EPA is revoking certain tolerances for the plant growth regulator p-chlorophenoxyacetic acid and the herbicide hexazinone. Also, EPA is modifying certain tolerances for the plant growth regulator p-chlorophenoxyacetic acid and the herbicides glyphosate, difenzoquat, and hexazinone. In addition, EPA is establishing new tolerances for the herbicides difenzoquat and hexazinone.