## Facts

- OSHA issued the “Control of Hazardous Energy Sources (Lockout/Tagout)” standard to prevent injuries from unexpected energization or start-up during servicing and maintenance of machines.
- The standard broadly applied across industries and required employers to use lockout or tagout procedures to control hazardous energy.
- The OSH Act defines an OSHA “standard” as one “reasonably necessary or appropriate” to provide safe or healthful workplaces. A separate provision requires “most adequately assures, to the extent feasible” standards for “toxic materials or harmful physical agents.”
- OSHA treated the lockout/tagout standard as outside the “toxic materials or harmful physical agents” provision and argued that, for such general safety standards, § 3(8) allowed OSHA to select any feasible level of regulatory stringency.
- Labor unions and industry groups petitioned for review, arguing that OSHA’s reading granted overly broad discretion and raised a nondelegation problem.

## Issues

1. Whether “reasonably necessary or appropriate” in the OSH Act permits OSHA to choose any feasible level of stringency for standards not governed by the Act’s toxic-materials provision.
2. Whether OSHA’s broad interpretation would render the statute an unconstitutional delegation of legislative power, and whether a narrowing construction is required to avoid that result.
3. Whether the lockout/tagout standard was adequately justified under the proper interpretation of the agency’s statutory authority.

## Decision

- The court rejected OSHA’s interpretation that § 3(8) largely reduced to feasibility and permitted open-ended choice among feasible regulatory levels.
- The court construed § 3(8) to require OSHA to find a significant risk of material harm absent regulation and to show that the standard substantially reduces that risk in a way that is reasonably necessary or appropriate.
- Applying constitutional avoidance, the court held that this limiting construction supplied an intelligible principle and avoided a serious nondelegation concern.
- The court upheld portions of the lockout/tagout standard supported by sufficient findings and explanation under the significant-risk/risk-reduction requirement.
- The court remanded other portions for further explanation or justification consistent with the narrowed interpretation.

## Legal Principles

- For OSHA standards issued under § 6(b) but not governed by the Act’s toxic-materials provision, § 3(8) requires more than feasibility; OSHA must identify a significant risk of material harm.
- OSHA must also show that the challenged requirements materially (substantially) reduce the identified significant risk and are reasonably necessary or appropriate to achieve workplace safety.
- Courts may construe broad statutory phrases to avoid serious constitutional questions, including nondelegation concerns, so long as the narrowing construction is fairly supported by the statute’s text and structure.
- A standard’s validity depends on whether OSHA’s record and explanation connect specific regulatory obligations to demonstrated significant hazards and meaningful risk reduction.

## Conclusion

The D.C. Circuit limited OSHA’s discretion under the OSH Act by requiring a significant-risk finding and a demonstration of material risk reduction for general safety standards, thereby avoiding a nondelegation problem; it sustained parts of the lockout/tagout rule and remanded inadequately justified provisions for further agency action.


Int'l Union, United Auto., Aerospace & Agric. Implement Workers of Am., UAW v. Occupational Safety & Health Admin., 938 F.2d 1310 (D.C. Cir. 1991)