USA - EPA Begins Five Chemical Risk Evaluations Under Toxic Substances Control Act, Starts Process for the Next Five Chemicals

​U.S. Environmental Protection Agency announced that it will formally designate five known or probable carcinogens as High-Priority Substances (HPS) that will undergo a risk evaluation under the nation’s chemical safety law, the Toxic Substances Control Act (TSCA): acetaldehyde, acrylonitrile, benzenamine, 4,4’-methylene bis(2-chloroaniline) (MBOCA) and vinyl chloride. EPA also announced the beginning of the 9- to 12-month statutory process to prioritize the next five chemicals under TSCA to determine whether to initiate risk evaluations on them: benzene, ethylbenzene, naphthalene, styrene and 4-tert-octylphenol.​​

EPA began the prioritization process for acetaldehyde, acrylonitrile, benzenamine, 4,4’-methylene bis(2-chloroaniline) (MBOCA) and vinyl chloride in the December 2023 announcement. Today’s final designation of each chemical for risk evaluation is the last step in the 9- to 12-monthlong statutory prioritization process.​​​