This regulation amends 40 CFR 180.940(a), the exemption from the requirement of a tolerance for residues of Quaternary Ammonium Compounds, di-n-Alkyl (C<INF>8</INF>-<INF>10</INF>) dimethyl ammonium chloride, average molecular weight (in amu) 332 to 361 on food contact surfaces when applied/used in public eating places, dairy processing equipment, and food-processing equipment and utensils by increasing the allowable use solution concentrations of quaternary compounds. Lonza Inc. submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act requesting an increase in the concentrations of quaternary compounds in end-use products eligible for the exemption. As amended, the regulation will exempt solutions from the requirement of a tolerance residues resulting from contact with surfaces treated with solutions where the end use concentration of the specific quaternary compounds does not exceed 240 parts per million (ppm) of active quaternary ammonium compounds, and the end-use concentration of all quaternary chemicals in the solution does not exceed 400 ppm of active quaternary compound.