Per- and poly-fluoralkyl substances (PFAS), known as "forever chemicals" due to their persistence in the environment, have been manufactured and used in a variety of industries for nearly 80 years. Following decades of concerns with human health effects and environmental contamination, the U.S. Environmental Protection Agency (EPA) laid out its PFAS Strategic Roadmap: EPA's Commitments to Action 2021-2024 (PFAS Roadmap) and emphasized the need to ensure science-based decision-making. See PFAS Strategic Roadmap: EPA's Commitments to Action, 2021-2024, at 7 (October 2021) //www.epa.gov/system/files/documents/2021-10/pfas-roadmap_final-508.pdf. As the EPA notes: "Regulatory development, either at the state or federal level, would greatly benefit from a deeper scientific understanding of the exposure pathways, toxicities, and potential health impact of less-studied PFAS." The most researched of the tens of thousands of PFAS are PFOA and PFOS, so the EPA's initial regulatory efforts focused on those two compounds. But, as described below, the regulations developed under the EPA's PFAS Roadmap go beyond PFOA and PFOS, inviting scrutiny by the public, regulated entities, and various stakeholders.

PFAS are a group of manmade chemicals identified by chains of extremely durable fluorine and carbon bonds that have been manufactured and used in the United States since the 1940s. While the PFAS family of chemicals includes the more commonly known and used PFOA, PFOS, and GenX, thousands of additional compounds are also classified as PFAS. Because of their useful properties, including their resistance to heat, water, oil, and stains, PFAS have been utilized in many different industries and incorporated into numerous consumer products over the years. Examples include firefighting foam (known as AFFF), roofing materials, coatings, stain-resistant carpets, water-resistant outdoor clothing and gear, food packaging, nonstick cookware, and personal care products, among others. Unfortunately, PFAS do not degrade via normal chemical, physical, or biological processes, and depending on the type, may build up in people, animals, and the environment over time. Decades of PFAS production and use on a vast scale have resulted in releases to the environment, and these chemicals can now be found in water, soil, air, and food as well as common materials found in homes and workplaces.