On Petition for Review of an Order of the Mine Safety and Health Administration
Before: Ginsburg, Chief Judge, Garland, Circuit Judge,
and Williams, Senior Circuit Judge.
The opinion of the court was delivered by: Ginsburg, Chief Judge
The United Mine Workers of America petitions for review of a final decision of the Mine Safety and Health Administration (MSHA), a component of the Department of Labor, to withdraw its proposed Air Quality rule. The Union argues the agency's action was contrary to the Federal Mine Safety and Health Act of 1977, 30 U.S.C. § 811, and arbitrary and capricious, in violation of the Administrative Procedure Act, 5 U.S.C. § 706(2)(A). Because we conclude the MSHA failed to provide an adequate explanation for its decision, we grant the Union's petition and remand this matter to the agency for further proceedings.
The Mine Safety and Health Act authorizes the Secretary of Labor to promulgate health standards "dealing with toxic materials or harmful physical agents" in order to protect miners from any "material impairment of health or functional capacity." 30 U.S.C. § 811(a)(6)(A). Pursuant to this authority, in 1989 the MSHA proposed a comprehensive rule that would: (1) "establish lists of hazardous substances that may adversely affect health and ... require control of exposure to such substances"; (2) "establish permissible exposure limits [PELs] and delineate the methods and frequency of monitoring to evaluate exposure"; and (3) "revise requirements for respiratory protection programs for metal/nonmetal mines and establish similar requirements for coal mines." Air Quality, Chemical Substances, and Respiratory Protection Standards, Proposed Rule, 54 Fed. Reg. 35760, 35761/2 (Aug. 29, 1989). The rule would have, among other things, established PELs for more than 600 chemical substances that might be present in a mine, 165 of which substances would have been regulated for the first time. See id. at 35766/3, Table 2. As explained in the proposal:
The effect of these substances may range from allergic reactions to systemic toxicity. Some of them are capable of causing cancers, central and peripheral neuropathies, lung disease, liver and kidney damage, birth defects, and other systemic effects.
When it proposed the rule, the MSHA "believe[ed] that the health evidence form[ed] a reasonable basis for proposing revisions to [current exposure] levels." Id. Accordingly, the agency conducted public hearings, solicited and received comments, and in 1994 adopted one phase of the rule. See Air Quality: Health Standards for Abrasive Blasting and Drill Dust Control, Final Rule, 59 Fed. Reg. 8318 (Feb. 18, 1994), codified at 30 C.F.R. §§ 58.610-.620, 72.610-.630; see also Air Quality Proposed Rule, 54 Fed. Reg. at 35776/1-77/1.
In September 2002, however, the MSHA decided to withdraw the remainder of the proposed rule. 67 Fed. Reg. 60611 (Sept. 26, 2002). By way of explanation, the agency said its decision to withdraw the proposed rule "was the result of changes in agency priorities and the possible adverse effect ... of the decision in AFL-CIO et. al. v. OSHA," id. at 60611/2, in which the Eleventh Circuit had invalidated an OSHA rule that set new PELs for 428 toxic substances, see 965 F.2d 962 (1992). The MSHA also noted it had been "more than 13 years since the proposal was published and more than 12 years since the comments were received." 67 Fed. Reg. at 60611/2.
The Union first argues the MSHA's withdrawal of the proposed Air Quality rule was contrary to the Mine Safety and Health Act. We review the MSHA's interpretation of the Act according to the familiar standards in Chevron U.S.A. Inc. v. Natural Resources Def. Council, Inc., 467 U.S. 837, 842-44 (1984). The Union also contends the MSHA's action was arbitrary and capricious, in violation of the Administrative Procedure Act, 5 U.S.C. § 706(2)(A).
We note at the outset that the source of our jurisdiction to entertain the Union's petition, though the parties did not question it, is far from obvious. We therefore raised the issue ourselves and directed the parties to address it at oral argument. See Citizens for Abatement of Aircraft Noise, Inc. v. Metro. Wash. Airports Auth., 917 F.2d 48, 53 (D.C. Cir. 1990) ("a court of appeals must ...