## Facts

- OSHA promulgated a final respiratory protection standard on January 8, 1998, codified at 29 C.F.R. § 1910.134, following notice-and-comment rulemaking.
- The new rule comprehensively revised requirements governing the manner and conditions of respirator use, including medical evaluation, fit testing, training, maintenance, and program administration.
- A prior respiratory protection approach dating to 1971 included a hierarchy-of-controls concept prioritizing engineering and work-practice controls over respirators, generally limiting respirator use to situations where engineering controls were infeasible or during their implementation.
- OSHA did not reopen or revise the hierarchy-of-controls concept in the 1998 respirator rulemaking, treating it as embedded in exposure-specific substance standards rather than in the general respirator standard.
- Industry petitioners (American Iron and Steel Institute, on behalf of members) and a professional medical group (American College of Occupational and Environmental Medicine) filed consolidated petitions for review under the OSH Act.
- Labor and nursing organizations intervened in support of OSHA.

## Issues

1. Whether OSHA acted unlawfully or arbitrarily by issuing a revised respirator standard without reconsidering, through notice-and-comment, the preexisting hierarchy-of-controls policy that had been adopted earlier under an expedited statutory process.
2. Whether challenged requirements in the 1998 respirator standard were consistent with the OSH Act and supported by substantial evidence, including OSHA’s health, risk, feasibility, and cost determinations.

## Decision

- The court denied all petitions for review and left the 1998 respiratory protection standard in effect.
- OSHA acted within its statutory authority by limiting the rulemaking to the manner and conditions of respirator use and was not required to reopen the hierarchy-of-controls policy.
- The challenged provisions were reasonable, consistent with the OSH Act, and supported by substantial evidence on the record as a whole.

## Legal Principles

- OSHA may define the scope of a particular health-and-safety rulemaking and is not required to re-justify or re-promulgate older standards simply because they relate to the same general subject matter.
- Under the OSH Act, OSHA may base standards on the best available evidence; scientific uncertainty does not invalidate a rule where the agency provides a reasoned explanation grounded in the record.
- Substantial-evidence review is satisfied even when the record could support competing conclusions, so long as OSHA’s choice is supported by substantial evidence on the record as a whole.
- Courts generally defer to OSHA’s technical and scientific judgments regarding workplace health protections and feasibility when the agency explains its decisions and responds to significant comments.

## Conclusion

The Eleventh Circuit upheld OSHA’s 1998 respirator program requirements, concluding that OSHA reasonably confined the rulemaking to operational safeguards for respirator use, had no statutory obligation to reopen the preexisting control hierarchy, and supported its determinations with substantial evidence and reasoned explanations.


Am. Iron & Steel Inst. v. Occupational Safety & Health Admin., 182 F.3d 1261 (11th Cir. 1999)