What are PFAS?
Human exposure to per- and polyfluoroalkyl substances (PFAS) is a public health concern that the Centers for Disease Control and Prevention’s (CDC) National Center for Environmental Health (NCEH) and the Agency for Toxic Substances and Disease Registry (ATSDR) are helping our local, territorial, tribal, state, and federal partners address. Over the last decade, interest in PFAS has been growing. ATSDR and our state health partners are investigating exposure to and possible health effects associated with PFAS in more than 30 communities across the United States.
PFAS are man-made chemicals that have been used in industry and consumer products worldwide since the 1950s. They have been used in non-stick 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 breakdown, 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.
Many scientific articles have been published about PFAS exposure and health effects. While it is difficult to show that substances directly cause health conditions in humans, scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals. More research is needed to better understand the health effects of PFAS exposure.
New kinds of PFAS are being developed. Some of these may have properties similar to the existing PFAS, and some may be less persistent in the environment. There are very few scientific studies on new PFAS, so more research is necessary to discover whether they may be a health concern.