PFAS are per- or polyfluorinated alkyl substances that are used as surface-active agents in the manufacture of a variety of products, such as firefighting foams, coating additives (e.g., nonstick pots and pans); textiles (waterproof clothing, stain resistant carpeting); and cleaning products. They are extremely resistant to breakdown in the environment and are found throughout the world in in soil, air, groundwater, municipal refuse, and landfill leachates. Two of the most common PFAS are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).
