This regulation establishes tolerances for residues of the herbicide safener, mefenpyr-diethyl (CAS Reg. No. 135590-91-9), also known as 1-(2,4-dichlorophenyl)-4,5-dihydro-5-methyl-1H-pyrazole-3,5- dicarboxylic acid, diethyl ester and its 2,4-dichlorophenyl-pyrazoline metabolites, applied at a rate no greater than 0.053 pounds safener per acre per growing season, in or on the rotational crop commodities soybean seed, soybean hay, soybean forage and canola seed. Bayer CropScience requested these tolerances under the Federal Food, Drug, and Cosmetic Act (FFDCA).