Per- and polyfluoroalkyl substances (PFAS)

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) form a complex group of thousands of chemicals known for their persistence in the environment. The health effects for all the substances are not yet well documented. The best-characterized toxic effects are associated with certain specific compounds, whereas the population is exposed to a complex mixture of PFAS in the environment. For the time being, it may be difficult to link these exposures to precise health effects. Scientific knowledge about PFAS is advancing rapidly. This page (French version) may therefore be updated periodically.

PFAS : Definition and use

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) constitute a complex group of chemicals comprising thousands of fluorinated organic compounds. They are synthetic products, arising exclusively from human activity, and are not found naturally in the environment. The thermal and chemical stability of PFAS makes them highly resistant to degradation and persistent in the environment. They also have special chemical properties. For example, they are soluble in water and lipids (amphiphilic), making them very useful for many industrial and commercial applications. PFAS have been in use since the 1940s for their flame-retardant, stain-resistant, non-stick, emulsifying, and waterproofing properties. As a result, many consumer products contain them.

Products that may contain PFAS include:

  • flame-retardant foams used to extinguish fires;
  • non-stick coatings on cookware (e.g., TeflonTM);
  • food packaging;
  • waterproofing or stain-resistant products used in various textiles (Gore-TexTM, ScotchGardTM, etc.).

PFAS are also used in a wide range of industrial processes, such as molding, metal galvanizing, and polymer synthesis. They are used in many industrial sectors (rubber, plastics, polymers, semiconductors, petrochemicals, aerospace, mining, metallurgy, textiles, printing, construction and materials).


Decision-support logic diagram for the presence of per- and polyfluoroalkyl substances (PFAS) in drinking water

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