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Common PFAS Chemicals

Chemistry of  Common PFAS Chemicals

The term PFAS (per- and polyfluoroalkyl substances) refers to a vast and diverse family of man-made chemicals that share a defining characteristic: carbon atoms where most or all of the carbon bonding sites are strongly attached to fluorine atoms. It’s this unique carbon-fluorine bond that gives PFAS their exceptional stability and resistance to heat, water, and oil. Within this extensive family, PFAS compounds can be categorised into two main groups: polymers and non-polymers.

PFAS Polymers

One significant class of PFAS compounds are fluoropolymers. These are large, complex molecules formed by linking many smaller PFAS units together into long chains. Common examples include:

  • PTFE/Teflon® (Polytetrafluoroethylene): PTFE is famous for its non-stick properties, making it suitable for cookware,  but also crucial in industrial applications for its low friction and chemical resistance.
  • FEP (Fluorinated Ethylene Propylene): Known for its flexibility, clarity, and resistance to chemicals and UV radiation, often used in wiring, tubing, and non-stick coatings.
  • ETFE (Ethylene Tetrafluoroethylene): A strong, durable material often used in architectural applications and as a protective coating.
  • PFA (Perfluoroalkoxy Alkane): Used in linings, tubing, and high-performance applications.

These fluoropolymers share a few key properties:

  • High molecular weight – their large size means they are not easily absorbed by living organisms
  • Extreme stability – once formed into a seal, they are highly stable, insoluble in water and do not break down

PFAS Non-polymers

Non-polymers are smaller, more mobile, bioaccumulate (build up in the bodies of living organisms over time) and are more readily absorbed:

  • Perfluoroalkyl Carboxylic Acids (PFCAs)
  • Perfluoroalkyl Sulfonic Acids (PFSAs)
  • Perfluoroalkyl Ether Carboxylic Acids/Sulfonic Acids (often called “Ether-PFAS” or “GenX chemicals”)
  • Fluorotelomer Alcohols (FTOHs)

These non-polymer PFAS are the ones primarily responsible for the concerns about environmental persistence, bioaccumulation, and direct health effects that are driving much of the current regulatory action and research.

E&OE. This information was gathered by our manufacturing partners. For more information, visit www.dwi.gov.uk.