Per- and polyfluoroalkyl substances (PFAS) are a large, diverse group of man-made chemical compounds with special water repellent and non-stick properties. Since the 1950s they have been used in a variety of applications including: cookware, food packaging, cosmetics, carpets, fire-fighting products, stain repellents, polishes, paints and coatings. Structurally, PFAS are organofluorine compounds, where multiple fluorine atoms are attached to a carbon atom. A PFAS can be any compound with a perfluorinated methyl group (–CF3) or a perfluorinated methylene group (–CF2–). PFAS compounds can be categorised in various ways and different chemical databases estimate there are between 4700 and 14700 PFAS compounds.
Strong, stable and persistent
The chain of carbon and fluorine atoms confers advantages and disadvantages to PFAS compounds. They are excellent surfactants and form strong interfaces between air and water. They are strongly water repellent and good at breaking up fatty materials, which is why they have been so widely used in consumer goods. However, the carbon-fluorine bond is incredibly stable, even under harsh conditions. PFAS are very resistant to degradation, they can persist for decades. Consequently, they are often called ‘forever compounds’.
We are all exposed to harmful PFAS compounds
Once released into the environment PFAS spread rapidly. They move through soils, contaminate rivers, lakes, seas, drinking water sources and accumulate in fish and wildlife. We can be exposed to PFAS compounds through the food we eat and the water we drink. Additionally, since PFAS are often used in consumer products, they are found frequently in our homes. One studies estimated that 99% of Americans have at least two harmful forms of PFAS in their blood, and the situation is probably similar around the world. In humans even low concentrations of PFAS have been linked to a wide range of health problems. The effects include increased risk of certain types of cancer, reduced ability to fight infections, altered metabolism, decreased fertility, decreased fetal development and increased risk of obesity.