What are PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a family of chemicals and can be found in all sorts of products, in the environment and in our bodies. 

PFAS  are man-made substances created by replacing hydrogen atoms (the natural bonding partner for carbon) with fluorine atoms.  This gives PFAS water and oil repellent properties. These properties are sought after in many industrial production processes but come at a cost: the fluorinated parts of emitted PFAS are not degradable. This means that once released into the environment, these PFAS cannot be broken down into carbon dioxide or methane by bacteria, enzymes, or sunlight, earning them the name of  ‘forever chemicals.

Why PFAS are so difficult to regulate

Thousands of PFAS have been described. Hundreds of PFAS are produced industrially. Around 100,000 sites in Europe are estimated to emit PFAS into the environment. Adding complexity to the issue of PFAS contamination, not all PFAS are equal. The non-fluorinated parts of emitted PFAS do in fact degrade. The PFAS found in the environment are therefore not necessarily identical to the ones that companies produce; from the moment they are emitted to the moment they are found in the environment, these PFAS may undergo changes that effectively make them ‘new PFAS’, distinct from their original form. This makes it more challenging for regulators to properly regulate them.


‘Default’ hydrocarbon and partially fluorinated counterpart: octan-1-ol (left) and 6:2 fluorotelomer alcohol (middle), which degrades into PFHxA (right) and into other persistent substances.  

PFAS Molecules

While some PFAS bioaccumulate, building up in ecosystems - including in humans - other PFAS are very mobile and easily travel to any part of the globe. They have the  ability to dissolve in water (but not disappear). Yet others can be volatile and become airborne. Therefore, they  easily transit to other parts of the ecosystem through water and air. 

Many PFAS are toxic with harmful effects on humans and nature. In the case of humans these effects can  take the form of cancer, a weakened immune system and high cholesterol, among others.  

Unnoticed pollution problems  

Major water pollution scandals have hit most production locations, overshadowing a more holistic approach that would include other pollution pathways. 

PFAS life cycle

Key legislative developments

C8 and ‘longer PFAS’ (‘8’ and ‘longer’ refer to the number of consecutive fluorinated carbon atoms) were largely phased out years ago. C6 PFAS are currently the focus of a REACH restriction. Another REACH restriction, covering all remaining PFAS (including C4, fluoropolymers, fluorinated polyethers and F-gases), is being prepared by five EU Member states. This is encouraging but not enough.

Around the world, key developments on PFAS include the following:  

META Articles on PFAS

Useful links:

Videos on PFAS

The recordings of the third series of webinars on Europe’s PFAS problem: situation briefings by independent experts are available at this link.



Image Credits: ID 78668529 © Andrew Mihailovsky

Library for PFAS