What are PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a group of manufactured, highly fluorinated organic compounds that have been used since the 1950s in various industrial processes and in consumer and household products. PFAS are sometimes referred to as ‘forever chemicals’ because they are difficult to break down and can remain in the environment indefinitely.

PFAS have been detected globally in water, soil, people and wildlife. There is growing public concern about PFAS contamination due to its widespread detection, documented toxicity in animals, and epidemiological studies which have indicated possible links to adverse human health impacts.

PFAS are valued for their oil, stain and water-resistant properties and became important in firefighting as a fire retardant called Aqueous Film Forming Foam (AFFF). AFFFs are most commonly deployed at military sites and airports. In addition, PFAS are used in industrial and consumer products to prevent corrosion, reduce friction and make products waterproof and stain-resistant. At present, there are approximately 9,000 known PFAS compounds.

Products containing PFAS represent a wide variety of items including: food packaging, cosmetics, paints, wood treatments, and fabrics. They are also utilized in a number of industrial processes including metal-plating, mining and fracking, textile production, manufacturing of industrial chemicals and plastics, photography, and in the semiconductor industry.

PFOA and PFOS have been the most widely produced and studied of this family of chemicals. They have been used in carpets, clothing, fabrics for furniture, cookware, food packaging and other materials that are designed to resist water, oil or stains. PFOA and PFOS were voluntarily phased out of production in the United States in 2015-2016; however, these chemicals continued to be produced abroad.

This material is based upon work supported under a grant by the Rural Utilities Service, United States Department of Agriculture. Any opinions, findings, and conclusions or recommendations expressed in this material are solely the responsibility of the authors and do not necessarily represent the official views of the Rural Utilities Service.