EPN Comments on Draft Toxicity Assessment of GenX Chemicals and PFBS


On November 14, 2018, the EPA announced that it was seeking public input on draft toxicity assessments for hexafluoropropylene oxide dimer acid and its ammonium salt (GenX chemicals) and perfluorobutane sulfonic acid (PFBS) and related compound potassium perfluorobutane sulfonate. GenX and PFBS are members of a larger chemical family of per- and polyfluoroalkyl substances (PFAS), widely used in commercial and industrial products from nonstick cookware to firefighting foam. These chemicals are incredibly difficult to remove once they’ve entered a water supply and contribute to negative effects on human health. For both chemicals, EPA states that it will not address exposure assessments or address the legal, political, social, economic and technical considerations involved in risk management of these chemicals. EPA failed to exercise its authority under the Safe Drinking Water Act (SDWA) to publish drinking water health advisories for unregulated contaminants, which is grossly negligent given the documented presence of these chemicals in drinking water supplies in multiple areas of the country. In addition, EPA used the flawed draft 2018 “Application of Systematic Review in TSCA Risk Evaluations” guidance to evaluate GenX, which EPN found to be inconsistent with best practices in their August 16, 2018, comments. In response, EPN has produced the following comments on the draft human health toxicity assessments for GenX and PFBS.

Read a summary of the comments: Summary of GenX and PFBS Comments

Read the full comments: GenX and PFBS Comments