thereby became a construction
standard and received its own Part 1926 designation, at
§ 1926.50(g). Id. at 35,084, 35,305. And, once again, OSHA
followed neither APA nor OSH Act rulemaking procedures,
having determined the redesignations “do[] not affect the
substantive requirements or coverage of the standards
themselves” and “do[] not modify or revoke existing rights or
obligations, []or . . . establish new ones.” Id. at 35,077.

                                 B.

     Kiewit constructs power plants and related generation
facilities across North America. On August 3, 2011, OSHA
visited Kiewit’s worksite in Rogersville, Tennessee. It cited
Kiewit for a “serious” violation5 of 29 C.F.R. § 1926.50(g)
because “employees were exposed to eye and skin burns when


5
   A “serious” violation exists “if there is a substantial probability
that death or serious physical harm could result from” the workplace
hazard, “unless the employer did not, and could not with the exercise
of reasonable diligence, know of the presence of the violation.” 29
U.S.C. § 666(k).
                                10
quick drenching facilities were not available.” J.A. 14.6 OSHA
required Kiewit to abate the violation and proposed a civil
penalty of $3,400. Id. Kiewit timely contested the citation.

     The OSH Act allocates regulatory tasks between two
distinct administrative actors. Whereas the Secretary is
“responsib[le] for setting and enforcing workplace health and
safety standards,” the Commission “is assigned to ‘carr[y] out
adjudicatory functions.’” Martin v. Occupational Safety &
Health Review Comm’n, 499 U.S. 144, 147 (1991) (second
alteration in original) (quoting 29 U.S.C. § 651(b)). Thus, the
Secretary, through his OSHA inspectors, issues citations,
including the one charging Kiewit. After “an employer notifies
the Secretary that he intends to contest a citation,” the
Commission must provide an opportunity for an evidentiary
hearing and “shall thereafter issue an order, based on findings
of fact, affirming, modifying, or vacating the Secretary’s
citation or proposed penalty.” 29 U.S.C. § 659(c). “Initial
decisions are made by an [ALJ], whose ruling becomes the
order of the Commission unless the Commission grants
discretionary review.” Martin, 499 U.S. at 148 (citing 29
U.S.C. § 661(j)).

    Before the ALJ, Kiewit filed a Motion to Dismiss or for
Summary Judgment, asserting that § 1926.50(g) was invalidly
promulgated without notice and comment; it also sought a
declaratory order affirming the same. OSHRC Decision at
1446 n.1; ALJ Decision at 1. The ALJ granted the motion to
dismiss, deeming the 1993 recodification of the quick-
drenching provision a substantive change that could be
accomplished only through rulemaking. ALJ Decision at 9–10.
After vacating the citation, the ALJ found it unnecessary to
decide Kiewit’s motion for a declaratory order. Id. at 1–2, 10.
    6
       Kiewit was also cited for two non-serious violations but did
not contest them. See J.A. 15.
                               11
Both the Secretary and Kiewit petitioned the Commission for
discretionary review. The Secretary challenged the vacatur of
his citation and Kiewit argued that it was entitled to a
declaratory order.

     The Commission vacated the citation on September 28,
2018, over the dissent of one Commissioner. OSHRC Decision
at 1446. Despite reaching the same result as the ALJ, the
Commission followed a different path. Framing the issue as
whether section 6(a) authorized the Secretary to adopt an
established Federal standard—in this case, the Walsh-Healey
quick-drenching provision—as an OSH standard and, without
notice-and-comment rulemaking, broaden its scope to include
industries not covered by the source standard, the Commission
found “the 1993 codification . . . irrelevant in that regard.” Id.
at 1448 & n.6. In other words, if the quick-drenching provision
already applied to the construction industry by virtue of earlier
OSHA action, namely, the 1993 action merely formalized
matters. The validity of § 1926.50(g) therefore turned on
whether, back in 1971, OSHA’s extension of a Walsh-Healey
standard to the construction industry exceeded the scope of the
rulemaking authority conferred by section 6(a).

     The Commission determined that “section 6(a) . . . is
silent as to whether the Secretary may apply ‘any established
Federal standard’ adopted ‘as an occupational safety or health
standard’ to industries beyond those the original standard
covered” and “[t]he Secretary concede[d] as much.” Id. at
1448. Despite section 6(a)’s silence, the Commission
nevertheless concluded that the Secretary’s interpretation of his
authority thereunder was not entitled to Chevron deference.
                                12
     First, it viewed the promulgation of § 1910.5(e)7 as
evidence that the Secretary “initially interpreted section 6(a) as
precluding him from expanding the scope of established
federal standards to other industries.” Id. at 1449. His
“complete about-face”—revoking § 1910.5(e) a mere three
months later—lacked a reasoned explanation and was therefore
arbitrary and capricious and undeserving of deference. Id. at
1449–50 (citing Encino Motorcars, LLC v. Navarro, 136 S. Ct.
2117, 2125–26 (2016)).

     The Secretary’s interpretation was “also unreasonable in
light of the language of [section 6(a)], its statutory context, and
the statutory history.” Id. at 1450 (citing Gen. Motors Corp. v.
Ruckelshaus, 742 F.2d 1561, 1570 (D.C. Cir. 1984)). Section
6(a) did not authorize substantive changes to preexisting
standards—a point the Secretary does not dispute. Id. at 1451.
Seeing no distinction between a standard’s protective terms and
its scope, the Commission concluded that extending an
established Federal standard to a new industry effected a
substantive change and was therefore impermissible. Id. The
Secretary’s interpretation would, contrary to congressional
intent, subject employers to standards without first giving them
an opportunity to provide input and, moreover, would create
“absurdities” by applying standards without regard to the
nuances of a given employment setting. Id. at 1450–51.

     Finally, the Secretary’s reliance on Commission and
circuit court precedent proved unavailing, as the Commission
distinguished Bechtel Power Co., 4 BNA OSHC 1005 (No.
5064, 1976), aff’d, 548 F.2d 248 (8th Cir. 1977), and American
Can Co., 10 BNA OSHC 1305 (Nos. 76-5162, 77-773, 78-

    7
        To refresh recall, § 1910.5(e) limited the application of
standards originally promulgated under the Walsh-Healey Act to
places of employment that would have been subject to the Walsh-
Healey Act if a federal contract were involved.
                                 13
4478, 1982), and similarly found Diebold, Inc. v. Marshall, 585
F.2d 1327 (6th Cir. 1978), and Lee Way Motor Freight, Inc. v.
Secretary of Labor, 511 F.2d 864 (10th Cir. 1975), inapposite,
see OSHRC Decision at 1454.

     In sum, the Commission vacated Kiewit’s serious
violation because § 1926.50(g) “was invalidly promulgated as
a construction standard” inasmuch as “the Secretary lacked
authority to expand the scope of the [Walsh-Healey] quick-
drenching standard and apply [it] to the construction industry
without notice-and-comment rulemaking.” Id. However, the
majority deemed Kiewit’s claim that a declaratory order “might
‘coerce’ the Secretary into deleting the cited provision from
Part 1926” too speculative. Id. at 1446 n.1. Commissioner
Attwood dissented, finding that section 6(a) plainly authorized
the Secretary to extend standards to new industries and,
alternatively, that even assuming the statutory text’s ambiguity,
the Secretary’s interpretation was reasonable and entitled to
Chevron deference. Id. at 1454–55 (Attwood, Comm’r,
dissenting).

     Kiewit petitioned for review in our court, challenging the
Commission’s order insofar as it declined to grant Kiewit’s
requested declaratory order. The Secretary petitioned for
review in the Tenth Circuit, see 29 U.S.C. § 660(a) (authorizing
petition to be filed in court of appeals for circuit where
employer has principal office), which Circuit transferred the
matter to us, see 28 U.S.C. § 2112(a)(5) (“If proceedings are
instituted in two or more courts of appeals with respect to the
same order, . . . [a]ll courts . . . shall transfer those proceedings
to the court in which the record is so filed.”). The Secretary
argues that his interpretation is reasonable and therefore
entitled to Chevron deference and, further, that the
Commission’s decision is arbitrary and capricious because it
departs from precedent without a reasoned explanation.
                                14
                                II.

     “We begin, of course, with our jurisdiction.” Capitol
Sprinkler Inspection, Inc. v. Guest Servs., Inc., 630 F.3d 217,
221 (D.C. Cir. 2011). Under OSH Act section 6(f), “[a]ny
person who may be adversely affected by a[n OSH] standard”
can seek pre-enforcement judicial review of the standard’s
validity “at any time prior to the sixtieth day after such standard
is promulgated.” 29 U.S.C. § 655(f). Although section 6(f)
“would be the exclusive method for obtaining pre-enforcement
judicial review of a standard, the provision does not foreclose
an employer from challenging the validity of a standard during
an enforcement proceeding.” S. Rep. No. 91-1282, at 8. In
addition, section 11(a) provides that judicial review of an
enforcement proceeding may be had by “[a]ny person
adversely affected or aggrieved by an order of the
Commission.” 29 U.S.C. § 660(a).

     It was not initially apparent how these provisions
interacted because “[s]ection 6(f) is silent concerning its
preclusive effect on post pre-enforcement judicial review of
section 6(a) regulations.” Deering Milliken, Inc. v.
Occupational Safety & Health Review Comm’n, 630 F.2d
1094, 1099 (5th Cir. 1980). The question, then, was whether
procedural challenges could be raised at any time or only
during the sixty-day pre-enforcement review period set out in
section 6(f). See id. at 1097–98. In some circuits, only
substantive validity claims could be considered in an
enforcement proceeding, see, e.g., Advance Bronze, Inc. v.
Dole, 917 F.2d 944, 951–52 (6th Cir. 1990); Nat’l Indus.
Constructors, Inc. v. Occupational Safety & Health Review
Comm’n, 583 F.2d 1048, 1052–53 (8th Cir. 1978); others
permitted both substantive and procedural challenges, see, e.g.,
Marshall v. Union Oil Co. of Cal., 616 F.2d 1113, 1117–18
(9th Cir. 1980); Deering Milliken, 630 F.2d at 1099. We
                               15
adopted the latter approach in Simplex Time Recorder Co. v.
Secretary of Labor, 766 F.2d 575 (D.C. Cir. 1985), concluding
“that Congress intended review of the validity of section 6
standards to be available in enforcement proceedings before the
Commission, and that Congress drew no distinction between
procedural and substantive challenges in this regard,” id. at 583
n.2. Thus, under Simplex, Kiewit’s procedural challenge to the
quick-drenching provision “would likely be allowed.” OSHRC
Decision at 1454 n.1 (Attwood, Comm’r, dissenting).

     The Secretary failed to contest the timeliness of Kiewit’s
challenge before the Commission, id., and the parties do not
dispute our jurisdiction under 29 U.S.C. § 660, see Sec’y’s Br.
1; Kiewit Br 1. Even so, the jurisdictional question is one “the
court is bound to ask and answer for itself, even when not
otherwise suggested, and without respect to the relation of the
parties to it.” Steel Co. v. Citizens for a Better Env’t, 523 U.S.
83, 94 (1998) (quoting Great S. Fire Proof Hotel Co. v. Jones,
177 U.S. 449, 453 (1900)). We ex mero motu ordered
supplemental briefing to address whether Simplex remained
good law following JEM Broadcasting Co. v. FCC, 22 F.3d
320 (D.C. Cir. 1994), which held that “challenges to the
procedural lineage of agency regulations, whether raised by
direct appeal . . . or as a defense to an agency enforcement
proceeding, will not be entertained outside the 60-day period
provided by” the Hobbs Act, id. at 325. We later applied JEM
to analogous review provisions in other statutes, confirming
that “procedural attacks on a rule’s adoption are barred even
when it is applied.” Indep. Cmty. Bankers of Am. v. Bd. of
Governors of the Fed. Reserve Sys., 195 F.3d 28, 34 (D.C. Cir.
1999) (Bank Holding Company Act). The question is whether
JEM and its progeny foreclosed what Simplex endorsed: the
raising of an otherwise untimely procedural challenge in an
enforcement proceeding.
                                16
     We conclude that Simplex remains binding precedent and,
accordingly, we have jurisdiction of this petition. Granted,
JEM and later decisions have strictly construed statutory
limitation      periods,    emphasizing       the    Congress’s
“determin[ation] that the agency’s interest generally lies in
prompt review of agency regulations.” JEM, 22 F.3d at 325
(quoting Mountain States Tel. & Tel. Co. v. FCC, 939 F.2d
1035, 1040 (D.C. Cir. 1991)). But the fact that generalized
principles of finality may bar untimely procedural attacks
under other statutes says nothing about the viability of such a
challenge under the OSH Act. Although we have differentiated
between procedural and substantive validity in other contexts,
we have not expressly rejected Simplex’s conclusions and the
JEM line of precedent has not addressed the OSH Act
specifically. Indicia of congressional intent can vary from one
statute to another and we must take care to conduct an
individualized inquiry. Indeed, in Simplex itself we
“express[ed] no opinion as to the interpretation of any other
statutes that include similar provisions.” 766 F.2d at 583 n.2.

     The Secretary’s criticism that Simplex contained no
independent analysis of the OSH Act’s legislative history is not
especially persuasive. Although the relevant discussion in
Simplex is limited to a footnote, it does not follow that this court
therefore adopted by rote the position taken by the majority of
our sister circuits. On the contrary, Simplex made clear that we
had “considered the evidence of congressional intent put
forward in these cases,” and were “doing no more than
interpreting congressional intent as to the preclusive effects of
[the OSH Act]’s provision for pre-enforcement review.” Id.
Nor can it be said that Simplex was decided without regard to
“any of the relevant policy concerns this court would later
recognize.” Sec’y’s Suppl. Br. 10. JEM was not the first time
we addressed the finality interest at stake in belated procedural
challenges. “In a long line of cases” going back to Functional
                               17
Music, Inc. v. FCC, 274 F.2d 543 (D.C. Cir. 1958), cert.
denied, 361 U.S. 813 (1959), “this court has repeatedly
distinguished indirect attacks on the substantive validity of
regulations initiated more than sixty days after their
promulgation from like attacks on their procedural lineage.”
NLRB Union v. FLRA, 834 F.2d 191, 195 (D.C. Cir 1987). Yet
Simplex did not cite Functional Music or any related case; it
relied entirely on persuasive authority addressing the unique
considerations underlying the OSH Act’s review scheme. See
766 F.2d at 582 n.2. In other words, the Simplex court found
the Congress’s intent behind the OSH Act—not generalized
finality concerns—critical to the question of section 6(f)’s
preclusive effect.

     Equally unavailing is the Secretary’s reliance on RSR
Corp. v. Donovan, 747 F.2d 294 (5th Cir. 1984). In RSR Corp.,
the Fifth Circuit declined to extend Deering Milliken—one of
the cases Simplex chiefly relied upon—and did not entertain a
substantive validity challenge in an enforcement proceeding.
Id. at 302. The Secretary curiously claims that Simplex lacked
“the benefit of . . . [this] subsequent decision,” Sec’y’s Suppl.
Br. 15, but Simplex was decided over six months after RSR
Corp., compare Simplex, 766 F.2d at 575 (July 5, 1985), with
RSR Corp., 747 F.2d at 294 (November 26, 1984). Moreover,
RSR Corp. is readily distinguishable. Whereas the standards at
issue in Deering Milliken, Simplex and this case were adopted
under section 6(a), the challenged regulation in RSR Corp. was
promulgated under section 6(b), a distinction the Fifth Circuit
took care to emphasize. See RSR Corp., 747 F.2d at 300–01.
Employers may have been “lulled” by the fact that section 6(a)
standards were supposed to “be pre-existing and familiar to
industry” and it would have been “quite burdensome to comb
through every 6(a) regulation and object to inappropriate
promulgations within sixty days, considering the ‘multitude of
regulations (which) could have been promulgated without
                               18
notice or hearing within two years of the enactment of’” the
OSH Act. Deering Milliken, 630 F.2d at 1099 (quoting Union
Oil, 616 F.2d at 1118). RSR, on the other hand, “was neither
‘lulled’ nor inactive with respect to” the challenged regulation.
RSR Corp., 747 F.2d at 301. It participated not only in the
notice-and-comment process mandated by section 6(b), but
also in pre-enforcement judicial review under section 6(f). Id.
at 298. Plainly, different finality interests are implicated if an
employer has in fact had ample opportunity to express validity
concerns and tries for a second bite at the apple.

     We see no reason to disregard Simplex’s determination
that the OSH Act allows for a procedural challenge in an
enforcement proceeding, at least for section 6(a) standards. See
also Deering Milliken, 630 F.2d at 1099 (“[T]he potential
number and technical complexity of summarily promulgated
regulations[] makes it particularly inappropriate to find section
6(f) a bar to procedural attack[s] on 6(a) regulations.”).
Accordingly, we do not reach Kiewit’s alternative arguments,
including whether section 6(f) is, in fact, non-jurisdictional.

                               III.

     As a preliminary matter, we consider Kiewit’s motion for
leave to add rebuttal arguments, which it deems necessary in
order to respond to several points raised in the reply portion of
the Secretary’s reply and cross-respondent’s brief. We
disagree. Although styled differently, Kiewit’s motion for
leave to add rebuttal arguments seeks, in effect, to file a
surreply. See, e.g., Gibbons v. McBride, 124 F. Supp. 3d 1342,
1383 (S.D. Ga. 2015) (“The purpose of a [surreply] is to rebut
arguments advanced in an opposing party’s reply brief . . . .”)
(citation omitted). “Surreplies are generally disfavored and
[Kiewit] has not demonstrated that the requested relief is
                                19
warranted.” Hall v. U.S. Dep’t of Labor, No. 18-5100, 2018
WL 5919255, at *1 (D.C. Cir. Nov. 1, 2018).

     First, Kiewit asserts that the Secretary’s reply brief
improperly made several new arguments. It is true that “[w]e
will not consider a novel contention first advanced in a reply
brief,” Asociacion de Compositores y Editores de Musica
Latinoamericana v. Copyright Royalty Tribunal, 809 F.2d 926,
928 (D.C. Cir. 1987), but that is not the case here. The
arguments Kiewit complains of appear in the Secretary’s
principal brief, in substantially similar form. The real issue,
then, is that Kiewit disagrees with the Secretary’s position. For
example, Kiewit claims the Secretary’s reply brief added new
points on legislative history but the substance of its proposed
rebuttal focuses solely on the Secretary’s purported textual
mischaracterizations.8 That the Secretary draws different
conclusions from the underlying sources is insufficient to
justify a rebuttal. And to the extent the Secretary adopted any
“new” positions, he was simply responding to contentions
made by Kiewit. This is the very nature of a reply brief. See,
e.g., United States v. Van Smith, 530 F.3d 967, 973 (D.C. Cir.
2008). Nor has Kiewit demonstrated that rebuttal argument is
warranted to respond to several alleged misstatements in the
Secretary’s reply brief. Kiewit does not claim the offending
arguments were newly raised. Instead, it simply frames the
interpretive dispute as the basis for additional briefing.

   Finally, Kiewit contends the Secretary’s argument that we
may not distinguish cases on grounds not used by the

    8
         In fact, Kiewit has itself mischaracterized the alleged
mischaracterizations. For example, it quotes language from the
Secretary’s brief, making much of the fact that the exact wording
does not appear in any of the Secretary’s cited sources. But Kiewit
references the Secretary’s own language—it is entirely expected that
the Secretary’s word choice differs from the sources he cites.
                               20
Commission is inconsistent with circuit precedent. This dispute
is ultimately irrelevant to our disposition because we do not
decide the Secretary’s arbitrary-and-capricious challenge. See
infra at 37. In any event, rebuttal briefing is unwarranted. The
Secretary’s argument was in response to Kiewit—not the
Commission—so it could not have been raised earlier than the
reply brief. Although Kiewit concedes it could raise the same
objections in a letter filed pursuant to Federal Rule of Appellate
Procedure 28(j), it touts the fact that permitting a rebuttal
argument will save ninety-two words. There are good reasons
why this minute reduction, without more, does not justify a
departure from the normal cross-briefing rules. In contrast to
the proposed rebuttal, the Secretary would have an opportunity
to respond to a 28(j) letter. Allowing rebuttal argument on these
facts risks opening the door to any litigant that disagrees with
the opposing party’s arguments to evade the standard briefing
requirements and gain the last word. We decline to do so and
deny Kiewit’s motion in full.

                               IV.

       We review the Commission’s orders according to
“[f]amiliar principles of administrative law” and set aside its
“legal determinations . . . [if] they are ‘arbitrary, capricious,
. . . or otherwise not in accordance with law.’” A.J. McNulty &
Co. v. Sec’y of Labor, 283 F.3d 328, 331–32 (D.C. Cir. 2002)
(quoting 5 U.S.C. § 706(2)(A)). At issue is whether OSH Act
section 6(a) authorized the Secretary to apply the quick-
drenching provision to industries beyond those covered by the
original Walsh-Healey standard. We generally defer to the
Secretary’s interpretation “so long as the statutes and
regulations in question are ambiguous and the Secretary’s
interpretations are reasonable,” AKM LLC v. Sec’y of Labor,
675 F.3d 752, 754 (D.C. Cir. 2012) (citing Chevron, U.S.A.,
Inc. v. Nat. Res. Def. Council, 467 U.S. 837, 843 (1984)), but
                               21
our inquiry is “a little unusual” because the Secretary and the
Commission have adopted conflicting interpretations of the
OSH Act and its implementing regulations, S.G. Loewendick &
Sons, Inc. v. Reich, 70 F.3d 1291, 1294 (D.C. Cir. 1995).

      “When, as here, ‘the Secretary and the Commission divide,
it [is] . . . the Secretary rather than the Commission [who] is
entitled to” deference, Sec’y of Labor v. Excel Mining, LLC,
334 F.3d 1, 6 (D.C. Cir. 2003) (alterations in original) (quoting
Sec’y of Labor v. Cannelton Indus., Inc., 867 F.2d 1432, 1435
(D.C. Cir. 1989)), “even where the Secretary offers his
interpretation in the context of litigation before the
Commission,” S.G. Loewendick & Sons, 70 F.3d at 1294 (citing
Martin, 499 U.S. at 157 (“[T]he Secretary’s litigating position
before the Commission is as much an exercise of delegated
lawmaking powers as is the Secretary’s promulgation of a
workplace health and safety standard.”)). This approach
reflects “the distinct functions of the Commission and of the
Secretary. Because the Secretary, not the Commission, is the
policymaker, we defer to the Secretary’s interpretation . . . .
We do not owe the same deference to interpretations
independently offered by the Commission . . . .” Id. at 1294
(citing Martin, 499 U.S. at 156–57). And because we “treat the
Commission ‘as equivalent to a “nonpolicymaking” district
court,’” id. at 1295 (quoting Molineaux v. United States, 12
F.3d 264, 267 (D.C. Cir. 1994)), it too must defer to the
Secretary’s reasonable interpretations, see Excel Mining, 334
F.3d at 5–6.

    “Under step one of Chevron, we ‘ask whether Congress
has directly spoken to the precise question at issue, in which
case we must give effect to the unambiguously expressed intent
of Congress.’” Sec’y of Labor v. Nat’l Cement Co. of Cal., 494
F.3d 1066, 1073–74 (D.C. Cir. 2007) (quoting Bluewater
Network v. EPA, 372 F.3d 404, 410 (D.C. Cir. 2004) (internal
                                  22
quotation marks omitted)). “If the ‘statute is silent or
ambiguous with respect to the specific issue,’ however, we
move to the second step and defer to the agency’s interpretation
as long as it is ‘based on a permissible construction of the
statute.’” Bluewater Network, 372 F.3d at 410 (quoting
Chevron, 467 U.S. at 843). We agree with the Commission that
the OSH Act is ambiguous regarding the Secretary’s authority
to apply established Federal standards to new industries under
section 6(a), see OSHRC Decision at 1448,9 but we conclude
that the Secretary’s interpretation of his section 6(a) authority
is permissible and therefore owed deference by the
Commission.

                                  A.

     “To discern the Congress’s intent, we generally examine
the statutory text, structure, purpose and its legislative history.”
Lindeen v. SEC, 825 F.3d 646, 653 (D.C. Cir. 2016) (citing Bell
Atl. Tel. Cos. v. FCC, 131 F.3d 1044, 1047 (D.C. Cir. 1997)).
“The starting point for our interpretation of a statute is always
its language.” Cmty. for Creative Non-Violence v. Reid, 490
U.S. 730, 739 (1989) (citing Consumer Prod. Safety Comm’n
v. GTE Sylvania, Inc., 447 U.S. 102, 108 (1980)). Section 6(a)
instructs the Secretary to “promulgate as an occupational safety
or health standard . . . any established Federal standard,” 29
U.S.C. § 655(a), but does not address whether the scope of the
new OSH standard must mirror its source standard. The silence
does not end our step-one analysis. Rather, to assess “[t]he
plainness or ambiguity of statutory language,” we must also

     9
        Kiewit asserts that “[t]he Commission correctly held that the
legislative history shows congressional intent so clearly as to satisfy
Chevron Step One.” Kiewit Br. 41. Kiewit does not support its
contention with any citation to the Commission decision. Nor could
it, as Kiewit’s claim flatly contradicts the Commission’s express
“find[ing] that section 6(a) is ambiguous.” OSHRC Decision at 1448.
                                  23
consider “the broader context of the statute as a whole.”
Robinson v. Shell Oil Co., 519 U.S. 337, 341 (1997).

     We recognized in Simplex that the Secretary, when acting
pursuant to section 6(a), may not make a “substantially [sic]
meaningful modification of the [established Federal]
standard . . . during [its] transformation into an” OSH standard.
766 F.2d at 584 (quoting Deering Milliken, 630 F.2d at 1100).10
Although the Secretary contends that a modification is
substantive only if it alters a standard’s protective terms, not its
scope, Kiewit maintains that extending Walsh-Healey
standards to the construction industry was in fact a substantive
modification in contravention of the OSH Act’s plain meaning
because the revocation of § 1910.5(e) “changed § 1910.151(c)
from inapplicable and not imposing a duty on constructors, to
applicable and imposing one.” Kiewit Br. 52. Kiewit notes that
when the Secretary promulgated the initial CSA standards, the
language of the “Medical Services and First Aid” standard was
largely borrowed from 41 C.F.R. § 50-204.6, the Walsh-

     10
          Although Simplex asked whether the modification was
“substantially meaningful,” 766 F.2d at 584 (emphasis added), it
purported to quote Deering Milliken, which framed the inquiry as
“whether a substantively meaningful modification of the Walsh-
Healey standard occurred,” 630 F.2d at 1100 (emphasis added). This
subtle difference may be attributable to the fact that Simplex involved
a national consensus standard. In that context, the Secretary is
required to publish an explanation whenever a promulgated rule
“differs substantially from an existing national consensus standard.”
29 U.S.C. § 655(b)(8). In any event, the choice of language does not
alter our analysis of the established Federal standard at issue here.
See, e.g., Diebold, Inc. v. Marshall, 585 F.2d 1327, 1332 (6th Cir.
1978) (section 6(a) “required adoption of ‘established Federal’ and
‘national consensus’ standards without substantive modification”).
Indeed, Kiewit, after invoking Simplex’s “substantially meaningful”
articulation, argues that the quick-drenching standard was
substantively modified. See Kiewit Br. 36–38.
                               24
Healey standard that contains the quick-drenching provision.
See Safety and Health Regulations for Construction, 36 Fed.
Reg. 7340, 7347–48 (Apr. 17, 1971). Yet the quick-drenching
provision was not carried over. Id. Any conclusion drawn from
this omission is necessarily speculative. Kiewit has provided
no evidence that the quick-drenching provision was debated at
this time—just that the rest of § 50-204.6 informed the new
CSA standard. Rather, it contends that the applicability of the
Walsh-Healey standards to the construction industry, including
the quick-drenching provision, remained a topic of debate until
the 1993 codification of certain general standards as
construction standards. But this contention is not inconsistent
with the Secretary’s position that general standards apply if no
particular standard addresses the same hazard or working
condition. See 29 C.F.R. § 1910.5(c)(1)–(2); Incorporation of
General Industry Safety and Health Standards Applicable to
Construction Work, 58 Fed. Reg. at 35,076 (“[S]ince early in
its existence, . . . [OSHA] has determined that it is appropriate
to cite a construction employer for violation of a part 1910
standard, to effectuate the purposes of the OSH Act.”). Simply
because the extent of the coverage overlap between Walsh-
Healey and CSA standards was not immediately apparent does
not mean that the former’s extension to new industries
necessarily constituted a substantive modification.

     That said, the line between substantive and non-
substantive modification is not easy to discern. According to
Kiewit, “[s]ubstantive modification means that one is not
adopting the ‘established Federal standard.’” Kiewit Br. 35
(citing Usery v. Kennecott Copper Corp., 577 F.2d 1113,
1117–18 (10th Cir. 1977)). But Kiewit’s definition is far from
elucidating and leaves open what it means to “not adopt” a
source standard. It cannot be that any minor deviation
automatically exceeds the Secretary’s authority for he was not
“required to promulgate existing . . . federal standards
                              25
verbatim.” Simplex, 766 F.2d at 584 (quoting Deering Milliken,
630 F.2d at 1100). The question, then, is how much a source
standard can be altered before the modification is
impermissibly substantive. As the Commission previously
recognized, the answer depends on congressional intent.
“[C]hanges in a source standard are permissible if they are the
sort of changes that Congress allowed the Secretary to make,”
Am. Can Co., 10 BNA OSHC at 1311, but, here, the OSH Act
is ambiguous on the point.

    Neither Kiewit nor the Commission disputes that some
modification of established Federal standards is acceptable,
contemplating that the Secretary could extend the scope of such
standards to cover new employers in the original industry. See
OSHRC Decision at 1453 (section 6(a) allowed Secretary to
expand scope of Walsh-Healey standards “to all manufacturers,
not just those with federal contracts”); Kiewit Br. 38
(“[S]ubstantive change would not occur when the Walsh-
Healey and Construction Safety standards . . . were extended to
all manufacturers and constructors.”). Kiewit and the
Commission draw the line, however, at the extension to
employers in a different industry. But the language of the OSH
Act does not plainly support this implicit limitation.

     Granted, there are some colorable arguments that the scope
of a new OSH standard promulgated under section 6(a) was
intended to mirror that of its source standard. Established
Federal standards encompass “any operative [OSH] standard
established by any agency of the United States and presently in
effect.” 29 U.S.C. § 652(10). In turn, an OSH standard
“requires conditions, or the adoption or use of one or more
practices, means, methods, operations, or processes,
reasonably necessary or appropriate to provide safe or healthful
employment and places of employment.” Id. § 652(8). Kiewit
contends that once a standard found to be “reasonably
                                  26
necessary or appropriate” for the protection of workers in a
specific industry is extended to additional industries, it is no
longer the same established Federal standard because no
finding has been made that the standard is in fact “reasonably
necessary or appropriate” for the new “employment” and
“places of employment.” See Kiewit Br. 36–37. Accordingly,
Kiewit asserts that the Secretary cannot utilize section 6(a)—
which authorizes the promulgation of established Federal
standards “presently in effect”—to extend the quick-drenching
standard to the construction industry because he never found
the standard “reasonably necessary or appropriate” to protect
construction workers.11 Id.

    At the same time, the express limitations on the
Secretary’s section 6(a) authority suggest a more expansive
scope for newly adopted OSH standards. The OSH Act

     11
          The Commission made a related argument, asserting that
Walsh-Healey standards “‘presently in effect’ at the time did not
apply to the construction industry,” OSHRC Decision at 1450, but
its position is unpersuasive. As Commissioner Attwood noted in her
dissent, “presently in effect” is more naturally read as a requirement
that the established Federal standard must have been “on the books,”
i.e., “in effect on or after the effective date of the OSH Act.” Id. at
1457–58 (Attwood, Comm’r, dissenting). Moreover, rigidly fixing
the scope of established Federal standards would preclude even the
more limited extensions that the Commission itself accepted. That is,
extending a Walsh-Healey standard to manufacturers without federal
contracts also alters the scope of the standard “presently in effect” at
the time of promulgation. The Commission replies that established
Federal standards must also be “operative” and that Walsh-Healey
standards “were operative only as to the manufacturing industry.” Id.
at 1450 fn. 11 (majority opinion). Yet the Commission does not
dispute that all manufacturers would be covered by a new OSH
standard, even though manufacturers without federal contracts fell
outside the “operative” scope of the precursor Walsh-Healey
standard. See id.
                                 27
instructs the Secretary to promulgate any established Federal
standard “unless he determines that the promulgation of such a
standard would not result in improved safety or health for
specifically designated employees.” 29 U.S.C. § 655(a). If
adopting a Walsh-Healey standard as an OSH standard
expanded coverage to manufacturers and suppliers without
federal contracts only, it is difficult to imagine when such a
standard would not result in improved safety or health for the
newly covered employees inasmuch as, before the OSH Act,
they would not have been protected by any mandatory safety
or health standards. Kiewit responds that the Secretary was not
authorized to modify a standard, only to refrain from adopting
it.12 But this assertion does not explain when it would be
appropriate to not adopt an established Federal standard, if the
standard continued to apply only in the industry for which it
was originally promulgated. The anticipation that a standard
would not improve safety, or that there may be “conflict among
any such standards,” id., seems to require that an OSH
standard’s scope exceed that of its source standard. At a
minimum, it is at least plausible “that established federal
standards must be expanded to cover employees in additional
industries unless application of the standards to the
‘specifically designated employees’ in that industry ‘would not
result in improved safety or health.’” OSHRC Decision at
1456–57 (Attwood, Comm’r, dissenting). Put differently, the
new OSH standards could be extended to cover employees in a
new industry if those employees were not already protected by
an analogous, industry-specific standard. This seems a
reasonable construction of the OSH Act but it does not
     12
        Kiewit argued that section 6(a)’s exemption for standards not
improving health or safety was intended to address national
consensus standards. See Oral Argument at 26:50–27:06, 27:43–47
(Oct. 10, 2019). The text of the provision, however, draws no such
distinction and plainly applies with like force to established Federal
standards.
                                  28
foreclose Kiewit’s reading that the scope of an OSH standard
promulgated under section 6(a) is tied by implication to the
same industry as its source standard, even if the standard now
extends to additional employers within that industry.13 The
plain language of the OSH Act does not reveal the extent to
which the Secretary could expand the scope of section 6(a)
standards without resorting to formal rulemaking under section
6(b). “[T]he fact that the provision can support two plausible
interpretations renders it ambiguous for purposes of Chevron
analysis.” AFL-CIO v. FEC, 333 F.3d 168, 174 (D.C. Cir.
2003) (citing United States v. Nofziger, 878 F.2d 442, 446–47
(D.C. Cir. 1989)).

                                  B.

    “At Chevron step two, ‘the question for the court is
whether the agency’s interpretation is based on a permissible
construction of the statute in light of its language, structure, and
purpose.’” Nat’l Treasury Emps. Union v. FLRA, 754 F.3d
1031, 1042 (D.C. Cir. 2014) (quoting AFL-CIO v. Chao, 409

     13
        We agree with the Commission that the Secretary’s reliance
on OSH Act section 4(b)(2)—which provides that standards issued
under preexisting labor laws are deemed OSH standards issued under
both the OSH Act and the preexisting labor laws, until superseded
by corresponding standards the Secretary deems more effective—is
misplaced. See 29 U.S.C. § 653(b)(2); OSHRC Decision at 1451–
1452, 1452 n.14. The legislative history indicates that section 4(b)(2)
was intended “to insure that standards under existing laws will not
be repealed” by the OSH Act’s enactment and instead “remain
effective until superseded by the promulgation of standards under
section 6a” in order to “preserv[e] remedies available under existing
laws.” 116 Cong. Rec. 42,206 (1970) (statement of Rep. Steiger).
Accordingly, section 4(b)(2) “has no bearing on whether section 6(a)
authorized the Secretary to expand the scope of established federal
standards to additional industries.” OSHRC Decision at 1452. But
see Sec’y’s Br. 30 & n.7.
                              29
F.3d 377, 384 (D.C. Cir. 2005) (internal quotation marks and
citations omitted)). And, as outlined supra, “[b]ecause the
Commission’s powers are solely adjudicatory,” it too “must
defer to the Secretary’s reasonable interpretations.” S.G.
Loewendick & Sons, 70 F.3d at 1294. But, here, the
Commission withheld deference based on its conclusion that
the revocation of § 1910.5(e) was an arbitrary and capricious
policy change and that the Secretary’s interpretation of section
6(a) was unreasonable. OSHRC Decision at 1449–50. We
address each argument in turn.

                              1.

     The Commission found the revocation of § 1910.5(e) to be
procedurally defective and, accordingly, the Secretary’s
interpretation embodied therein—that section 6(a) authorized
the extension of established Federal standards to new
industries—undeserving of Chevron deference. See id. at 1449
(“‘[D]eference is not warranted,’ however, ‘where the
regulation is “procedurally defective”—that is, where the
agency errs by failing to follow the correct procedures in
issuing the regulation.’” (quoting Encino Motorcars, 136 S. Ct.
at 2125)). The Commission’s reliance on Encino Motorcars is
misplaced. There, DOL issued a 1978 opinion letter departing
from the position it had adopted eight years earlier in an
interpretive regulation. 136 S. Ct. at 2123. Over the ensuing
decades, DOL continued to affirm its 1978 interpretation and,
in 2008, finally published a notice of proposed rulemaking to
revise the 1970 regulation to accord with existing practice. Id.
In 2011, however, “the Department changed course yet again”
and “issu[ed] a final rule that took the opposite position from
the proposed rule,” abandoning the policy it had applied over
the past thirty-plus years in favor of its original 1970
interpretation. Id. Critically, “[t]he Department gave little
explanation for its decision to abandon its decades-old
                              30
practice,” id., and the “lack of reasoned explication for a
regulation that is inconsistent with the Department’s
longstanding earlier position” meant that the “regulation does
not receive Chevron deference,” id. at 2127. The lack of
deference reflected more than DOL’s faulty reasoning—
indeed, the Supreme Court acknowledged DOL’s “summary
discussion may suffice in other circumstances.” Id. at 2126.
Rather, key to understanding Encino Motorcars is the Court’s
recognition that, under the circumstances, a cursory
explanation was inadequate “in particular because of decades
of industry reliance on the Department’s prior policy.” Id. In
other words, the unexplained departure was especially
egregious because DOL’s reversal repudiated the position it
had repeatedly affirmed to employers for over thirty years.

     Encino Motorcars is readily distinguishable. First, the
revocation of § 1910.5(e) in September 1971 did not implicate
the same reliance concern. Unlike the “decades-old practice” at
issue in Encino Motorcars, id. at 2123, § 1910.5(e) “existed for
less than four months, was in effect for less than two weeks,
and was never even published in the Code of Federal
Regulations,” OSHRC Decision at 1462 (Attwood, Comm’r,
dissenting). Moreover, employers were on notice that changes
to the newly promulgated regulations could occur without
further rulemaking because the Secretary expressly retained his
section 6(a) authority for two years and could “modify or
revoke” any Part 1910 standard without notice and comment.
29 C.F.R. § 1910.4(b). And in the event of conflict between
Part 1910 standards, necessary action—including modification
or revocation—should be taken to eliminate the conflict “so as
to assure the greatest protection of the safety or health of the
affected employees.” Id.
                                 31
    The plain tension between § 1910.5(c)(2) and
§ 1910.5(e)14 manifests that § 1910.5(e)’s revocation was not a


     14
         The Secretary also identifies a conflict between § 1910.5(e)
and § 1910.11 but his argument is less convincing on this point.
Section 1910.11 provides that “[t]he provisions of this Subpart B
adopt and extend the applicability of, established Federal standards
in effect on April 28, 1971, with respect to every employer,
employee, and employment covered by the Act.” 29 C.F.R.
§ 1910.11(a). Because § 1910.11 is itself codified in Subpart B, the
Secretary contends it is made operative, by its own terms, to all
established Federal standards, including Walsh-Healey standards,
thereby extending such standards to every employer covered by the
OSH Act. Better read, § 1910.11 indicates that the industry specific
standards in Subpart B were not to retain the same coverage
limitations as their source standards but were to apply to additional
employers within the relevant industry. Cf. Bechtel Power Corp., 4
BNA OSHC 1005, 1008 (No. 5064, 1976) (Secretary was authorized
to extend, without resorting to formal rulemaking, coverage of CSA
standards to construction-industry employers not subject to the CSA
standards). The Walsh-Healey standards—which were not
incorporated into Subpart B—would therefore be unaffected by
§ 1910.11 and would instead be subject to the general provisions set
forth in Subpart A. That said, we are unpersuaded by Kiewit’s
contention that this purported conflict could not have caused §
1910.5(e)’s revocation because the Secretary did not also identify a
conflict between § 1910.11 and the circumscribed scope provisions
in Subpart B. See, e.g., 29 C.F.R. § 1910.12 (CSA standards
incorporated by reference from Part 1926 apply only to “construction
work”). Despite maintaining work-based limitations, these scope
provisions still extended coverage to employments not covered by
the CSA standards. See, e.g., Bechtel Power Corp., 4 BNA OSHC at
1007 (construction manager subject to OSH standards even though
CSA standards applied only to contractors and subcontractors). In
contrast, § 1910.5(e) alone retained the restrictions of a preexisting
statute, limiting Walsh-Healey derived standards to employment that
would be subject to the Walsh-Healey Act if a federal contract were
                                 32
“complete about-face,” OSHRC Decision at 1449, but, instead,
was carried out to “remove[] the anomaly created by the
conflicting . . . provisions,” id. at 1462 (Attwood, Comm’r,
dissenting); see also Diebold, Inc. v. Marshall, 585 F.2d 1327,
1335 (6th Cir. 1978) (“Given the wide variety of sources for
the initial standards package and the rapidity of its
promulgation, we would be frankly surprised if there were not
anomalies.”) (emphasis added). Section 1910.5(c)(1) explains
the interplay between a “particular standard . . . applicable to a
condition, practice, means, method, operation, or process” and
a general industry standard, providing that the particular
standard “shall prevail over any different general standard
which might otherwise be applicable.” 29 C.F.R.
§ 1910.5(c)(1). “On the other hand, any standard shall apply
according to its terms to any employment and place of
employment in any industry, even though particular standards
are also prescribed for the industry, as in [S]ubpart B or
[S]ubpart R of this part, to the extent that none of such
particular standards applies.” Id. § 1910.5(c)(2) (emphasis
added). Subpart B encompasses the “particular standards”
adopted for the construction industry. See id. § 1910.12. The
import of this basic structure aligns with the Secretary’s
framing of his initial interpretation: the OSH Act authorized
him to apply general standards (i.e., those derived from Walsh-
Healey standards) to “any industry” unless that industry
already had a particular standard addressing the same condition
or hazard. See Anthony Crane Rental, Inc. v. Reich, 70 F.3d
1298, 1302 (D.C. Cir. 1995) (“Under this regulatory scheme,
the general industry standards apply unless they are preempted
by specific industry standards.”). The limitation outlined in
§ 1910.5(e) plainly conflicts with § 1910.5(c) as a regime
wherein general industry standards plug regulatory gaps would


involved. It does not seem inconsistent for the Secretary to identify
a conflict in the latter situation but not the former.
                               33
be toothless if only CSA standards could apply to the
construction industry.

     It makes sense that the Secretary retained § 1910.5(c) at
§ 1910.5(e)’s expense given the OSH Act’s express instruction
that the Secretary favor more expansive protection. See 29
U.S.C. § 655(a) (“In the event of conflict among any such
standards, the Secretary shall promulgate the standard which
assures the greatest protection of the safety or health of the
affected employees.”). And the published notice, despite its
brevity, reflects this purpose. See Applicability of Some
Established Federal Standards, 36 Fed. Reg. at 18,081
(revocation intended “to remove the limitation to the
application of the standards so that they may apply to every
employment and place of employment exposed to the hazards
covered by the standards.”). These facts thus contrast sharply
with those in Encino Motorcars, where employers were told a
decades-long policy would be reflected in the revised
regulation, only to have DOL inexplicably veer in the opposite
direction. Ironically, despite the Commission’s invocation of
reliance interests, its decision, not the Secretary’s, invalidates
an interpretation that has stood for nearly fifty years.

     Moreover, it is a troubling proposition to withhold
deference based on the absence of formal rulemaking when, if
the Secretary correctly construed the boundaries of his section
6(a) authority, it was proper for him to act without notice-and-
comment procedures. The well-established principle of
administrative law underpinning Encino Motorcars and the
Commission’s decision is that “where the agency has failed to
provide even [a] minimal level of analysis, its action is
arbitrary and capricious and so cannot carry the force of law.”
Encino Motorcars, 136 S. Ct. at 2125 (citing 5 U.S.C.
§ 706(2)(A)). Granted, “[e]xemptions from the terms of the
Administrative Procedure Act are not lightly to be presumed,”
                                  34
Marcello v. Bonds, 349 U.S. 302, 310 (1955), so we must ask
“whether Congress has established procedures so clearly
different from those required by the APA that it must have
intended to displace the norm,” Asiana Airlines v. FAA, 134
F.3d 393, 397 (D.C. Cir. 1998).

     The OSH Act expressly exempted the Secretary from APA
rulemaking, instructing him to promulgate OSH standards
under section 6(a) “[w]ithout regard to chapter 5 of Title 5.” 29
U.S.C. § 655(a); see OSHRC Decision at 1459 n.10 (Attwood,
Comm’r, dissenting) (“Section 6(a) . . . is an unambiguous,
comprehensive statement mandating that all rulemaking
authorized thereunder is exempt from all APA
requirements . . . .”). It is undisputed that, for two years, the
Secretary could issue OSH standards using section 6(a)’s
informal procedure. Indeed, Kiewit does not contest the
validity of other section 6(a) standards, all of which were
promulgated without notice and comment or reasoned
explanation. The question, then, is whether the challenged
standards were required to carry over their source standards’
industry-centric scopes. In answering, the Commission’s view
on the merits of the Secretary’s position fused with its
determination that his interpretation was procedurally
defective, presuming the Secretary could not expand the scope
of standards promulgated under section 6(a). This was
improper because if, as the Secretary maintains, the standards
could be applied to new industries—an interpretive question
usually given deference—the Secretary cannot be faulted for
bypassing procedures from which the Congress expressly
exempted him.15 For the same reasons, we reject Kiewit’s

     15
         We are skeptical of Kiewit’s contention that section 6(a)’s
express procedural exemption does not foreclose the Commission’s
reliance on Encino Motorcars because “the Commission never
attributed its holding to the APA” and “[a]rbitrary and capricious
action is also prohibited by the Due Process Clause . . . .” Kiewit Br.
                               35
contentions that deference is unwarranted because “OSHA is
interpreting the OSH Act so as to limit the APA,” Kiewit Br.
34, and that the APA’s anti-supersession clause, 5 U.S.C.
§ 559, requires a narrow construction of section 6(a). Like the
Commission, Kiewit looks past the OSH Act’s express
exemption from APA rulemaking and ignores the fact that if,
as we conclude, section 6(a) authorized the Secretary to extend
former Walsh-Healey standards beyond the manufacturing and
supply industries, the usual rulemaking procedures were in fact
displaced.

     Kiewit’s additional arguments against Chevron’s
application are unpersuasive. First, the “[c]ases applying
Chevron-displacing rules,” Kiewit Br. 31 n.9, are inapposite
because, unlike this case, they implicate unique issues
justifying departure from normal interpretive principles,
including retroactivity, see INS v. St. Cyr, 533 U.S. 289, 320
n.45 (2001) (“Because a statute that is ambiguous with respect
to retroactive application is construed under our precedent to
be unambiguously prospective, there is, for Chevron purposes,
no ambiguity in such a statute for an agency to resolve.”
(citation omitted)), and Indian law, see Muscogee (Creek)
Nation v. Hodel, 851 F.2d 1439, 1444 (D.C. Cir. 1988) (“[T]he
standard principles of statutory construction do not have their
usual force in cases involving Indian law.”). Nor is Chevron
displaced merely because the Commission and the Secretary
disagree. Contrary to Kiewit’s suggestion, we are not
concerned that “the Executive speaks from both sides of its
mouth, articulating no single position on which it might be held

30–31 (citation omitted). Even were we to ignore the explicit APA
references elsewhere in the decision, see, e.g., OSHRC Decision at
1451 (“Modification to APA Notice-and-Comment Process Not to
Be Lightly Presumed.”), it remains a stretch to conclude that the
Commission tacitly employed a due process analysis in relying on
Encino Motorcars, a decision that never mentions “due process.”
                              36
accountable,” Epic Sys. Corp. v. Lewis, 138 S. Ct. 1612, 1630
(2018), because only the Secretary’s interpretation receives
deference here. Finally, Kiewit argues that Chevron does not
apply because § 1910.5(e)’s revocation “followed no formal
process.” Kiewit Br. 33 (citing United States v. Mead Corp.,
533 U.S. 218 (2001)). Kiewit again gives short shrift to section
6(a)’s express exemption from formal rulemaking; the logical
extension of Kiewit’s argument is that no interpretation
embodied in a regulation promulgated under section 6(a)
warrants Chevron deference. But Section 6(a) authorized the
Secretary “to make rules carrying the force of law,” Mead, 533
U.S. at 226–27, and the “interpretation claiming deference was
promulgated in the exercise of that authority,” id. at 227.

     In sum, the Commission erred in withholding Chevron
deference on account of purported procedural defects. We now
address its determination that the Secretary’s interpretation of
section 6(a) is unreasonable.

                               2.

     “[W]e must accept the [Secretary]’s interpretation if it is
merely permissible.” Wagner Seed Co. v. Bush, 946 F.2d 918,
925 (D.C. Cir. 1991). “We need not conclude that the
[Secretary]’s interpretation of the [OSH Act] is ‘the only one
[he] permissibly could have adopted,’ or ‘even the
interpretation deemed most reasonable by the courts.’” Nat’l
Treasury Emps. Union v. FLRA, 754 F.3d 1031, 1042 (D.C.
Cir. 2014) (citations omitted) (first quoting Chevron, 467 U.S.
at 843 n.11; then quoting Entergy Corp. v. Riverkeeper, Inc.,
556 U.S. 208, 218 (2009)). Here, the Secretary’s interpretation
of his authority under section 6(a) is not “[in]consistent with
the terms of the statute and not unreasonable” and “therefore,
entitled to our deference.” Chippewa & Flambeau
Improvement Co. v. FERC, 325 F.3d 353, 360 (D.C. Cir. 2003).
                                37
     First, we disagree that the Secretary’s interpretation
creates absurdities by condoning, for example, the application
of “maritime or shipbuilding standards . . . to the manufacturing
industry, or construction standards . . . to the agricultural
industry.” OSHRC Decision at 1451. This argument “reflects a
fundamental misunderstanding of OSHA’s regulatory
scheme,”       which         contemplates      “that     standards
apply . . . wherever the working conditions and hazards
addressed by the standard exist.” Sec’y’s Br. 32 n.8. A standard
applied to a specialized line of work is, by its terms, unlikely
to apply in a different setting where the same risk does not
exist. For example, a standard addressing a danger found only
in the agricultural industry will not apply to work in a
manufacturing plant. But when the same hazardous
condition—e.g., exposure to corrosive materials—exists in
different industries, it is reasonable to apply a relevant standard
across industry lines. And the likelihood of absurd results is
further mitigated by the approach outlined in § 1910.5(c),
which contemplates that general industry standards apply only
if a specific industry standard does not already address the
condition at issue.

     True, cross-industry application may not be appropriate in
all cases. The unique characteristics of an industry may make
it infeasible for an employer to adopt a general standard,
thereby requiring a different solution to abate the same hazard.
Indeed, Kiewit asserts that applying the quick-drenching
standard to construction poses feasibility problems—
construction sites typically lack plumbing and frequent crew
movement requires the relocation of portable water containers.
But, in addition to the variance procedure set out in OSH Act
section 6(d), 29 U.S.C. § 655(d),16 if “strict compliance with a

    16
       “Any affected employer may apply to the Secretary for a rule
or order for a variance from a standard promulgated under [section
                                  38
standard is physically impossible or would prevent
performance of the work, employers may instead take
alternative protective measures,” Am. Can Co., 10 BNA OSHC
at 1310. And whether an employer has provided “suitable
facilities for quick drenching,” 29 C.F.R. § 1926.50(g), is
judged on “the ‘totality’ of the relevant ‘circumstances,’
including the nature, strength, and amounts of the corrosive
material . . . ; the configuration of the work area; and the
distance between the area where the corrosive chemicals are
used and the washing facilities,” Atl. Battery Co., 16 BNA
OSHC 2131 (No. 90-1747, 1994). The Secretary thus cannot
satisfy his burden to establish that facilities are unsuitable
“merely by showing that the flushing apparatus is not an
eyewash fountain.” P.J. Spillane Co., 24 BNA OSHC 1253,
1261 (No. 11-0380, 2012) (vacating citation issued to
contractor for eyewash station comprised of hose and eyewash
bottle). Tellingly, although the Commission recognizes an
affirmative infeasibility defense, Kiewit has not alleged that it
was in fact infeasible to provide suitable quick-drenching
facilities here.

     Kiewit next contends that extending the reach of standards
issued under section 6(a) contravenes the procedural
requirements the Congress prescribed for the promulgation of
new construction standards. Its assertion that established
Federal standards could not be made to apply to the

6]. . . . The Secretary shall issue such rule or order if he determines
on the record, after opportunity for an inspection where appropriate
and a hearing, that the proponent of the variance has demonstrated
by a preponderance of the evidence that the conditions, practices,
means, methods, operations, or processes used or proposed to be
used by an employer will provide employment and places of
employment to his employees which are as safe and healthful as
those which would prevail if he complied with the standard.” 29
U.S.C. § 655(d).
                               39
construction industry absent formal rulemaking procedures is
based on language from the Conference Report, setting out the
conferees’ intent “that the Secretary develop health and safety
standards for construction workers . . . pursuant to the
provisions of [the CSA] and that he use the same mechanisms
. . . for the development of health and safety standards for all
the other construction workers newly covered by [the OSH]
Act.” H.R. Rep. No. 91-1765, at 33 (1970) (Conf. Rep.). But
the implication that the Secretary could adopt only those
construction standards issued under the CSA is at odds with the
language of section 6(a), which authorizes the Secretary to
promulgate “any national consensus standard, and any
established Federal standard” as an OSH standard. 29 U.S.C. §
655(a) (emphases added). Indeed, under Kiewit’s reading, the
Secretary would have been unable to adopt any national
consensus standards for the construction industry because such
standards were not issued in accordance with CSA-mandated
procedures. See OSHRC Decision at 1465 (Attwood, Comm’r,
dissenting). This cannot be. Rather, the Conference Report’s
forward-looking language suggests the conferees were
referring to the development of new construction standards, not
the adoption of preexisting standards under section 6(a). A
contrary interpretation would exert incredible tension on
section 6(a)’s plain language.

     Kiewit also claims the OSH Act’s legislative history
evinces congressional intent to preserve established Federal
standards’ industry-based limitations. It relies primarily on the
Report of the Senate Committee on Labor and Public Welfare,
which states that section 6(a) was designed “to establish as
rapidly as possible national occupational safety and health
standards with which industry is familiar.” S. Rep. No. 91-
1282, at 6 (emphasis added). That is, established Federal
standards “have already been subjected to the procedural
scrutiny mandated by the law under which they were issued.”
                                40
Id. Therefore, as Kiewit sees it, the Secretary could not extend
Walsh-Healey standards without rulemaking because the
construction industry neither was familiar with those standards
nor participated in their original promulgation. The
Commission agreed, noting the construction industry would
have “had no reason or incentive to participate in” the
promulgation of the Walsh-Healey standards “because it was
not affected by the rulemaking,” and that “[d]epriving the
construction industry of its ‘opportunity to participate’ in the
rulemaking process is contrary to the OSH Act’s language and
intent.” OSHRC Decision at 1450. This position is facially
appealing but ultimately unavailing.

     Despite the considerable ink spilled by the parties, the
OSH Act’s legislative history remains, at best, unilluminating.
First, interested employers’ participation is not dispositive. It is
undisputed that the adoption of Walsh-Healey standards as
OSH standards extended their protections to all manufacturers
engaged in interstate commerce. However, the newly covered
employers—those without federal contracts—were not subject
to the Walsh-Healey Act and therefore had no more reason to
participate in rulemaking than the construction industry.
Granted, at least some manufacturers were interested and may
have adequately represented the manufacturing industry at
large but this was not a given. Cf. S. Rep. No. 91-1282, at 4
(before standards became mandatory for all employers,
investing in health and safety often put smaller employers at
“competitive disadvantage”). Many employers ended up
subject to standards they had assumed would not apply,
notwithstanding the standards went through “the procedural
scrutiny mandated” by statute. Id. at 6. Thus, the construction
industry’s lack of participation in the promulgation of the
Walsh-Healey standards does not, alone, affect the
reasonableness of the Secretary’s interpretation.
                                41
     Second, although it makes sense that the Congress would
not have intended industry to be blindsided by standards
rapidly promulgated under section 6(a), it is not obvious that
the standards had to have been scrutinized by each specific
industry to which they were to apply or by industry in general.
Indeed, the Senate Report directing that OSH standards be
those “with which industry is familiar,” id., also recognized
that “the chemical and physical hazards which characterize
modern industry are not the problem of . . . a single industry,”
id. at 4, but instead are “truly a national concern,” id., that
should be addressed through “uniformly applied” standards, id.
at 1. It seems reasonable, then, for new OSH standards to cross
industrial boundaries in order to abate the harms associated
with materials that affect both manufacturing and construction
workers. See id. at 3. And the OSH Act’s drafters “were aware
that the then recently-adopted Walsh-Healey standards would
be the primary source of established federal standards for
industrial working conditions covered by the Act.” Gen.
Motors Corp., 9 BNA OSHC 1331, 1336 (No. 79-4478, 1981)
(emphasis added). Indeed, the Secretary testified to the Senate
Subcommittee on Labor that “the Walsh-Healey Public
Contracts Act and its companion legislation” were “[t]he only
Federal [safety and health] laws not confined to a specific
industry.” Occupational Safety and Health Act, 1970:
Hearings on S. 2193 and S. 2788 Before the Subcomm. on
Labor of the S. Comm. on Labor & Public Welfare, 91st Cong.
80 (1970) (statement of George P. Shultz, Secretary of Labor).

     Our view of the legislative history is not altered by the fact
that the House of Representatives rejected a bill proposed by
Representative Dominick Daniels, providing that any
established Federal standard promulgated as an OSH standard
was “not limited to its present area of application,” H.R. 16785,
91st Cong. § 6 (as reported by H. Comm. on Educ. & Labor,
July 9, 1970), in favor of a substitute bill introduced by
                                 42
Representative William Steiger, which contained no such
language, see H.R. 19200, 91st Cong. (1970). The Commission
deemed the adoption of the competing Steiger bill “as further
proof that Congress never intended [Walsh-Healey] standards
to apply to construction employers.” OSHRC Decision at 1453.
This conclusion is far too speculative. Even assuming “[t]he
vote to substitute was a vote on the Daniels bill,” Kiewit Br. 44
(citing Whirlpool Corp. v. Marshall, 445 U.S. 1, 16 & n.23
(1980)), it is far less clear why the Daniels bill lost. There were
many differences between the two bills, chief among them the
“strike with pay” provision in the Daniels bill, which
“encountered stiff opposition in the House.” Whirlpool Corp.,
445 U.S. at 15. In contrast, the language setting the scope of
established Federal standards was not mentioned during the
floor debates. It is therefore an immense leap to derive from the
Daniels bill’s failure any intent to reject a single phrase in a bill
laden with controversial provisions. We decline the invitation
to make this jump.

     Even after considering Kiewit’s myriad arguments made
in dogged pursuit of its petition,17 whether the quick-drenching
provision was properly extended to the construction industry
remains a question with no obvious answer. It is apparent from
our efforts to untangle the mare’s nest that is the OSH Act and
its implementing regulations that the Congress intended some
scope expansion for standards adopted under section 6(a). See
S. Rep. No. 91-1282, at 6 (established Federal standards “may
be made applicable to additional employees who are not under
the protection of such other Federal laws”). Otherwise, the new
OSH standards would continue to cover only the limited swath
of employers subject to preexisting labor laws. But this says
nothing about how far the Secretary could extend established

    17
        All arguments not expressly addressed have nevertheless
been considered and rejected.
                               43
Federal standards without resorting to formal rulemaking. Did
the Congress intend a section 6(a) standard to apply only to
those employers that would have been covered under the
preexisting standard if there were a federal contract, to all
employers within the same industry, or to all employment
where the condition or hazard exists? Our careful review of the
OSH Act’s less-than-pellucid legislative history and the
Secretary’s frequently muddled regulatory efforts has not
clarified matters. “If Congressional intent is unclear after”
analyzing the statute and relevant legislative history, “then the
reviewing court is called upon to determine whether the
agency’s interpretation is ‘permissible,’ that is to say
reasonable.” Inv. Co. Inst. v. Conover, 790 F.2d 925, 932 (D.C.
Cir. 1986).

     Although it is plausible that the Congress intended
standards adopted under section 6(a) to extend only to
employers within the same industry as their source standard,
the Secretary’s interpretation is nevertheless a permissible
construction of the OSH Act. “Step two of Chevron does not
require the best interpretation, only a reasonable one.” Am.
Forest & Paper Ass’n v. FERC, 550 F.3d 1179, 1183 (D.C. Cir.
2008). Considering, among other factors, the OSH Act’s stated
purpose of expanding workplace protections “to assure so far
as possible every working man and woman in the Nation safe
and healthful working conditions,” 29 U.S.C. § 651(b), and
section 6(a)’s instruction that, “[i]n the event of conflict among
any such standards, the Secretary shall promulgate the standard
which assures the greatest protection of the safety or health of
the affected employees,” id. § 655(a), we find that the
Secretary’s interpretation is consistent with the OSH Act and
is therefore entitled to Chevron deference. We do not reach the
Secretary’s arbitrary-and-capricious challenge because the
Commission’s failure to “afford proper deference to the
Secretary’s reasonable determination” necessitates that its
                             44
“ruling was not in accordance with the law” and must be set
aside. Sec’y of Labor v. Cranesville Aggregate Cos., 878 F.3d
25, 36 (2d Cir. 2017).

     Accordingly, we grant the Secretary’s petition for review
and deny Kiewit’s cross-petition, reverse the Commission’s
decision and remand for adjudication on the merits of Kiewit’s
citation.

                                                  So ordered.
