This regulation amends the existing temporary tolerance exemption for Tobacco mild green mosaic tobamovirus by establishing a permanent exemption from the requirement of a tolerance for residues of Tobacco mild green mosaic tobamovirus strain U2 in or on all commodities of crop groups 17 and 18 when applied as a post-emergent herbicide and used in accordance with label directions and good agricultural practices. Interregional Research Project Number 4 (IR-4) submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an exemption from the requirement of a tolerance. This regulation eliminates the need to establish a maximum permissible level for residues of Tobacco mild green mosaic tobamovirus strain U2 under FFDCA.