Cancelling pesticide registrations and revoking tolerances: The case of chlorpyrifos.

Petitions submitted to the United States Environmental Protection Agency (EPA) have sought to cancel registrations of chlorpyrifos and to revoke chlorpyrifos tolerances in or on food due to adverse health effects on people. Under federal law, tolerances for pesticide chemical residues in or on food must provide with reasonable certainty that no harm will result from a person's aggregate exposure. Petitioners' claims are analyzed under the legal requirements to discern whether the EPA had a rational basis for issuing its 2017 Chlorpyrifos Order denying the requests for cancellation of registrations and revocation of tolerances. The scientific evidence considered by the EPA indicated that existing tolerances do not protect people from unsafe levels of chlorpyrifos. Under the Federal Food, Drug, and Cosmetic Act, tolerances need to be revoked if they do not protect human health. In refusing to recognize that chlorpyrifos tolerances do not comply with federal law, the EPA's 2017 Chlorpyrifos Order appears to be arbitrary and capricious.