Comparison of PFAS: Implications for Hazard, Exposure and Risk Assessment
Per- and polyfluorinated alkyl substances (PFAS) have been and continue to be used in the semi-conductor industry, including in etching and resist materials, polymers used in processing, as well as manufacturing equipment (valves, tanks, and pumps) to ensure the clean environment necessary for electronics manufacture. Some of these chemistries, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are facing regulatory restrictions and/or have been voluntary phased out of manufacture in the United States. In place of these chemistries, alternate PFAS have been developed for use in a wide variety of industries, with a focus on shorter chain compounds thought to be less environmentally and biologically persistent than PFOA and PFOS. The U.S. EPA and state-based environmental agencies have established health-based screening criteria for PFOA, PFOS and a variety of their substitutions. Furthermore, the U.S. EPA has recently released draft assessments of GenX and perfluorobutane sulfonate (PFBS). This presentation will compare physiochemical; fate and transport; and toxicological properties associated with a variety of PFAS, including PFOA and PFOS as well as a many of substitute chemistries, in an effort to understand potential impacts of substitution to human health and the environment.