The U.S. EPA has released a report on Human Health Toxicity Values for Perfluorobutane Sulfonic Acid (PFBS) and Related Compound Potassium Perfluorobutane Sulfonate (CAS #29420-49-3). PFBS is a member of a larger group of per- and polyfluoroalkyl substances (PFAS). This assessment is part of EPA’s efforts to increase the amount of research and information that is publicly available on chemicals in the PFAS family. It was developed by the U.S. EPA’s Office of Research and Development (ORD) Center for Public Health and Environmental Assessment (CPHEA).