First published in the Fire Protection Association Journal May 2024
This article was originally published in June 2024 and has been updated for 2025

Per- and Poly-fluoroalkyl Substances (PFAS) entered mainstream public consciousness with the release of the Hollywood film Dark Waters. Following their formulation in the 1930s,^[1]https://pfas-1.itrcweb.org/wp-content/uploads/2020/10/history_and_use_508_2020Aug_Final.pdf their exceptional chemical and thermal stability, as well as resistance to water and oil, saw them incorporated into a plethora of applications in various industries such as manufacturing, firefighting and even household products. However, the very chemical characteristics that resulted in their rapid and widespread use, have led to their pervasive environmental presence within air, water and soil across the globe. Here, we discuss why PFAS are of concern, their regulation and some of the types of legal cases that are arising. 

What are PFAS, and why are they of concern? 

PFAS, sometimes called “forever chemicals”, are a diverse and extensive group of over 12,000^[2]https://www.claire.co.uk/home/news/1782-pfas-bulletin synthetic fluorinated organic chemicals, which exhibit significant variation in their environmental behaviour and toxicity. Few have been studied in detail, however, they all share a common structural feature: a fluorinated carbon chain that can be either fully (per) or partially (poly) fluorinated. These carbon-fluorine bonds are the strongest known in organic chemistry, and impart the useful physical and chemical characteristics.  

Each year, over a megaton of PFAS is produced worldwide. Throughout their manufacture, use, and disposal, they are released into the air and water, leading to their global spread. Volatile PFAS and those attached to airborne particles can travel long distances through the atmosphere, eventually settling on soils and entering water bodies. This results in widespread PFAS contamination at significant ambient and point source concentrations across various environmental settings, and every day, news articles announce previously unknown detections of PFAS in drinking water supplies, or identify new consumer products as potential sources. 

Due to this widespread distribution, concerns about human and environmental exposure to PFAS are rising globally. They have a range of both known and suspected adverse human health effects, and have a damaging and lasting impact on ecosystems. A recent study, which is likely an underestimate, predicts the health-related costs from PFAS across Europe to be EUR 52-84 billion annually^[3]https://www.ricardo.com/media/jrqolnhf/pfas-restriction-proposal-ricardo-version.pdf Indeed, many studies have suggested their slow elimination from the body (years), and links to a variety of health issues, including high cholesterol, ulcerative colitis, thyroid disease, kidney and testicular cancer, and pregnancy-induced hypertension.^[4]https://www.bbc.co.uk/news/science-environment-60761972^[5] https://www.cdc.gov/biomonitoring/PFAS_BiomonitoringSummary.html Among all the PFAS species, Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA) are two of the most discussed and researched, owing to both their abundance of production and use,^[6]https://www.epa.gov/pfas/our-current-understanding-human-health-and-environmental-risks-pfas and recent classification in Europe as carcinogens.^[7]https://www.iarc.who.int/news-events/iarc-monographs-evaluate-the-carcinogenicity-of-perfluorooctanoic-acid-pfoa-and-perfluorooctanesulfonic-acid-pfos/

With growing public concern, improvements in scientific understanding and mounting evidence of health implications, PFAS is increasingly becoming the focus of ever closer regulatory scrutiny. 

The Regulation of PFAS 

The global position on PFAS regulation is developing rapidly. In the early 2000s, concerns over PFOS and PFOA were raised, with the USEPA introducing measures to phase out their production, review alternatives and introduce substitutions by 2015.^[8]https://copilot.cloud.microsoft/?fromcode=cmc&redirectid=9785A85857154D439336E66C4DD96550&auth=2 In many cases, this prompted their replacement with shorter-chain alternatives believed to be less persistent and bioaccumulative, such as perfluorobutane sulfonic acid (PFBS) and perfluorohexanoic acid (PFHxA), as well as what are referred to as GenX chemicals (hexafluoropropylene oxide dimer acid and its ammonium salt).^[9]EPA’s Final Human Health Toxicity Assessment for PFAS GenX Chemicals | Insights | Vinson & Elkins LLP Many of these were subsequently incorporated into industrial and consumer products.^[10]EPA’s Final Human Health Toxicity Assessment for PFAS GenX Chemicals | Insights | Vinson & Elkins LLP However, despite the intention to reduce environmental and health risks, some substitutes for PFOS and PFOA have been found be similarly highly persistent and mobile in the environment, bioaccumulating within food crops such as fruit.^[11]Blaine, A.C., Rich, C.D., Sedlacko, E.M., Hyland, K.C., Stushnoff, C., Dickenson, E.R., Higgins, C.P. 2014. Perfluoroalkyl acid uptake in lettuce (Lactuca sativa) and … Continue reading Furthermore, various of these poly-fluorinated substitutions are now known to biotransform (breakdown) into per-fluorinated compounds, including the notorious PFOS and PFOA,^[12]https://www.claire.co.uk/home/news/1155-cl-aire-publishes-new-technical-bulletin-tb19-pfass thereby unintentionally creating secondary long-term sources. This has led to what is known as ‘regrettable substitution.’ 

On 10^th April, 2024, the US EPA announced drinking water standards for six PFAS to prevent exposure via drinking water for around 100 million people, aimed at preventing thousands of deaths, and reducing tens of thousands of severe illnesses attributable to PFAS.^[13]https://www.epa.gov/sdwa/and-polyfluoroalkyl-substances-pfas Non-enforceable Maximum Contaminant Level Goals (MCLGs) for these PFAS have been set at zero in drinking waters for PFOS and PFOA. Enforceable levels at just 4.0 parts per trillion (ppt) for these two species have also been set^[14]https://copilot.cloud.microsoft/?fromcode=cmc&redirectid=9785A85857154D439336E66C4DD96550&auth=2 These are incredibly low concentrations when seeking to monitor, assess, and remediate with costs envisaged in the billions of dollars. In addition, the EPA announced measures to place accountability for cleanup on parties that have released certain categories of PFAS into the environment, including manufacturers and certain users of PFAS. In the European Union, a very small group of PFAS are already regulated. However, the European Chemicals Agency (ECHA) is presently considering thousands of responses to a 2023 consultation on widespread restrictions on the use of PFAS in Europe. Of specific interest to the ECHA is a proposed restriction of PFAS in various products, including firefighting foams, textiles, and food packaging. Industry will be closely watching the next announcements. As of November 2024, the ECHA and five European countries have issued a progress update on the PFAS restriction process, indicating that they are evaluating over 5,600 scientific and technical comments received during the consultation.^[15]https://echa.europa.eu/-/echa-and-five-european-countries-issue-progress-update-on-pfas-restriction

In the UK, the regulatory picture is fragmented and, following Brexit, is not legally bound to follow the path of the European Union. Nonetheless, regulation of PFAS is expected to increase in volume in coming years. The Health and Safety Executive (HSE) launched a call for evidence on the use of PFAS in consumer products on 4 April 2024, which closed on 4 June 2024. The output from this call for evidence is currently being reviewed, and as of November 2024, the HSE, along with the Environment Agency, are in the process of preparing a regulatory management options analysis (RMOA) for PFAS.^[16]https://consultations.hse.gov.uk/crd-reach/pfas-rmoa-001/ This analysis will investigate the risks posed by PFAS in various consumer products and recommend the best approach to protect human health and the environment. Further updates on potential restrictions are expected in early 2025, as the agencies finalise their assessments and propose regulatory measures based on the evidence collected.^[17]https://consultations.hse.gov.uk/crd-reach/pfas-rmoa-001/

How is PFAS litigation developing? 

Many will be familiar with class actions as a feature of the US legal system, allowing individual claimants to bring legal proceedings as a group. A large proportion of PFAS-related claims brought in the US are class actions. Over 6,400 PFAS-related lawsuits have been filed globally between July 2005 and March 2022^[18]Companies Face Billions in Damages as PFAS Lawsuits Flood Courts and numbers are rising. 

Historically, the legal systems in Europe and the UK have been less geared towards class actions (which are also commonly known as collective actions). However, the cost of litigation often creates a barrier for would-be claimants, and legislators are increasingly searching for ways to make the process more cost effective. One way of doing this is to allow claimants to benefit from the cost savings which can come from litigating as a group. Union-wide laws have been introduced to ensure national legal systems facilitate these types of claims. 

Although not yet reaching the scale of litigation seen in the US, PFAS related claims have been brought in several European member states, including Sweden, the Netherlands, France and Belgium, by residents alleging contamination caused by industrial facilities using PFAS. Furthermore, the number of sites identified as being contaminated, or possibly, contaminated by PFAS is growing throughout Europe.^[19]Cross-cutting story 3: PFAS — European Environment Agency^[20]The Forever Pollution Project – Journalists tracking PFAS across Europe

Many commentators expect that the trend towards PFAS litigation seen in the US and Europe will be reflected in the UK over the coming years. This is, in part, due to growing public and media interest in PFAS, coupled with increased focus on the topic from various regulators. Additionally, a number of recent judicial decisions have had the effect of widening access to collective redress mechanisms, a trend which is expected to continue. 

The litigation funding market is likely also to play a part in the development of the PFAS claims landscape in the UK. Some claimant law firms fund collective actions through the use of conditional fee agreements (also known as no-win-no-fee arrangements) whereby some or all of the firm’s fee is payable only following a successful outcome. Claimant firms often advertise upcoming claims, including through social media, which allows claimants quickly and conveniently join to group proceedings. 

Specialist litigation funders may also be engaged to fund the up-front costs of litigation, in return for a fee if the claim succeeds. In general, environmental claims, including claims related to PFAS, are expected to be a growth area for litigation funders in coming years and this, in turn, is likely to fuel an increase in such claims. 

Claims in relation to PFAS contamination will be far from straightforward with many evidential and legal challenges. Establishing a causative link between PFAS and harm suffered is likely to prove difficult for claimants, due to the diversity of PFAS substances and lacking research. Establishing harm in individual cases is likely to be problematic.  

What action should businesses/organisations be taking? 

There are a number of steps that can be taken to understand PFAS risk positions, and to prepare for future change. 

First, industries that currently use PFAS should map their risks, by keeping a record of which PFAS are being used in their supply chains. This can prove challenging, because the class of chemicals is large and naming conventions vary, but it allows planning for future regulatory change and reduces the risk of inadvertent breaches of new rules. Supply chain disruption can also be anticipated and mitigated in advance. 

PFAS risk assessments should be integrated into due diligence programmes for commercial transactions, such as a mergers and acquisitions. Existing contractual arrangements should be checked for apportionment of risk and amended where possible. 

While many insurance policies now feature exclusions for PFAS risk, specialist coverage may still be available in some markets. Existing and historic policies should be carefully checked and brokers engaged to obtain the most effective coverage for the future. 

Finally, early engagement with legislators and regulators is key. Industry is fighting for the attention of decision makers on many new and emerging issues. Stakeholders stand the best possible chance of having their views heard if a dialogue is opened and maintained when changes are first proposed. This can prove much more challenging if feedback is provided only late in the day, such as when new legislation has been drafted. 

For more information about how HKA can help decode the complexity of PFAS related claims, contact AlexLee@HKA.com. To learn more about HKA visit https://www.hka.com/  

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About the Authors

Alex Lee (MSc, PhD, FGS, CSci, CGeol, EuGeol, ASoBRA, SiLC), Principal 
​​Dr Alex Lee​ has over 25 years of experience in ground risk and remediation. He is a Chartered Geologist and Scientist and a Specialist in Land Condition (SiLC). He is a critical thinker and industry leader with a history of influencing and writing UK guidance. He has been cross-examined in litigation and regularly provides expert opinion, analysis, and advice within dispute values of up to £700 million. 

Matt Riding (B.Sc., M.Sc., M.Sc., Ph.D.), Senior Engineer 
Matt Riding has seven years of experience in ground risk and remediation. His academic research focused on the fate and transport of new and emerging chemicals within the environment, as well as developing methods to profile their mechanisms of toxicity in prokaryotic and eukaryotic cells.