EPA is updating its data requirements in part 158 of Title 40 in the Code of Federal Regulations for the registration of conventional pesticide products. As scientific understanding of potential hazards posed by pesticides has evolved, some data requirements have been imposed on a case-by-case basis but not codified since 1984. Besides providing the regulated community with clearer and more transparent information, the updated data requirements will enhance the development of health and environmental data to conduct scientifically sound chemical hazard/risk assessments to protect human health and the environment. In a companion final rule also being promulgated today, EPA is making technical changes arising from this final rule.