EPA is revoking certain tolerances for the insecticides amitraz and lindane; the herbicides atrazine, propachlor, and simazine; the plant growth regulator ethephon; and the fungicide ferbam. Also, EPA is modifying certain tolerances for the herbicide atrazine, propachlor, and simazine; the insecticide amitraz; the plant growth regulator ethephon; and the fungicide ferbam. In addition, EPA is establishing new tolerances for the herbicide atrazine and the plant growth regulator ethephon. The regulatory actions finalized in this document are in follow-up to the Agency's reregistration program under the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and tolerance reassessment program under the Federal Food, Drug, and Cosmetic Act (FFDCA) section 408(q).