This regulation extends time-limited tolerances for combined residues of the herbicide glufosinate ammonium (butanoic acid, 2-amino- 4-(hydroxymethylphosphinyl)-monoammonium salt and its metabolite, 3- methylphosphinico-propionic acid in or on sweet corn (kernels and cob with husk removed), sweet corn forage, and sweet corn stover at 4.0 part per million (ppm) for forage, kernels and cobs and 6.0 ppm for stover for an additional 2-year period. This tolerance will expire and is revoked on December 31, 2001. This action is in response to EPA's granting of an emergency exemption under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act authorizing use of the pesticide on sweet corn. Section 408(l)(6) of the Federal Food, Drug, and Cosmetic Act requires EPA to establish a time-limited tolerance or exemption from the requirement for a tolerance for pesticide chemical residues in food that will result from the use of a pesticide under an emergency exemption granted by EPA under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act.