This regulation establishes tolerances for residues of isofetamid in or on nut, tree, group 14-12, and almond, hulls. Dietary Exposure From Food and Feed UsesIn evaluating dietary exposure to isofetamid, EPA considered exposure under the petitioned-for tolerances as well as all existing isofetamid tolerances in 40 CFR 180.681. No such effects were identified in the toxicological studies for isofetamid therefore, a quantitative acute dietary exposure assessment is unnecessary. The unrefined chronic dietary exposure assessment used tolerance-level residues and assumed 100 percent crop treated (PCT) for all registered and proposed commodities. For the purposes of this tolerance action, therefore, EPA has assumed that isofetamid does not have a common mechanism of toxicity with other substances.