## Facts

- EPA issued a rule providing that certain recycled industrial byproducts used to make zinc fertilizers, and the resulting fertilizers, would not be regulated as RCRA Subtitle C hazardous wastes if specified handling, storage, and reporting conditions were met and the fertilizer products stayed below contaminant thresholds (including lead, arsenic, mercury, cadmium, chromium, and dioxins).
- Zinc fertilizers may be produced from virgin inputs or from recycled byproducts of industrial processes.
- Before the rule, EPA treated these secondary materials as “solid waste” and, if hazardous, as Subtitle C hazardous waste until converted into a final commercial product.
- The parties agreed the secondary materials were “hazardous” under RCRA; the dispute centered on whether they were “solid waste,” i.e., whether they had been “discarded.”
- Petitioners sought review, arguing EPA unlawfully exempted hazardous wastes from Subtitle C regulation.
- EPA defended its approach as a permissible determination that, under the rule’s conditions, the materials were not “discarded” and that the resulting products were comparable to fertilizers made from virgin materials.
- The court largely sustained the rule but remanded for further explanation of EPA’s selected exemption level for chromium.

## Issues

1. Whether EPA permissibly concluded that recycled byproducts used to make zinc fertilizers, and the resulting fertilizers, are not “solid waste” under RCRA when subject to specified conditions and contaminant limits.
2. Whether EPA’s use of an “identity principle,” economic value/market participation, and required management controls is a lawful basis to distinguish “waste” from “non-waste” under RCRA.
3. Whether EPA adequately explained and supported the contaminant thresholds, particularly the chromium limit, on the administrative record.

## Decision

- The court upheld EPA’s authority to treat the covered recycled inputs and fertilizers as outside Subtitle C where the rule’s conditions and contaminant limits are met.
- The court sustained EPA’s “identity principle,” together with market valuation and required management practices, as a permissible method for determining that the materials were not “discarded.”
- The court denied the petition for review in substantial part.
- The court remanded to EPA for further explanation of the chromium exemption level, affirming the rule in all other respects.

## Legal Principles

- Under RCRA, a material is subject to Subtitle C as “hazardous waste” only if it is both “hazardous” and a “solid waste,” and “solid waste” turns on whether the material has been “discarded.”
- EPA has interpretive discretion, within reasoned bounds, to treat certain materials recycled into commercial products as not “discarded” when conditions ensure controlled recycling and product comparability to virgin-material counterparts.
- EPA may use product identity/comparability, evidence of legitimate market value, and enforceable management practices as indicators that materials are being productively used rather than discarded.
- When an agency’s decision depends on technical risk judgments reflected in the record, it must adequately explain the basis for specific regulatory thresholds; insufficient explanation warrants remand for further agency reasoning on the record.
- Courts may not supply missing agency reasoning; the agency must provide the justification for its action in the first instance.

## Conclusion

The D.C. Circuit largely upheld EPA’s RCRA determination that certain recycled zinc fertilizer materials and products, when managed under specified controls and contaminant limits, need not be treated as Subtitle C hazardous waste, but remanded for EPA to better explain the chosen chromium threshold.


Safe Food & Fertilizer v. EPA, 350 F.3d 1263 (D.C. Cir. 2003)