## Facts

- OSHA issued a 1989 air-contaminants standard revising or setting permissible exposure limits (PELs) for 428 workplace substances.
- OSHA grouped the substances into 18 categories based on similar health effects and generally analyzed risk and justification at the group level.
- OSHA relied on the rulemaking record and scientific literature but often did not quantify risk for each substance at existing PELs or explain the basis for each new numerical limit.
- Labor and industry petitioners filed consolidated petitions for review; industry argued OSHA failed to justify lowered PELs, and labor challenged aspects it viewed as insufficiently protective.
- The consolidated petitions were reviewed in the Eleventh Circuit under the Occupational Safety and Health Act’s judicial-review provision.

## Issues

1. Whether OSHA must make substance-specific findings that existing exposure levels present a “significant risk” of material health impairment and that each revised PEL is “reasonably necessary or appropriate” to reduce that risk.
2. Whether OSHA’s generic, group-based approach to revising hundreds of PELs without substance-specific quantitative risk assessment satisfied the statutory requirements as interpreted by controlling Supreme Court precedent.
3. Whether the administrative record and explanations for the adopted PELs were sufficient under arbitrary-and-capricious review.

## Decision

- The court granted the petitions for review in substantial part.
- The court vacated most of the 1989 air-contaminants standard and remanded to OSHA for further proceedings.
- The court held that OSHA’s group-based methodology generally failed to supply the necessary substance-specific significant-risk determinations and record support for many revised PELs.
- The court rejected the view that resource constraints justified dispensing with the required findings and reasoned explanation for particular limits.

## Legal Principles

- Before tightening exposure limits, OSHA must determine—based on the record—that significant risks exist at current exposure levels and can be reduced by the new standard.
- OSHA must support each standard with evidence and reasoning showing that the limit is reasonably necessary or appropriate to reduce a significant risk of material health impairment.
- Grouping methodologies may not substitute for an evidentiary link between each regulated substance’s risk at existing levels and the chosen numerical limit.
- Under arbitrary-and-capricious review, an agency must explain why it selected particular numerical limits and connect those limits to demonstrated (or reasonably estimated) risk reduction.

## Conclusion

The Eleventh Circuit largely invalidated OSHA’s comprehensive 1989 PEL update because the agency did not adequately justify most revised limits with substance-specific significant-risk findings and reasoned explanations grounded in the administrative record.


Am. Fed’n of Lab. & Cong. of Indus. Orgs. v. Occupational Safety & Health Admin., 965 F.2d 962 (11th Cir. 1992)