Per- and polyfluoroalkyl substances (PFAS) are a large group of manufactured chemicals, not naturally found in the environment, that have been used in products around the world since the 1940s. The class of PFAS chemicals numbers over 5,000 different compounds, two of which are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). The use of PFAS chemicals has been widespread, and they are found in many products such as Teflon, Scotchgard, waterproofing compounds, stain-proofing compounds, paper and cloth coating, waxes, and aqueous film-forming foam used for fighting fires.
Not only is the presence of PFAS in common everyday products ubiquitous, but the significant strength of the carbon-fluorine bond means that the compounds do not biodegrade and remain intact in the environment and in human bodies, causing buildup over time. Thus, they have come to be known as the “forever chemicals.”
PFAS chemicals also move readily through soil, surface water, and groundwater and have contaminated water supplies across the country. Studies have shown persistent PFAS buildup in persons who have been exposed to PFAS by either consumption or other environmental exposures. There is debate regarding the toxicity of PFAS in the human body that is currently developing. In 2012, the so-called C-8 Panel identified a probable link to kidney and testicular cancer, high cholesterol, ulcerative colitis, thyroid disease, and pregnancy-induced hypertension. However, in 2018, a Michigan PFAS Science Panel found that “causality . . . has not yet been established in current scientific literature” and the toxicity debate continues not only in medical and regulatory bodies but also in expansive litigation across the country.
In June 2022, the U.S. Environmental Protection Agency (EPA) issued interim updated drinking water health advisories for PFOA and PFOS that replaced those issued in 2016. The new health advisory reduced the lifetime exposure level from 70 parts per trillion (ppt) to 4 ppt. These health advisories remain in effect until the EPA establishes a National Primary Drinking Water Regulation. Health advisories reflect the EPA’s assessment of health risks of a contaminant based on the best available science and provide advice and information on actions that water systems may take to address contamination for PFAS chemicals. However, they are not regulatory and are not legally enforceable.
Although there are no current legally enforceable federal maximum contaminant levels (MCLs) for PFAS in drinking water, in March 2023, the EPA announced a Proposed PFAS National Drinking Water Regulation MCL of 4 ppt for both PFOA and PFOS. The comment period for the proposed regulation expired on June 1, 2023, and the EPA anticipates promulgating a final regulation in December 2023. If adopted, the regulation will go into effect in 2026 and would require public water systems to monitor for these PFAS, notify the public of the levels of these PFAS, and reduce the levels of these PFAS in drinking water if they exceed the proposed standards.