## Facts

- EPA issued final regulations implementing TSCA § 6(e) to control polychlorinated biphenyls (PCBs), addressing disposal, marking, and limits on manufacture, processing, distribution, and use.
- The regulations (1) defined certain uses as “totally enclosed,” (2) adopted a general regulatory cutoff at concentrations above 50 parts per million (ppm), and (3) authorized continued use of eleven specified non-totally-enclosed PCB uses.
- Environmental Defense Fund (EDF) petitioned for direct review, arguing that EPA’s “totally enclosed” determinations, 50 ppm cutoff, and authorizations for non-totally-enclosed uses conflicted with TSCA and lacked record support.
- EPA and multiple industry intervenors defended the rule; the dispute centered on statutory interpretation and the sufficiency of EPA’s evidentiary and analytical basis.

## Issues

1. Whether EPA lawfully classified certain PCB uses (including transformers, capacitors, and electromagnets) as “totally enclosed” under TSCA § 6(e).
2. Whether EPA could categorically limit the PCB regulatory program to materials with concentrations greater than 50 ppm without adequate statutory and evidentiary justification.
3. Whether EPA adequately supported, under TSCA § 6(e), findings that eleven non-totally-enclosed uses “will not present an unreasonable risk of injury to health or the environment.”

## Decision

- The court granted the petition in substantial part and remanded for further proceedings.
- The court set aside EPA’s “totally enclosed” classification for transformers, capacitors, and electromagnets as unsupported by the rulemaking record and inconsistent with a strict reading of “totally enclosed.”
- The court rejected EPA’s blanket 50 ppm threshold as inadequately explained and not sufficiently justified as a categorical exclusion from the TSCA § 6(e) program.
- The court vacated or remanded the authorizations for eleven non-totally-enclosed uses because EPA had not adequately supported “no unreasonable risk” findings for those uses.

## Legal Principles

- Under TSCA § 6(e), “totally enclosed manner” is a narrow category requiring a showing that PCB containment prevents meaningful exposure; EPA must support such classifications with record evidence addressing leakage, emissions, and likely release scenarios.
- EPA may not adopt broad exemptions or categorical exclusions (including concentration cutoffs) without a reasoned explanation grounded in the statute and supported by substantial evidence in the rulemaking record.
- Authorization of non-totally-enclosed PCB uses requires a use-specific “unreasonable risk” determination supported by analysis rather than conclusory or generalized assumptions.
- Even where scientific and technical judgments are involved, judicial review under administrative law requires that EPA’s decisions be lawful, evidence-based, and adequately explained.

## Conclusion

The D.C. Circuit required EPA to reassess major elements of its PCB regulations under TSCA § 6(e), holding that the agency’s “totally enclosed” determinations, 50 ppm cutoff, and several non-totally-enclosed authorizations lacked adequate statutory justification and record support and therefore could not stand without further rulemaking.


Environmental Defense Fund, Inc. v. EPA, 636 F.2d 1267 (D.C. Cir. 1980)