This regulation establishes a time-limited tolerance for the combined residues (free and bound) of the herbicide s-metolachlor [(S)- 2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1- methylethyl)acetamide], its R-enantiomer and its metabolites, determined as the derivatives, 2-[(2-ethyl-6-methylphenyl)amino]-1- propanol and 4-(2-ethyl-6-methylphenyl)-2-hydroxy-5-methyl-3- morpholinone, each expressed as the parent compound in or on sweet potatoes. This action is in response to EPA's granting of an emergency exemption under section 18 of the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) authorizing use of the pesticide on sweet potatoes. This regulation establishes a maximum permissible level for residues of s-metolachlor in this food commodity. The tolerance will expire and is revoked on December 31, 2004. Although the exemption was granted for the active ingredient s-metolachlor and the time-limited tolerance is being set for s-metolachlor, the Agency has determined that residues of concern for s-metolachlor are the same as those for metolachlor, and therefore, the tolerance is being included under 40 CFR 180.368 but under its own section in paragraph (b). Metabolites of metolachlor are assumed to be toxicologically equivalent to parent metolachlor. The Agency has determined that the residues of concern for plant and animal commodities are metolachlor and its metabolites, determined as the derivatives CGA-37913 and CGA-49751.