Reregistration of pesticides under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), is the process by which previously approved pesticides are subjected to current regulatory requirements. upon completion of reregistration activity, a pesticide is either reregistered and remains in commerce or the registrations is canceled and it is removed from commerce. Approximately 600 pesticide active ingredients will ultimately be subjected to reregistration.

Reregistration is the process by which EPA updates older pesticides and improves the basis on which registration was issued to match current requirements. New pesticides registered today undergo a thorough examination and are supported by a large number of studies as described in Agency guidelines. Reregistration applies these tough, current standards to the older pesticides.