What Is PFAS?

PFAS, short for perfluoroalkyl and polyfluoroalkyl substances, are a group of manufactured chemicals used in industry and consumer products since the 1940s. The US EPA says there are thousands of them, and the National Institutes of Health puts the number at nearly 15,000, based on the EPA’s chemicals database. They break down very slowly and can build up over time in people, animals and the environment, which is why they are sometimes called forever chemicals.

The EPA says people can be exposed by working in jobs such as firefighting or chemical manufacturing, drinking contaminated water, eating certain foods including fish, swallowing contaminated soil or dust, breathing air that contains PFAS, and using products made with PFAS or packaged in materials that contain them.

On health, the EPA says peer-reviewed studies have shown that exposure to certain levels of PFAS may lead to an increased risk of some cancers, including prostate, kidney and testicular cancers, a reduced immune response including to vaccines, interference with the body’s hormones, and increased cholesterol or risk of obesity. The CDC’s Agency for Toxic Substances and Disease Registry adds that it is difficult to show that substances directly cause health conditions in humans, and that more research is needed.

Sources checked September 15, 2026. Every point below links the page it came from.

The sources behind this answer

  • Government sourceThe EPA describes PFAS as a group of manufactured chemicals used in industry and consumer products since the 1940s, and says there are thousands of different PFAS. US EPA ↗
  • Government sourceThe National Institute of Environmental Health Sciences says PFAS are a group of nearly 15,000 synthetic chemicals, according to the EPA’s CompTox chemicals database. NIEHS, National Institutes of Health ↗
  • Government sourceThe EPA says PFAS break down very slowly and can accumulate over time in people, animals and the environment, and that because of this persistence they are sometimes called forever chemicals. US EPA ↗
  • Government sourceThe EPA says people can be exposed to PFAS through certain jobs, contaminated drinking water, certain foods including fish, contaminated soil or dust, air, and products made with or packaged in materials containing PFAS. US EPA ↗
  • Government sourceThe EPA says peer-reviewed studies have shown exposure to certain levels of PFAS may lead to increased risk of some cancers, reduced immune response including to vaccines, hormone interference, and increased cholesterol or risk of obesity. US EPA ↗
  • Government sourceThe Agency for Toxic Substances and Disease Registry says it is difficult to show substances directly cause health conditions in humans, but studies suggest exposure to some PFAS may be linked to harmful health effects, and more research is needed. ATSDR, CDC ↗
  • Regulatory filingMinnesota law defines PFAS as a class of fluorinated organic chemicals containing at least one fully fluorinated carbon atom. Minnesota Revisor of Statutes ↗

Sources checked September 15, 2026. A brand statement is the company’s own claim, which we report but have not verified. Our grades are model-based estimates, not lab tests.

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