What is PFAS?

PFAS are man-made chemicals that have been used in industry and consumer products worldwide since the 1940s. They have been used to make nonstick cookware, water-repellent clothing, stain resistant fabrics and carpets, some cosmetics, some firefighting foams, and products that resist grease, water, and oil.

The most commonly studied PFAS are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS). The next most commonly studied are perfluorohexane sulfonic acid (PFHxS), and perfluorononanoic acid (PFNA). PFOA and PFOS have been phased out of production and use in the United States, but other countries may still manufacture and use them.

During production and use, PFAS can migrate into the soil, water, and air. Most PFAS (including PFOA and PFOS) do not break down, so they remain in the environment. Because of their widespread use and their persistence in the environment, PFAS are found in the blood of people and animals all over the world and are present at low levels in a variety of food products and in the environment. Some PFAS can build up in people and animals with repeated exposure over time.