## Facts

- Consumer and public-interest plaintiffs challenged FDA’s regulation of unavoidable food contaminants, focusing on aflatoxins in corn.
- FDA used informal “action levels” indicating contamination thresholds that would trigger enforcement attention.
- Plaintiffs contended the FDCA required FDA to set formal tolerances and, separately, that the action levels were invalid under the APA because they were issued without notice-and-comment.
- Plaintiffs also challenged FDA’s practice of allowing contaminated corn to be blended with uncontaminated corn to bring the final product within the action level, arguing this violated the FDCA’s adulteration provisions.
- The district court granted summary judgment to FDA on all claims.
- After Supreme Court review rejected the claim that the FDCA always required formal tolerances, the case returned to the D.C. Circuit to resolve the reserved APA and blending issues.

## Issues

1. Whether FDA’s aflatoxin “action levels” operated as legislative rules requiring APA notice-and-comment, rather than as interpretive rules or policy statements exempt from those procedures.
2. Whether FDA’s choice not to take enforcement action against properly blended corn was reviewable and, if so, unlawful under the FDCA.

## Decision

- The court held that the aflatoxin action levels functioned as legislative rules and therefore were procedurally invalid absent APA notice-and-comment rulemaking.
- The court held that FDA’s nonenforcement approach toward blended corn was an exercise of enforcement discretion and was not subject to judicial review.
- The court affirmed in part and reversed in part the district court’s judgment.

## Legal Principles

- A purported “guidance” is a legislative rule under the APA when, in operation, it has present, binding effect on regulated parties and constrains the agency’s enforcement discretion.
- Features indicating a legislative rule include: use of definitive language, treating compliance as effectively safe from enforcement, treating exceedances as presumptive violations, and requiring regulated parties to seek exceptions to depart from the stated levels.
- Legislative rules generally must be promulgated through APA notice-and-comment procedures.
- Agency decisions not to initiate enforcement actions are presumptively unreviewable, especially where the governing statute supplies no judicially manageable standard (“no law to apply”) for evaluating the nonenforcement choice.

## Conclusion

The D.C. Circuit required FDA to use notice-and-comment rulemaking when contamination “action levels” operate as binding regulatory ceilings, but it declined to review FDA’s decision not to pursue enforcement against corn that was blended to fall within those levels.


Cmty. Nutrition Inst. v. Young, 818 F.2d 943 (D.C. Cir. 1987)