This regulation establishes tolerances for residues of phosphine resulting from the use of the rodenticide zinc phosphide in or on alfalfa, forage; alfalfa hay; barley, grain; barley, hay; barley, straw; bean, dry, seed; beet, sugar, roots; beet, sugar, tops; potato; timothy, forage; timothy, hay; wheat, forage; wheat, grain; wheat, hay; and wheat, straw. The Interregional Research Project Number 4 (IR-4) requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA), as amended by the Food Quality Protection Act of 1996 (FQPA).