## Facts

- The Clean Air Act (CAA) § 112(r) requires EPA to regulate to prevent and mitigate accidental releases of hazardous substances through the Risk Management Program (RMP).
- In January 2017, EPA issued amendments to the RMP commonly called the “Chemical Disaster Rule,” adding accident-prevention, emergency-coordination, and limited public information provisions.
- After promulgation, industry groups petitioned EPA to reconsider portions of the Chemical Disaster Rule.
- EPA issued a “Delay Rule” that postponed the Chemical Disaster Rule’s effective and compliance dates for about 20 months while EPA reconsidered the rule.
- Community organizations, states, and labor organizations challenged the Delay Rule, arguing it unlawfully suspended finalized safety requirements and increased risks to workers and nearby communities.

## Issues

1. Whether the CAA and APA authorized EPA to delay the effective date of a finalized rule for nearly two years based on pending reconsideration.
2. Whether the Delay Rule was arbitrary and capricious because EPA failed to provide a reasoned explanation and failed to account for the safety consequences of postponing the Chemical Disaster Rule.

## Decision

- The D.C. Circuit granted the petitions for review and vacated the Delay Rule.
- The court held EPA lacked statutory authority to impose a broad, extended delay of a finalized rule under general CAA/APA authorities.
- The court separately held the Delay Rule was arbitrary and capricious because EPA did not adequately evaluate the safety benefits of the Chemical Disaster Rule and the risks created by delaying it.
- Vacatur reinstated the Chemical Disaster Rule’s effective timing subject to any later lawful rulemaking.

## Legal Principles

- An agency’s extended postponement of a rule’s effective/compliance dates can operate as a substantive amendment or suspension and therefore requires proper statutory authority and compliance with required procedures.
- General administrative or reconsideration authorities do not permit an agency to nullify the operative effect of a final rule for an extended period absent clear authorization in the governing statute.
- Under APA arbitrary-and-capricious review, an agency must consider important aspects of the problem and provide a reasoned explanation connecting the record to the chosen action; ignoring regulated harms (including safety risks) renders action unlawful.
- Statutory reconsideration mechanisms do not, by themselves, authorize suspending a final rule’s operation; reconsideration may proceed while the existing rule remains in effect unless the statute authorizes a stay.

## Conclusion

The D.C. Circuit vacated EPA’s Delay Rule, ruling that EPA could not suspend a finalized chemical-accident safety rule for nearly two years without statutory authorization and without a reasoned explanation that accounted for the public safety consequences of delay.


Air All. of Hous. v. Env’t Prot. Agency, 906 F.3d 1049 (D.C. Cir. 2018)