## Facts

- National Maritime Safety Association (NMSA) is a trade association representing marine-terminal operators.
- OSHA issued a final rule in December 2008 regulating “vertical tandem lifts” (VTLs), a crane operation lifting multiple vertically connected shipping containers in one hoist.
- VTLs had been used in marine-terminal operations for over 20 years; OSHA estimated roughly one million VTLs had occurred since 1986.
- OSHA acknowledged that no injuries had been reported as occurring during a VTL over that period.
- The rule imposed (among other requirements) weight limits for two-container VTLs, prohibited certain container types from VTLs, and required immediate pre-lift equipment inspections, which OSHA recognized could make some ship-to-shore VTLs impractical.
- NMSA petitioned for direct review under 29 U.S.C. § 655(f), arguing OSHA failed to support the standard with substantial evidence and failed to justify regulation based on a “significant risk” finding.

## Issues

1. Whether OSHA adequately found, on the record, that VTL operations posed a “significant risk” of harm sufficient to justify regulation under the OSH Act.
2. Whether OSHA was required to quantify VTL risk numerically, and whether the absence of quantification made the standard unlawful.
3. Whether OSHA failed to meaningfully consider existing industry practices and voluntary standards when assessing baseline risk and the need for additional regulation.

## Decision

- The court granted the petition in part and denied it in part.
- The court held OSHA is not categorically required to quantify risk numerically in every OSH Act rulemaking.
- The court nonetheless required OSHA’s record and explanation to support a finding of “significant risk,” particularly where historical evidence suggests very low incident rates.
- The court vacated and remanded portions of the VTL rule that were not supported by substantial evidence or were insufficiently explained in light of the empirical record and existing practices.
- The court upheld other portions of the rule that were adequately supported by record evidence and agency reasoning.

## Legal Principles

- OSHA must determine, based on evidence and reasoned explanation, that a regulated condition presents a “significant risk” of material harm; conjectural or de minimis risk is insufficient.
- Numerical quantification of risk is not always required, but qualitative risk findings must still be justified by record evidence and a rational explanation connecting facts to regulatory choices.
- Where the record shows extensive historical use with no reported injuries, OSHA must provide a particularly persuasive explanation for any finding that the residual risk is still “significant.”
- Existing voluntary standards and industry practices are relevant to assessing baseline risk and whether additional requirements are “reasonably necessary or appropriate”; OSHA must address them in explaining its regulatory judgment.
- On judicial review, OSHA’s standard must be supported by substantial evidence on the record considered as a whole, and the agency must provide a noncontradictory, adequately explained rationale for key regulatory requirements.

## Conclusion

The D.C. Circuit sustained OSHA’s authority to rely on qualitative significant-risk findings but required those findings to be coherently supported by the record, especially given long-standing VTL use without reported injuries; it therefore vacated and remanded unsupported portions of the VTL standard while leaving other provisions in place.


Nat'l Mar. Safety Ass'n v. Occupational Safety & Health Admin., 649 F.3d 743 (D.C. Cir. 2011)