Our understanding on the impacts of PFAS in drinking water is limited to a few specific chemicals at present. The most studied PFAS are perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The U.S. Environmental Protection Agency current identifies PFOA as “likely to be a carcinogen” based on findings from rodents. Additional research on PFOA, PFOS, and a handful of other chemicals suggests that non-cancer health effects from both PFOA and perfluorooctanesulfonic acid (PFOS) include liver effects, immunological effects, decreased birth weights, thyroid disease, decreased fertility, and cardiovascular disease.
In 2016, EPA concluded that at a combined concentration of PFOA and PFOS at 70 parts per trillion (ppt) over a lifetime exposure (70 years) negative effects may occur. This spring, EPA is anticipated to revise this level and publish a similar level for two other compounds: hexafluoropropylene dimer acid (GenX) and perfluorobutanesulfonic acid (PFBS).