A PFAS exclusion on a client's current policy tells only part of the story. As blood tests arranged by law firm Leigh Day find elevated PFOA levels in most of the residents tested near a Lancashire chemical plant, the exposure that matters may sit in policies written decades ago.
Polly Sayers, associate (registered foreign lawyer) and insurance market analyst at HCR Legal LLP, said many PFAS claims are framed around progressive exposure over years or decades rather than a single period, which can bring older policies into play alongside current ones.
"It's not enough for the insurer of the current policy to just look at their wording and perhaps have a PFAS exclusion in there and say, great, we're safe," Sayers said. "They will have to interrogate their current wording alongside any previous iterations from any decades past."
Commercial general liability, employers' liability, D&O, pollution and professional liability cover could all be triggered. Where several insurers covered successive operators, liability may be split according to time on risk or exposure. The outcome would depend on the wordings in force, which operators were active when, and how the contamination spread.
Asbestos showed that when primary defendants exit the market, claimants look for a solvent defendant, which can push liability onto suppliers, distributors and other peripheral parties. Such companies have already faced PFAS claims in the US, although she cautioned that the US is not an easy comparison.
Under Part 2A of the Environmental Protection Act 1990, anyone who caused or knowingly permitted contamination can be required to clean it up. No formal determination has yet been made at the sites now under investigation. Sayers said a determination would trigger clean-up obligations, strengthen claimants' evidence and prompt notifications under CGL, pollution and environmental impairment liability (EIL) policies, putting any PFAS exclusion wording under heavy scrutiny.
A claim brought on behalf of a household in Bentham, North Yorkshire, against firefighting foam maker Angus Fire settled in 2025 with no admission of liability. Sayers said it had been expected to become an early test case, and she expects a similar claim to be brought before long.
Sayers said the market is right to draw parallels with other long-tail liabilities. Talc, like PFAS, involved alleged exposure over decades of consumer use and a large claimant group. The key difference from asbestos, she said, is causation: asbestos ultimately produced established signature diseases, and PFAS has not.
"We don't have that science. That science isn't settled yet," she said.
Personal injury claimants face substantial hurdles on limitation and the "but-for" test, but she warned brokers against assuming the science will not evolve. Defence costs, she added, would be substantial regardless of the outcome.
Sayers said some group actions are already being framed around property value, nuisance and loss of amenity, none of which requires proof of illness. In Australia, a class action over firefighting foam contamination around Defence sites settled for A$132.7m in 2023. It covered about 30,000 group members, and the Commonwealth admitted no liability.
"Don't assume that no illness means no claim," she said.
Exposure extends beyond manufacturing and chemicals clients to owners of commercial and residential property, and to agricultural businesses whose soil, water, produce or livestock could be affected.
Sayers cited a 2024 report prepared by Jacobs for the Environment Agency, which estimated between 2,900 and 10,200 high-risk PFAS sites in England. Those include airports, military bases, fire stations, landfills and wastewater treatment works. Separate research from Brunel University of London, using the Environment Agency's 2024 monitoring data, detected at least one PFAS compound in 92% of England's monitored surface waterbodies.
"The concern at the moment is the sites that we're hearing about now are the tip of the iceberg," Sayers said. She expects more to surface as the government and claimant groups step up investigations.
For clients with any PFAS history, her advice is to audit exposure going back decades rather than rely on current wordings. She warned against expecting a pollution exclusion to carry the policy, since PFAS exclusions vary widely in scope and some broadly drafted versions could face heavy scrutiny.
Dedicated EIL or pollution legal liability cover may offer broader protection for gradual contamination and clean-up costs, she said. Some environmental insurers, however, have begun excluding PFAS themselves. A client that no longer uses PFAS still needs its historic policies reviewed, she said, because contamination that does not degrade can continue to surface.
Sayers said the government's monitoring programmes are expected to publish preliminary results in late 2026 or early 2027. As that data lands, the map of UK contamination could grow, and so could the number of legacy policies that may have to answer for it.
