England’s planned law on ‘forever chemicals’ in tap water should cover the 48 that water companies already test for.
Pfas are a large family of man-made chemicals that are commonly used to make products non-stick, waterproof or grease-proof, including products such as frying pans, outdoor clothing, food packaging and firefighting foam. Sounds beneficial: so, what is the issue? They break down very, very slowly. Some will even stay in the environment for hundreds and hundreds of years, which is why people call them ‘forever chemicals’, as they can accumulate in the environment and in human bodies over time. As some people may be aware, PFAS have also been linked to health problems, including kidney/testicular cancers and thyroid disease, although the UK government says the evidence on many of them is still being studied.
Establishing a legal limit
In February 2026, the UK government published its first national PFAS Plan, which promises a public consultation during 2026 on a legal limit for PFAS in tap water across England.
England currently has official guidance on PFAS that water companies are told to follow, with, however, no limit written into law. The government says a legal limit would make it easier for the Drinking Water Inspectorate (the body that checks tap water in England and Wales) to take action against a water company that goes over it. The consultation will also have to decide which PFAS chemicals count toward the new limit, because there are thousands of them. The government’s own plan says it is not practical to examine every one individually. Most sets of rules therefore name a list of chemicals, add up how much of those listed chemicals is in the water, and check the total against a limit.
Scotland, England and Wales all use the same limit of 0.1 micrograms per litre, which works out at one ten-millionth of a gram of PFAS in a litre of water, but each counts a different list of chemicals toward it. Since January 2023, Scottish law has limited the combined amount of 20 named PFAS, the same 20 the European Union uses. In England and Wales, official guidance applies the limit to the combined amount of 48 named PFAS, and a water company that reaches it must report it and also act to bring levels down. Northern Ireland has no PFAS limit in its drinking water rules, although NI Water has tested for PFAS every year since 2020 and says its treated water has stayed within the EU limits (Fig. 1).
Advantages of granting legal force to England’s extended list
A policy adviser at the Royal Society of Chemistry wrote that England’s 48-chemical total goes further than the limits in the EU and Scotland. She also warned that guidance telling companies what they are “expected to” do gives families less certainty than a law. England’s new law can give it both the longer list and the legal force.
Scottish Water tested untreated water from 316 sites for the 20 chemicals in Scotland’s legal limit, and researchers at the University of Dundee analysed the results for Scotland’s Centre of Expertise for Waters. The most common was found in almost half of the samples. The amounts were indeed small: in all but 16 samples, the combined total came to a tenth of the legal limit or less, and Scotland’s drinking water regulator reported no breaches of the limit in 2024. The Dundee researchers explained that all 20 chemicals on Scotland’s list belong to one group of PFAS, the end products that many other PFAS eventually break down into. After some older PFAS were banned, manufacturers switched to replacement PFAS, and many of these move more easily through soil and water and are being found more often in rivers and drinking water. The researchers warned that testing for a fixed list can miss a significant part of the PFAS in a sample, and they recommended that Scotland look at testing for more of the newer replacement chemicals.
England’s list of 48 already includes some of these newer replacement chemicals. One of them, a chemical used in firefighting foam, was added to England’s list.
The balance between safety and EU alignment
The risk for England’s new law comes from the government’s wish to keep UK chemical rules close to those of the European Union. In July 2026, replying to MPs on the Environmental Audit Committee, ministers said they want closer alignment with the EU to “reduce unnecessary friction”. Matching EU rules helps businesses that sell products such as clothing or cookware in both markets. English water companies supply homes and businesses in England, so copying the EU’s list of 20 would cut the number of chemicals England can enforce from 48 to 20 without making trade any easier. The EU itself sets two tap water limits: the one on its list of 20, and a second, higher limit on all PFAS added together.
The government’s consultation should propose a legal limit of 0.1 micrograms per litre on the combined total of all 48 chemicals England already checks, with a clear process for adding new chemicals as evidence comes in.
Wales uses the same guidance as England but falls outside the planned consultation, which covers England alone, so the Welsh Government would need its own law to give Welsh households the same protection. Scotland’s regulator already asks Scottish Water to test for 29 more PFAS beyond the 20 in the law. Northern Ireland has annual NI Water test results going back to 2020, collected to prepare for rules matching the EU’s, and can use them to set its first limit.
Water companies in England already test for 48 of these chemicals, and the government says none of their supplies goes over the limit, so writing the 48 into law asks them to keep doing today’s work under a rule the inspectorate can enforce.
