This regulation amends the existing exemption from the requirement of a tolerance for residues of the plant growth regulator, 1,4-dimethylnaphthalene (1,4-DMN) by expanding the current exemption to include all sprouting root and tuber vegetables (EPA Crop Group 01) and all bulb vegetables (EPA Crop Group 03). On behalf of D-I-1-4, Inc., a division of 1,4Group, Inc., Technology Sciences Group, Inc. (TSG) submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting that EPA amend the existing exemption from the requirement of a tolerance for 1,4-DMN. This regulation eliminates the need to establish a maximum permissible level for residues of 1,4-DMN under the FFDCA.