As concerns over PFAS contamination escalate across the UK and beyond, industry stakeholders are grappling with a pressing question: Are current regulatory guidelines doing enough to protect public health and the environment? From municipal water authorities and regulatory agencies to academic scientists and filtration technology developers, opinions diverge sharply. While some experts defend the status quo as a necessary first step, others argue for a much more stringent overhaul of regulations to reflect current scientific understanding. So, who’s right—and what’s at stake?
The growing complexity of PFAS regulation
Per- and polyfluoroalkyl substances (PFAS), often called “forever chemicals,” are increasingly under the microscope. These synthetic compounds, found in everything from firefighting foam to non-stick cookware, are remarkably resistant to degradation in the environment and human body. More than 4,700 PFAS variants have been identified, yet only a handful are currently regulated.
The UK currently does not impose legally binding maximum contaminant levels (MCLs) for PFAS in drinking water. Instead, it relies on guideline values such as those set by the Drinking Water Inspectorate (DWI), which recommends a threshold of 100 ng/L for the sum of 20 PFAS. This is in sharp contrast to the United States, where the EPA recently proposed enforceable MCLs as low as 4 ng/L for PFOA and PFOS individually.
Many experts argue that this discrepancy illustrates how outdated or overly permissive UK recommendations may be. According to Dr. Louise Campbell, toxicologist at the University of Manchester, “We now know that PFAS bioaccumulate at lower levels than previously thought. Recommendations that don’t reflect this are inherently insufficient.”
Industry insiders speak out
Water utility companies find themselves at the frontlines of this debate, having to navigate both public concern and evolving guidelines. Richard McDarley, lead water quality manager at Thames Hydrologics, stresses the operational challenges:
“Most current PFAS guidelines are non-binding in the UK, which creates uncertainty. We invest heavily in filtration infrastructure, but without clear legal mandates, it’s difficult to justify long-term planning and budgeting.”
For companies like Thames Hydrologics, questions about liability and public trust loom large. Public campaigns and investigative journalism—including the BBC’s recent coverage of “forever chemical” levels in English rivers—are putting pressure on stakeholders to act more decisively. Meanwhile, water companies feel they are sometimes unfairly blamed for PFAS instances originating upstream, such as from industrial discharges or agricultural runoff.
Scientific evidence demands a rethink
Recent scientific research suggests that PFAS exposure—even at extremely low concentrations—may have adverse health effects, including compromised immune response, hormonal disruption, and increased risk of certain cancers. A 2023 meta-analysis published in Environmental Health Perspectives revealed epidemiological links between PFAS and decreased vaccine effectiveness in children.
“The cumulative effect of multiple PFAS compounds, even those not yet studied in depth, must be considered,” says Professor Elena Zhao, who leads the Centre for Environmental Toxicology at the University of Edinburgh. “The current piecemeal approach—monitoring just a few compounds—undermines comprehensive risk assessments.”
This consensus is gaining traction among academic and health bodies. The European Chemicals Agency (ECHA) has proposed classifying PFAS as a group, rather than regulating each individually. The rationale? Chemical genera like PFAS share properties and risks, requiring a broader and more preventive regulatory stance.
The filtration technology gap
Another contentious point in PFAS guideline debates is the stringency of standards relative to available water purification technologies. Critics of tighter regulation often argue that current filtration methods, such as granular activated carbon (GAC) and reverse osmosis (RO), are not economically feasible at scale.
However, innovations in PFAS removal are rapidly emerging. UK-based firm Aquasafe Systems recently piloted a hybrid ion-exchange/RO system capable of reducing PFAS below 1 ng/L in lab trials. The company’s CEO, Fiona Reid, believes it’s time regulators raise the bar:
“There’s a misconception that we don’t have the tech to meet lower contamination thresholds. The truth is, we do—we just need policy direction and public investment to bring it to scale.”
Global lessons: Looking across borders
International case studies offer valuable context for the UK debate. Nordic nations, for example, have been early adopters of stricter PFAS policies. Norway banned certain PFAS in consumer products as early as 2014. Denmark went further by establishing a national screening program to monitor PFAS in groundwater sources.
Meanwhile, the US Environmental Protection Agency has taken a bolder stance in 2024, adopting legally enforceable limits for PFAS in drinking water. This move has faced pushback from industry groups but earned praise from environmental activists and public health advocates alike.
Kate Turner, policy advisor to the European Water Federation, sees these international shifts as proof of momentum: “The UK risks falling behind. Harmonised, evidence-based guidelines would protect both consumers and water providers from long-term legal and health liabilities.”
The challenge of cumulative exposure
Current guidelines largely fail to account for cumulative PFAS exposure. A person may ingest PFAS not just through tap water, but also via food packaging, household dust, cosmetics, and more. These exposures interact cumulatively in the human body, which PFAS persist in for years, even decades.
That’s why experts are now calling for a total exposure framework—one that considers aggregate intake across all sources. The European Food Safety Authority (EFSA) has already adopted such an approach in its tolerable weekly intake (TWI) guidelines. Currently, the UK lacks an equivalent measure.
“It’s like trying to bail water from a boat while ignoring the leak,” says Dr. Zac Willis, a chemist specialising in environmental bioaccumulation. “Unless we look at the total picture, we risk underestimating the real threat these chemicals pose.”
What could meaningful updates look like?
So, how could guidelines evolve to better reflect today’s challenges? Experts suggest several concrete steps:
- Legally binding MCLs: Move beyond recommendations to enforceable national standards, starting with the most hazardous PFAS such as PFOA and PFOS.
- Group-based regulation: Treat PFAS as a chemical family when assessing risk, rather than regulating compounds on an individual basis.
- Transparency requirements: Mandate contaminant disclosure by water utilities and relevant industries, with searchable data sets available to the public.
- Public testing initiatives: Encourage cost-sharing schemes that subsidise testing and filtration for at-risk communities.
- Research and investment: Fund large-scale studies on cumulative exposure and support the deployment of advanced filtration technologies nationwide.
Navigating uncertainty through precaution
As debates continue, the key lies in adopting the precautionary principle—acting in the face of scientific uncertainty to mitigate potential harm. While not all PFAS exposure thresholds are definitively proven to produce long-term health effects, the body of evidence is mounting rapidly. Failure to act preemptively risks public health and intensifies future remediation costs.
For experts like Fiona Reid and Professor Zhao, the issue is no longer one of feasibility, but of political will. With reliable science, promising technologies, and growing public awareness, lifting the fog around PFAS regulation may begin with the simplest step of all—listening to those on the frontline and prioritising preventative action over reactive policy.
In the end, the debate about PFAS guidelines isn’t merely academic. It touches every glass of water, every farming field, and every community sitting downstream of industrial spillover. With so much at stake, the margin for caution is thin—and the imperative for change compelling.