This document revokes certain tolerances and tolerance exemptions for residues of the insecticides combustion product gas, ethion, formetanate hydrochloride, nicotine-containing compounds, polyoxyethylene, and tartar emetic; herbicides chlorpropham, cyanazine, and tridiphane; fungicides 1,1,1-trichloroethane and triforine; and the plant regulators cloprop and 4,6-dinitro-o-cresol because these specific tolerances are either no longer needed or are associated with food uses that are no longer current or registered in the United States. Also, EPA is modifying certain ethion tolerances before they expire. Due to comment, EPA is not revoking specific tolerances for the fungicide bitertanol or the fungicide-insecticide dinocap at this time. The regulatory actions in this document contribute toward the Agency's tolerance reassessment requirements of the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408(q), as amended by the Food Quality Protection Act (FQPA) of 1996. By law, EPA is required by August 2006 to reassess the tolerances in existence on August 2, 1996. The regulatory actions in this document pertain to the revocation of 58 tolerances and tolerance exemptions. Because one tolerance was previously reassessed, 57 tolerances/exemptions are counted as reassessed toward the August 2006 review deadline.