On Nov. 14, 2018 the U.S. Environmental Protection Agency (EPA) issued a press release seeking public comment on its draft toxicity assessment for GenX chemicals and perfluorobutane sulfonic acid (PFBS), members of a larger group of per- and polyfluoroalkyl substances (PFAS). PFAS are a category of man-made chemicals that have been widely used to make products because of their stain-resistant, waterproof and/or nonstick properties. As described in prior blog posts on Sept. 5, 2018, Aug. 30, 2018, Aug. 29, 2018, and June 25, 2018, EPA has been working on a PFAS Management Plan since earlier this year when it convened a National Summit in May 2018. This latest draft toxicity assessment is part of that effort.

GenX is a trade name for a technology that is used to make high-performance fluoropolymers (e.g., some non-stick coatings) without the use of perfluorooctanoic acid (PFOA). PFBS is a replacement chemical for PFOS, a chemical that was voluntarily phased out by its manufacturers. EPA established health advisories for PFOA and PFOS based on the agency's assessment of peer-reviewed science. This information was provided to drinking water system operators, and state, tribal and local officials who have the primary responsibility for overseeing these systems so they can take the appropriate actions to protect their residents. This has led many states to impose drinking water standards for these chemicals. GenX chemicals are designed to be a less toxic replacement for PFOA and PFOS. Based on this latest draft toxicity assessment by EPA, it appears EPA has made a preliminary determination that GenX chemicals are indeed less toxic, a finding which may be revised based on comments received.

EPA will accept comments for 60 days following publication in the Federal Register, which has not yet occurred. However, a pre-publication Federal Register notice is available on the EPA website. Comments can be submitted to regulations.gov using docket number EPA-HQ-OW-2018-0614.