Today, the U.S. Environmental Protection Agency (EPA) released a pre-publication notice and a fact sheet on draft toxicity assessments for GenX chemicals and perfluorobutane sulfonic acid (PFBS). GenX and PFBS are members of the broader per- and polyfluoroalkyl substances group. • The reference doses provided by EPA reflect an assessment of the hazard posed and dose-response relationship associated with GenX and PFBS but are not a complete characterization of the risk posed. • EPA found that studies show that the liver is sensitive to GenX chemicals, and the kidney and thyroid are sensitive to PFBS. Data suggests that PFBS may be linked to cancer. • EPA proposed both subchronic and chronic toxicity values. Subchronic refers to repeated exposure for more than 30 days, up to approximately 10% of the life span in humans, while chronic reflects lifetime exposure. • The toxicity values proposed are higher than the RfDs EPA used to calculate the PFOS and PFOA drinking water health advisories. EPA will accept public comments on the GenX and PFBS draft toxicity assessments for 60 days after they are published in the Federal Register. AWWA resources on PFAS available to assist utilities include: DrinkTap’s Perfluorinated Compounds page AWWA Perfluorinated Compounds (PFCs) Fact Sheets Other resources include: Interstate Technology Regulatory Council Factsheets The Water Research Foundation Per- and Polyfluoroalkyl Substances: Background Technical Information White Paper Questions can be directed to Steve Via , director of federal relations for AWWA.