Measuring PFAS: matching what's in the environment with what's commercially available

Dr David Megson and Geraint Williams explain why we’re finding a mismatch with PFAS contamination and testing in our laboratories.

PFAS (per- and polyfluoroalkyl substances) have emerged as one of the most complex and persistent challenges in environmental monitoring.

Dubbed “forever chemicals” due to their resistance to degradation, PFAS are now known to be widespread in air and water. With links to a range of human health and environmental risks.

Yet as regulatory scrutiny intensifies, a critical problem remains. The gap between the PFAS compounds found in the environment and what laboratories can reliably detect.

In a recent expert-led webinar on the Envirotech website, Dr David Megson, reader in chemistry and environmental forensics at Manchester Metropolitan University, and Geraint Williams, associate technical director at HKA, unpacked the core issues driving this mismatch. As well as covering what needs to change.

Understanding the PFAS landscape

“PFAS is not one chemical,” David began.

“It’s a whole family - over 7 million potential substances.”

Despite this, most laboratories are only equipped to test for around 20 to 50 individual compounds.

That means a vast portion of PFAS pollution remains undetected and unreported.

This detection gap stems not just from analytical limitations, but also from regulatory lag.

As Geraint Williams highlighted: “When we talk about PFAS risk, we’re often doing so with incomplete information.”

Sampling methods and instrument sensitivity all contribute to a monitoring landscape that underrepresents real-world contamination.

The problem with proxy testing

Much of today’s PFAS testing focuses on a small subset of substances. Typically perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS). As well as a handful of others.

These chemicals are used as proxies, assumed to represent the broader PFAS family. 

But as the speakers pointed out, this assumption can be dangerously misleading.

“Relying on a few analytes to stand in for thousands is like trying to understand a conversation by hearing only every tenth word,” David pointed out.

Many PFAS compounds don’t behave like their better-known counterparts.

This means risk assessments and remediation strategies may be flawed from the outset.

Geraint added: “It’s becoming increasingly clear that the scope of testing needs to evolve.

“As regulatory standards expand, so must our ability to track and quantify what’s actually present.”

Sampling challenges and the hidden burden

Beyond analytical capability, sampling plays a pivotal role in shaping results.

If samples are not properly preserved or taken at the right locations, even the most advanced labs can’t deliver meaningful data.

Geraint emphasised the importance of understanding local conditions and industrial histories when designing sampling campaigns.

“You have to know what you’re looking for and where to look. Otherwise, you risk missing contamination hotspots.”

Moreover, total PFAS concentrations can sometimes be inferred using sum parameters such as total oxidisable precursor assay (TOPA) or extractable organic fluorine (EOF). 

While these methods offer broader insight, they come with their own limitations and standardisation issues.

The role of high-resolution mass spectrometry

One promising avenue for overcoming PFAS blind spots is high-resolution mass spectrometry (HRMS).

These instruments can detect a much wider range of compounds, including previously unmonitored PFAS.

David discussed ongoing research that uses HRMS to detect unknown or emerging PFAS at contaminated sites.

“We’re finding compounds that aren’t even on regulatory lists yet,” he noted.

“This shows just how far behind the legislation can be.”

However, the downside is complexity.

HRMS generates enormous volumes of data, which require skilled interpretation.

It also demands substantial financial investment. Meaning adoption remains limited to academic and high-end commercial labs.

What needs to change?

The webinar made it clear that PFAS monitoring needs a multi-pronged approach. Better data, better guidance and broader collaboration.

“Testing is only one part of the puzzle,” said Geraint.

“We also need improved regulatory alignment, more funding for research and education for both clients and regulators about what PFAS data really mean.”

David echoed this sentiment, calling for standardisation of PFAS methodologies and greater transparency around detection limits and performance criteria.

“We need to move towards fit-for-purpose testing rather than just ticking regulatory boxes,” he said.

Building flexible monitoring systems

A recurring theme of the discussion was adaptability.

With PFAS regulations changing rapidly across the world, monitoring systems must be flexible enough to evolve.

The speakers urged stakeholders to avoid narrow, checklist-style approaches. Instead invest in systems that can accommodate new analytical targets and sampling protocols.

“Designing systems that can adapt to new standards is essential,” Geraint explained. 

“Otherwise, we’ll be chasing regulations rather than shaping them.”

Industry engagement and responsibility

The experts also stressed the need for responsible action within industry.

Often, PFAS data is collected in response to legal or reputational pressure.

But proactive monitoring can prevent damage before it occurs.

Geraint cited examples from the construction and brownfield redevelopment sectors. 

Here, early engagement with PFAS monitoring has helped reduce cleanup costs and avoid regulatory delays.

“This is not just a regulatory issue,” he said.

“It’s a reputational and operational one.”

The role of litigation

Given the growing number of PFAS-related lawsuits, accurate and defensible monitoring is becoming even more critical.

David, who regularly works on PFAS litigation in North America, shared how poor sampling or incomplete testing can significantly undermine legal cases.

“You don’t want to be in court explaining why your dataset missed half the contamination,” he said.

In high-stakes litigation, the quality of environmental data can determine liability or potential penalties.

That’s why robust, transparent methodologies are essential from day one.

Looking ahead

As both science and regulation evolve, the monitoring community must stay agile.

PFAS contamination is no longer a fringe issue. It is now a central challenge for environmental protection.

This webinar underscored the importance of bridging the divide between environmental presence and analytical capability.

David and Geraint Williams made a compelling case for reform: expanding testing scope, investing in better sampling, embracing high-resolution technologies and future-proofing monitoring systems.

While the road ahead may be complex, improved PFAS monitoring is not only possible - it is essential.

To watch the webinar in full, visit https://ilmt.co/TL/NnEl.