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After years of use in manufactured products, “PFAS”, or per- and polyfluoroalkyl substances, are common in the environment.  Comparatively little is known about most of them, but evidence of the harm that they can do is growing.  Regulation is increasing, and liability is very likely to be on the way.


PFAS comprise a large family of thousands of synthetic chemicals.  They all contain carbon-fluorine bonds which are among the strongest chemical bonds in organic chemistry.

PFAS have unique properties. For instance, they are stable under intense heat. Many of them also act as water or grease repellents.  They have been used to make a very wide range of products over the years in many areas including in aerospace and defence, automotive, textiles, fire-fighting and food processing.

However, the stability that makes them so useful also means that, unlike a lot of chemicals, they resist degradation if they escape into the environment from the places where they are used or from the products into which they are incorporated. Instead, they gradually accumulate.  

Humans could be exposed to them every day from the food they eat, the water they drink and the places they live and visit. This is a problem because PFAS have toxic side effects.  They are linked to cancer, and to reproduction and hormonal problems in humans.

The regulatory response

The response to risk associated with chemical substances usually follows the following pattern:

  • Restricting or eliminating the use of the substance in new products;
  • Removing older products containing the substances from circulation; and
  • Remediating where the substance has escaped into the environment and is causing danger.

In relation to PFAS, a combination of the Stockholm Convention, the EU’s Persistent Organic Pollutants Regulation and the EU’s REACH Regulation (both of which are retained EU law in the UK) control the use of some PFAS in new products/applications, in particular two types of PFAS called (confusingly) “PFOS” and “PFOA”.  Most types of PFAS are not closely regulated for the moment, however.  Furthermore, there have been no serious steps as yet to remove old PFAS containing products (eg waterproof fabrics) from circulation, or for cleaning up the PFAS that has escaped into the environment.

Next steps

Part of the reason why PFAS use and presence in the environment is not being more comprehensively controlled is because we do not yet know enough about it.  Much more information and understanding is required before more comprehensive regulation of PFAS use and PFAS-containing products can be sensibly proposed, and environmental remediation can be undertaken.

This problem is recognised, however.  The Environment Agency reported on the current science on PFAS in the UK in August 2021.

The report acknowledges information gaps and says that the lack of knowledge is a barrier to effective risk management.  However, it also hints that work is now being done in earnest to close these information gaps.

According to the report, a multi phase project to enhance knowledge of source sites is now under way.  Airfields, fire stations, wastewater treatment and landfill are the focus at the moment, along with manufacturing of textiles, leather, carpets, paper, and metal plating.  There is an ongoing program of associated water and other environmental monitoring. 

Liability in the future

Criminal liability

Those who import or manufacture PFAS or PFAS-containing goods, or who use/encounter such things in their work, are likely to be subject to increasing regulation in the future.  Their activities may be restricted or controlled, or even prohibited altogether.  Breach of this regulation will incur criminal penalties.  

Civil Liability

Civil liability for injury or damage for those said to have failed in their duty to prevent contamination with or exposure to PFAS is a possibility.  Those possibly at risk of such liability include manufacturers and importers of PFAS and PFAS-containing goods, and those responsible for sources of release of PFAS into the environment, eg aerodromes, landfill sites and wastewater treatment facilities.

The success of civil liability claims in the UK are very much dependent on, first, being able to fund the claim and, second, being able to overcome key legal hurdles, namely breach of duty, causation, injury/damage and remoteness.  Both are significant obstacles for claimants at the moment, but may become less so depending on how PFAS knowledge develops.

Regulatory Liability

Property where PFAS has been manufactured or used in the past or where PFAS products have been disposed of (including for example, property encompassing or near airfields, fire stations, landfills, and certain forms of manufacturing) may require clean-up at the direction of a regulator if they are contaminated with PFAS.

Until there are clear PFAS-related thresholds established across the board for water pollution and human exposure, it will be difficult for a regulator to routinely make a clear cut case for remediation.  However, the research into what those thresholds might be is ongoing and things are already starting to move.  Benchmarks are starting to be put in place for drinking water which are very low.  Remediation actions are highly likely in future.

As to who would bear responsibility for any remediation, this will depend on a host of issues.  Generally speaking however, alongside historic polluters, current owners are at risk.  They might have accepted all liability from the past owner by way of contract when they bought – even for substances that had not been detected at that point.  Also, any redevelopment of the property by the current owner might have had the effect of channelling liability from all past owners/polluters (this is the consequence of the contaminated land regime rules).

That a “clean” environmental survey is already in existence for a property is not necessarily a comfort.  PFAS has not always been one of the chemical groups tested for.  It may have been missed by the survey.  


If liability trends in the USA are a sound indicator of things to come in the UK, as they so often are, PFAS is an issue.  The PFAS knowledge base is growing all the time in the UK, and with it the prospect or regulation and liability.

This document provides a general summary and is for information/educational purposes only. It is not intended to be comprehensive, nor does it constitute legal advice. Specific legal advice should always be sought before taking or refraining from taking any action.