PFAS is an acronym that stands for Poly- and perfluoroalkyl substances. PFAS are a class of more than 4,700 different chemicals. Beginning in the 1940’s, PFAS have been used in a variety of industrial products, like stain and water-resistant fabrics, cleaning products, paints, and fire-fighting foams. PFAS are commonly referred to as forever chemicals, because they can take thousands of years to break down. Unfortunately, they are also linked to a wide array of health problems.