This regulation establishes an exemption from the requirement of a tolerance for residues of thiamine mononitrate (CAS Reg. No. 532- 43-4) when used as an inert ingredient (enzyme cofactor) in pesticide products applied to/on all growing crops pre-harvest, limited to 0.1% (by weight) in pesticide formulations. SciReg, Inc on behalf of Valagro, S.p.A submitted a petition to EPA under the Federal Food, Drug, and Cosmetic Act (FFDCA), requesting an establishment of an exemption from the requirement of a tolerance. This regulation eliminates the need to establish a maximum permissible level for residues of thiamine mononitrate when used in accordance with this exemption. Vitamin B1 is also known as thiamine mononitrate. Throughout this document and for purposes of issuing the tolerance, EPA is using the name "thiamine mononitrate" to be consistent with standard agency nomenclature for the identification of this substance.