PFAS Toxicology, Risk, and Recent Regulatory Considerations
Dr. Christopher M. Teaf, Institute of Science & Public Affairs, Florida State University
Per- and polyfluoroalkyl substances (PFAS) are a group of complex synthetic chemicals that have been in use since the 1940s. The majority of research, regulation, and toxicity data surrounding this class of chemicals focuses on the two most extensively produced of the nearly 5,000 PFAS compounds, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). PFAS are persistent in the environment, and exhibit desirable surfactant properties. Select PFAS chemicals have been linked to potential human health concerns, though the information is highly variable. Potential environmental sources of PFAS include used manufacturing raw materials, fire training and emergency response; consumer products (e.g., stain resistants and water repellants); and non-stick consumer products. As a result, many PFAS chemicals have been detected in air, soil, and water, though much of the focus surrounding PFAS regulation has involved drinking water. There is currently no federal Maximum Contaminant Level (MCL) for any PFAS chemical in drinking water, though recent (2021) releases from USEPA have indicated that such criteria may be forthcoming. The USEPA has issued a Lifetime Drinking Water Health Advisory of 70 parts per trillion (ppt) for PFOS and PFOA combined, and is reportedly working on toxicity assessments for at least two other PFAS compounds. Media exposure and public pressure surrounding PFAS chemicals have motivated some states to establish their own regulatory criteria (e.g., Notification Levels (NLs), Action Levels (AL), Public Health Goals (PHGs)), although most efforts still address PFOA and PFOS. Concerns with growing numbers of PFAS chemicals being identified are enhanced by a lack of approved, consensus analytical methods for measuring many PFAS in drinking water. Due to variability in toxicity data for PFAS as a group, recent attention is directed at how to approach an extremely large family of compounds. Continued research is necessary to relate the levels of PFAS detected in drinking water to the levels that may be associated with actual human health effects.
Dr. Teaf is a Board-certified toxicologist and risk assessor with over 4 decades of environmental and public health experience specializing in soil, water and air quality, risk assessment, and environmental health issues for metals, radionuclides, petroleum, pesticides, solvents, polyfluorinated compounds (PFAs), particulates, and bacteria/molds. He is Director Emeritus of the Center for Biomedical & Toxicological Research at Florida State University, and Director of Toxicology for Hazardous Substance & Waste Management Research in Tallahassee. Chris has experience with industrial facilities, power facilities, agricultural sites, mining operations, waste management sites, educational institutions, and products in general commerce. He has directed research and taught environmental toxicology and risk assessment at the University level, for the private sector, USEPA, World Health Organization, NATO, ATSDR, and state/local agencies. He serves on editorial boards and as peer reviewer for numerous scientific journals and has testified in many state and federal courts.