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Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals, including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), with high thermal and chemical stability, long-distance transportation ability, and potential for accumulation in the food chain and human body. Due to their oil and water-resistant properties, PFAS have been used in hundreds of industrial applications and products worldwide since the 1950s. They are found in firefighting foams, protective or stain resistant coatings for fabrics and carpets, paper coatings, food paper wrappings, insecticide formulations, paints, cosmetics, and products that resist oil, grease and water.

Per- and polyfluoroalkyl substances (PFAS) are a large group of man-made chemicals that may have negative health effects. You may be exposed to these chemicals from eating or drinking food or water with these compounds. The most is known about the health effects of two PFAS - perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS)- but other PFAS may have similar adverse effects in humans. As new studies become available, our understanding of the health effects of these compounds in humans will continue to grow and we will continue to update this page.

The potential health effects of these substances depend on how much you are exposed to (eat and drink), how long you are exposed, and personal factors including age, lifestyle and overall health. The healthiest thing you can do is lower your exposure to these compounds. For example, if exposure is through drinking water from a private well, consider using other sources of drinking water or installing a treatment system.

The relationship between exposure to PFAS and health effects in people is still being studied. Much of the knowledge about PFAS comes from animal studies, however, humans and animals process these chemicals differently, so more research is needed to fully understand potential health effects. Scientists are still learning about the health effects of exposures to mixtures of different PFAS. The health effects of four PFAS- PFOS, PFOA, PFHxS and PFNA- have been most widely studied. According to the Centers for Disease Control and Prevention (CDC), some but not all studies in humans have shown that exposure to certain PFAS may:

  • affect growth, learning, and behavior of infants and older children
  • lower a woman's chance of getting pregnant
  • interfere with the body's natural hormones
  • increase cholesterol levels
  • affect the immune system
  • increase the risk of cancer

Health Effects for Children


Infants may be at higher risk of health problems because they drink much more water compared to their body weight than older people. While what we know about the health effects in children is limited, certain PFAS may affect growth, learning and behavior of infants and children.

Removing these compounds from water


Certain treatments can remove these compounds from drinking water. Per- and polyfluoroalkyl substances (PFAS) are not removed from water by boiling. Learn more about drinking water treatment for private wells.

Testing for these compounds in private well drinking water


At this time, only a small number of laboratories in the US are approved, by the U.S. Environmental Protection Agency (EPA), to test for PFAS, such as PFOA and PFOS using EPA method 537.1 Learn more about testing your private well water for PFAS.

People served by a community water system (or municipal water supply) should contact their local water authority with questions about PFCs or PFAS in their drinking water.

If you are a physician and there is a concern about PFCs, the first response should focus on minimizing exposures and treating symptoms.

These resources are available to medical professionals:



Information on this section updated January 2020.