## Facts

- The FDA issued a regulation permanently listing the color additive D&C Green No. 5 for use in drugs and cosmetics.
- Glenn M.W. Scott, proceeding pro se, sought judicial review of the regulation under 21 U.S.C. § 371(f)(1), (3).
- D&C Green No. 5 contained minute quantities of p-toluidine as a chemical impurity; p-toluidine is carcinogenic when tested separately and was involved in manufacture of another color additive (D&C Green No. 6).
- The FDA conducted testing required by the Color Additive Amendments of 1960 and found D&C Green No. 5, as a whole, did not cause cancer in test animals.
- Scott filed objections; the FDA stayed the listing, then terminated the stay and confirmed the original permanent listing order.
- Scott filed petitions for review of both the initial and confirmed orders; the Sixth Circuit consolidated the petitions.

## Issues

1. Whether the Delaney Clause bars listing of a color additive when the additive contains a minute amount of a carcinogenic impurity, even though the additive as a whole is not found to induce cancer.
2. Whether the FDA reasonably determined that p-toluidine is not itself a “color additive,” so that its presence as an impurity in D&C Green No. 5 does not trigger the Delaney Clause.

## Decision

- The Sixth Circuit denied the consolidated petitions for review.
- The court upheld the FDA regulation permanently listing D&C Green No. 5.
- The court accepted the FDA’s view that the Delaney Clause inquiry focuses on whether the color additive itself is found to induce cancer.
- The court upheld the FDA’s determination that p-toluidine was not a color additive but a trace impurity, and its presence did not automatically bar listing.

## Legal Principles

- Under the Delaney Clause for color additives, the statutory cancer bar is reasonably applied by asking whether the listed “color additive” is found by the agency to induce cancer, rather than treating any carcinogenic impurity as automatically disqualifying.
- An agency may treat a carcinogenic substance present only in minute quantities as an impurity, rather than as a separate “color additive,” for purposes of determining whether the Delaney Clause applies.
- In reviewing FDA color additive listings under 21 U.S.C. § 371(f), courts will sustain the agency’s scientific findings and statutory interpretations when reasonably supported by required testing and consistent with the regulatory scheme.

## Conclusion

The Sixth Circuit sustained the FDA’s permanent listing of D&C Green No. 5, holding that the Delaney Clause did not require a ban based solely on trace carcinogenic impurity where the additive, as tested and regulated, was not found to induce cancer and the impurity was not treated as a separate color additive.


Scott v. Food & Drug Admin., 728 F.2d 322 (6th Cir. 1984)