You may have only recently started hearing the term PFAS, but these chemicals have actually been used since the 1950s. PFAS (short for perfluoroalkyl and polyfluoroalkyl substances) are a large group of man-made chemicals found in many everyday products. Items like non-stick cookware, food packaging, stain-resistant clothing, carpets, and even some firefighting foams have contained PFAS.

What makes PFAS different is how long they last. They are made with an extremely strong chemical bond that doesn’t break down easily over time. Because of this, PFAS can remain in the environment — and in water — for many years. That’s why they’re often called “forever chemicals.”

Over time, people and animals can be exposed to small amounts of PFAS through water, food, and everyday products. Because these chemicals do not break down easily, they can build up in the body faster than they are removed. This gradual buildup or bioaccumulation is one reason PFAS have become a growing concern.*

With thousands of variations of PFAS chemicals, research is ongoing — but studies conducted to date have already established important links between PFAS exposure and several serious health concerns:

Immune System Effects: The National Toxicology Program (NTP) concluded that two of the most common PFAS — PFOA and PFOS — suppress antibody response and pose a hazard to immune system function in humans, reducing the body's ability to fight infections.

Cancer Risk: Exposure to certain PFAS has been associated with an increased risk of some cancers, including thyroid cancer.

Metabolic & Hormonal Disruption: PFAS exposure has been linked to altered metabolism, childhood obesity risk, delayed puberty in girls, increased risk of Type 2 diabetes in women, and decreased bone mineral density over time — raising long-term risks of osteoporosis, breast cancer, renal disease, and thyroid disease.

Liver Damage: Large-scale studies in both humans and animals show consistent evidence of liver damage associated with PFAS exposure, with researchers investigating links to the growing epidemic of nonalcoholic fatty liver disease.*

For more information on current PFAS research, visit the National Institute of Environmental Health Sciences (NIEHS)’s PFAS page.