Les v. Reilly

In 1988, the EPA determined that four pesticides were carcinogens, though its own regulations still permitted their use as food additives, despite the Delaney clause of the Federal Food, Drug, and Cosmetic Act barring cancer-causing pesticides as food additives. Kathleen Les and other individuals (plaintiffs) petitioned the EPA to revoke the regulations allowing the pesticides, but the EPA refused, relying on a scientific study to argue that the cancer risk from the four pesticides was de minimis and that recognizing a de minimis exception would allow a more reasonable, realistic approach to minimizing cancer-causing exposure. The plaintiffs petitioned the Ninth Circuit for review of the EPA's final order.