Litigating “Forever Chemicals”

19 July, 2023

This blog is the first of a two-part series on PFAS, or so-called “forever chemicals”. Part 1 provides an overview of the environmental and public health risks associated with PFAS and explores the potential legal avenues for providing redress in the courts. Part 2 will consider in more detail the regulatory regime governing the use of PFAS in the EU and UK.

Litigating “Forever Chemicals”

This blog is the first of a two-part series on PFAS, or so-called “forever chemicals”. Part 1 provides an overview of the environmental and public health risks associated with PFAS and explores the potential legal avenues for providing redress in the courts. Part 2 will consider in more detail the regulatory regime governing the use of PFAS in the EU and UK.

What are PFAS and where can they be found?

Per- and poly-fluoroalkyl substances (PFAS), a family of approximately 10,000 chemicals, are notoriously difficult to break down, hence the colloquial term, “forever chemicals”. However, not only are they “forever”, they are also ubiquitous. PFAS are used in non-stick cookware and stain-resistant surfaces; dental floss; menstrual products; food packaging; takeaway containers; plastic lunch boxes; waterproof and synthetic clothing; cosmetics and firefighting foam, to name but a few ways in which most people will come into contact with these chemicals on a daily basis.

It might come as no surprise from this brief illustration of the omnipresence of PFAS that they have been widely detected in water, soil, air and food, as well as the most isolated corners of the planet. A recent Oxford University-led study found that Norwegian Arctic ice is contaminated with high levels of PFAS that may constitute an environmental stressor for the region’s wildlife. The study also found that when this ice melts (as is happening at an accelerated rate due to the climate crisis), chemicals move downstream from the glaciers, polluting the Arctic fjords and tundra. PFAS have been detected in the Mariana Trench in the Pacific Ocean which, at approximately 10km deep, is the most remote and inaccessible place on the planet. Closer to home, a recent mapping study found PFAS at approximately 17,000 sites across the UK and Europe. 

Environmental and public health risks

As well as the most far-flung corners of the planet, PFAS have found their way into the bloodstreams of humans and animals. They attach to the proteins in our blood and accumulate within us as we age. Peer-reviewed medical research demonstrates the significant risk to public health posed by these chemicals, linking PFAS to multiple cancers, ulcerative colitis, immunotoxicity, endocrine disorders, pregnancy-induced hypertension, decreased fertility and infertility, high cholesterol and thyroid disease. 

Although the sheer scale of PFAS’ presence in our everyday lives means that it is inevitable that most, if not all, humans have been and are exposed to these chemicals on a regular basis, those most at risk are people working in occupations such as firefighting or chemicals manufacturing and processing, or who live near contaminated soil and water sources. For example, such is the scale of the PFAS pollution in groundwater near a PFAS manufacturing site in Zwijndrecht, Flanders, that people living within a 10-mile radius of the site have been told not to eat any eggs laid in their gardens and avoid homegrown vegetables.

The position in the UK

In the UK, the highest levels of PFAS were found in discharges from a chemicals plant run by AGC Chemicals Europe on the River Wyre. 

Discharges from AGC Chemicals Europe in Thornton-Cleveleys into the River Wyre were recently evaluated by the Environment Agency which detected high levels of PFAS. Based on monitoring data, the Environment Agency estimated that an average of 783kg of EEA-NH4 (a PFAS classified as “very persistent”, “mobile” and “reprotoxic category 2”), is discharged by AGC into the river each year. Samples of fish in the Wyre taken by Defra’s Centre for Environment, Fisheries and Aquaculture Science, have also shown high levels of PFAS, with flounder containing up to 11,000ng/kg.

AGC is by no means solely responsible for PFAS pollution in the UK’s watercourses. Such is the scale of PFAS pollution in this country that, according to data obtained from water companies and the Environment Agency, approximately 120 samples of drinking water sources have been found to contain concentrations of PFAS above the Drinking Water Inspectorate’s (DWI) recommended maximum level of 100ng/l. This is in a context where, as per the figures released by the Environment Agency in 2020, for the first time, no river in England had achieved good chemical status.

It will be apparent from the above that it is almost impossible to avoid contact with PFAS. As scientists increasingly link PFAS contamination with a variety of serious illnesses and environmental contamination, it will be necessary to reevaluate our relationship with these substances and consider the concrete steps (legal and otherwise) that can be taken to reduce their presence and risk and achieve accountability for harms already suffered. 

Legal challenges and opportunities

Legal hurdles

The example of discharges from a chemicals manufacturing company into a river is an interesting case study on the complexities of bringing a successful legal challenge to the use and discharge of PFAS on public health and environmental contamination grounds. 

It is important to note at the outset that many industrial discharges into rivers are prima facie legal, i.e. their discharge is allowed under a relevant permit. For example, AGC Chemicals is permitted to discharge effluent into the River Wyre pursuant to the permit issued to it by the Environment Agency under the Environmental Permitting (England & Wales) Regulations 2016. However, even if such industrial discharges are prima facie legal under their permits, the question posed by this blog is whether those discharges might still be vulnerable to legal challenge  due to the risks to human and environmental health posed by the volumes of PFAS contained within them.

Prospective litigants seeking to challenge, through a claim in statutory nuisance for example, the use and discharge of PFAS on environmental and public health grounds, face the inherent difficulty of establishing legal causation for alleged harms. Of the approximately 10,000 chemicals classed as PFAS, only perfluorooctane sulfonic acid (PFOS) and perfluorooctane carboxylic acid (PFOA) are globally regulated (including in the UK) due to their documented harmful effects. Although the peer-reviewed scientific studies cited above point to the wide-ranging harmful effects on public and environmental health of many other varieties of PFAS, the science is still evolving on their individual and cumulative impacts. This might pose difficulties for a person or group of people seeking to draw a direct causal link between their ill-health and a discharge or series of discharges from a chemicals company or PFAS-reliant industry.

Difficulties in establishing legal causation are further evidenced by the fact that it is not straightforward to definitively trace the presence of PFAS in soil, rivers and other watercourses to a specific discharge by a specific company. The situation becomes even more complex when one factors in the lingering presence in soil and water sources of PFAS that are now regulated but, true to the name “forever chemicals”, result from historical usage whose chemicals have not yet broken down and will not for thousands of years. 

By way of illustration, AGC Chemicals’ response to the fact that 700 types of PFAS (including the regulated PFOA) were detected in effluent coming from its site was that any PFOA must have resulted from historical usage because it no longer uses PFOA in its manufacturing process. If this were accepted, it still leaves open the question of where the other 699 types of PFAS came from and the harm they might pose to environmental and human health. This is particularly so in the light of the Environment Agency’s detection of what it describes as the “very persistent”, “mobile” and “reprotoxic category 2” PFAS, EEA-NH4, in AGC Chemicals’ discharges.

Successful US litigation 

Despite these difficulties, prospective litigants could learn from the successful challenges brought against chemicals companies in the US. These claims will be familiar to readers who have seen Dark Waters, the 2019 legal thriller depicting the true story of US corporate defence lawyer Robert Bilott’s long-running series of legal challenges against the chemical manufacturing company DuPont after it contaminated a town with PFAS used for the production of Teflon non-stick cookware.

The first hurdle that Bilott and his clients had to overcome was arguing that 70,000 people had been poisoned through exposure to PFOA. The difficulty being, at that time, PFOA was not yet recognised by the government as a toxin and there was scant information available about its public health impacts. In response, Bilott brought a class-action suit in West Virginia in 2011. West Virginia was a strategic choice as it had become one of the first states to recognise a medical-monitoring claim. In this type of claim, a plaintiff need only prove that they had been exposed to a toxin and if they subsequently won, the defendant would be required to fund regular medical tests. If a plaintiff later became ill, they could then sue retroactively for damages. 

As the class-action suit progressed, the Environment Protection Agency (“the EPA”), began its own investigation into the toxicity of PFOA. Its initial findings indicated that PFOA might pose human health risks not only to those drinking tainted water, but also to anyone cooking with Teflon pans. This scientific evidence led DuPont to settle the class-action suit in September 2004. As part of the settlement, DuPont agreed to fund a scientific study to determine whether there was a ‘‘probable link’’ between PFOA and any diseases. If such links were shown to exist, it committed itself to funding medical monitoring of the affected group in perpetuity. Until the conclusion of this scientific study, class members were forbidden from filing personal-injury claims. 

Seven years later, scientists began to release their findings that there was indeed a “probable link” between PFOA, several types of cancer and other diseases, thereby opening the door to thousands of successful personal injury claims against DuPont. To give but one example, in January 2021, DuPont, Corteva, and Chemours announced an agreement to resolve dozens of personal injury cases pending in Ohio for $83 million. These cases are in addition to the approximately 3500 personal injury cases that were settled in Ohio in 2017 for $670.1 million. DuPont’s woes are far from over as it and two related companies confirmed in June 2023 that they would pay close to $1.2bn to settle liability claims for the PFAS cleanup costs of public drinking water utility companies serving the vast majority of the US population.

The potential for claims in statutory nuisance for UK PFAS litigation

Turning back to the UK, there are many lessons to be drawn from the long running saga of DuPont cases. As alluded to earlier in this post and as will be apparent from the above analysis of the DuPont cases, one of the main hurdles facing potential claimants is the need to produce evidence of a causative link between PFAS and risks to environmental and public health. However, the growing body of scientific evidence, Environment Agency investigations into specific discharges and a recent report by the UK Health Service Executive presented as “the most comprehensive British analysis of these chemicals ever”, suggest that the time might be increasingly ripe in the UK for claims such as those brought against DuPont in the US.

A clear lesson from the US is that such actions have the potential to give rise to very significant financial liability for those found responsible.

One potential avenue available to prospective litigants concerned about the risks posed by the use and discharge of forever chemicals in the UK is a claim in statutory nuisance under s.79(1) of the Environmental Protection Act 1990 (“the EPA 1990”). As stated by McCracken, Jones and Pereira on Statutory Nuisance (Fourth Edition, 2019) at page 1, “statutory nuisance legislation is designed to provide a summary procedure for the remedy of a disparate collection of unacceptable states of affairs, most of which put at risk human health or harm the amenity of neighbours.” 

There are nine categories of statutory nuisance under s.79(1) of the EPA 1990. They relate to: (a) the state of premises; (b) smoke emissions; (c) fumes or gases from dwellings; (d) effluvia from industrial, trade or business premises; (e) accumulations or deposits; (f) animals; (fa) insects; (fb) light; (g) noise from premises; (ga) noise from vehicles or equipment in a street; (h) other matters declared by other Acts to be statutory nuisances. All of these categories have two limbs: they require the existence of something either “prejudicial to health” or “a nuisance.” 

It is the first limb, “prejudicial to health” that is of interest to us. It is defined by s.79(7) of the EPA 1990 as “injurious or likely to cause injury to health” (emphasis added). McCracken, Jones and Pereira highlight at page 2 that opinions will plainly differ about what is likely to cause injury to health but recall that judges have suggested it is broad enough to apply to that which interferes with “the vigour and vitality of the well” (Malton Board of Health v Malton Manure Co (1879) 4 Ex D 302). 

A person whose health is or is likely to be injured by a statutory nuisance (an “aggrieved person”) is entitled to bring proceedings directly in the magistrates’ court against the person responsible for the statutory nuisance under s.82 of the EPA 1990. A person in the UK whose health was injured or likely to be injured by a discharge containing PFAS could potentially bring a claim in statutory nuisance under s.82 against the company responsible for causing the statutory nuisance.

There are no express statutory defences to proceedings brought under s.82. Importantly for prospective defendants, this means that there is no express provision under s.82 for a best practicable means defence (McCracken, Jones & Pereira, page 223). However, taking the example of a company facing a claim in statutory nuisance for discharging effluent containing PFAS, the defendant company could argue that the complainant is not a “person aggrieved” (no direct link between the discharge and injury or risk of injury to their health) or that it is not responsible for the nuisance (certain toxic PFAS remain in the soil or water from historical usage). It is unlikely that the mere existence of a permit would provide a defence because although a discharge may be prima facie lawful, a permit does not allow someone undertaking the activities contained within it to cause a statutory nuisance when doing so.


In the light of the increasingly documented public health risks associated with PFAS, it is this author’s view that we won’t have long to wait before the issue of “forever chemicals” appears before the UK courts. Based on the legal test for bringing claims where an issue falls within one of the categories of s.79(1) of the EPA 1990 and is “injurious or likely to cause injury to health”, a claim in statutory nuisance could present a valid legal avenue for those seeking redress and remedy in respect of the environmental and public health risks associated with the use and discharge of forever chemicals in the UK. However, as discussed throughout this blog and with particular reference to the US DuPont litigation, courts will require expert evidence by those with relevant professional experience. This need not be limited to the medical profession but can encompass the expertise of environmental health officers and other experts recognised by the courts.

Claire Nevin is a pupil barrister at Francis Taylor Building.

This article was amended on 30 August 2023 for reasons of accuracy, to remove a reference to fines issued for chemical spillage on the river Wyre.

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