Getting to grips with the PFAS problem

There’s plenty we don’t know about PFAS: including the full extent of their adverse health and environmental effects, as well as how we’re going to clean them up. But with regulatory, scientific and public scrutiny all increasing, we’re getting to grips with the problem for the first time.

Ubiquity, toxicity

Dubbed ‘forever chemicals’ because their enormously strong carbon-fluorine bonds can resist degradation indefinitely, PFAS have become so ubiquitous as to be detected in the liver of an Arctic polar bear and in the blood of almost 99% of Americans. In the US, researchers requiring blood samples uncontaminated with PFAS reportedly had to resort to 10 vials taken from soldiers between 1948 and 1951.

The chemicals’ non-stick, grease- and water repellent properties have made them extremely useful in a huge range of manufacturing applications from the 1940s to the present day – including including non-stick pans, food packaging materials, paints, carpets, cleaning products, and firefighting foams. Yet the same characteristics also make them extremely mobile – able to ‘slide’ away from their original products in locations like landfills, and into the wider environment. Then, because they are absorbed more quickly than they can be excreted, PFAS bioaccumulate in water, plants, wildlife, and humans - bringing with them severe health consequences.

The World Health Organisation’s International Agency for Research on Cancer (IARC) recently published detailed evaluations showing that the PFAS substances perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were ‘carcinogenic to humans’ and ‘possibly carcinogenic’ respectively. The former director of the US National Institute for Environmental Health Sciences, Linda Birnbaum, adds that “there are now hundreds of epidemiology studies showing (PFAS’) associations with a wide variety of (health) effects, including cancer, liver effects, kidney effects, effects on development and reproduction. .... neurodevelopment, (and) type 2 diabetes. “The more you look, the more you begin to find associations with this very broad class of chemicals,” she says.

Thousands of PFAS, ‘decades of cleanup’

Another major difficulty with PFAS is that there are so many of them – the vast majority of which we know little about.

LGC’s Dr Dan Biggerstaff, a chemist who played a key role in developing the revolutionary PFASiMix multi-analyte testing kit, points out that there is “no toxicological data” on thousands of PFAS in use and in the environment, and therefore “no meaningful regulation to deal with these compounds as a broad class.”

Dr David Megson, a senior lecturer in chemistry and environmental forensics at Manchester Metropolitan University, agrees - saying testing and regulation are being left behind because the number of PFAS products in use and in the environment is growing so fast. “People are doing more routine monitoring, but the number of PFAS we need to be worried about has gone from two, to 17, to 47 and now we could have 14,000,” he says. “By the time a two-year monitoring programme has been performed, it’s almost obsolete.”

The scientific consensus also seems to be that “a long, bumpy road remains” before we can make significant progress on cleaning up PFAS chemicals already in our environment. For example, the high temperature incineration process that the US Department of Defense is considering as a means of disposing of its two million gallons of stockpiled firefighting foam may be both ineffective and unsafeA number of other potential methods for separating, concentrating and destroying PFAS are currently under investigation – including nanofiltration, advanced coagulation, supercritical water oxidation (SCWO) and sonolysis – but the remediation process is likely to be complex, expensive and long-term.

“It's multiple decades of cleanup,” predicts Kobe Nagar, the chairman of SCWO technology company 374Water.

“Unfortunately, we as a society are still manufacturing and selling (PFAS) into the market. So I think the first thing we need to do is stop putting it in our ecosystem.”

More concern, more regulation

If there’s a silver lining to the giant cloud that is PFAS pollution, it’s the huge amount of scientific reports, news stories, and environmental initiatives that it generates. As the US Environmental Protection Agency (EPA) puts it, “(this) growing number of published reports of PFAS exposures is leading to a growing level of interest and concern by states, tribes, and other localities.”

Over the last year, researchers have published papers about the presence of PFAS in unexpected places such as toilet paper, ‘eco-friendly’ drinking straws, and laboratory materials. The Dutch government warned its citizens against swallowing sea foam because of PFAS, and both the State of Maine and the US Congress announced proposals to outlaw PFAS in food packaging.

In America, the Biden administration’s promise of a ‘laser focus’ on PFAS has led to the EPA introducing new legal drinking water limits for six of the most studied PFAS compounds, and slashing the limit for PFOS and PFOA in drinking water from 70 ppt to 4 ppt. In December 2021, the EPA also signed into law its Unregulated Contaminant Monitoring Rule (UCMR5), which ordered the monitoring of 29 PFAS substances in drinking water. Furthermore, China is considering a blanket ban on the import, export and production of PFOS and PFHxS, as well a near-total prohibition of PFOA.

Significantly, this increased regulation across the world has already prompted one leading manufacturer to withdraw from the PFAS sector. The US multinational company 3M, whose net PFAS sales are worth around $1.3 billion each year, announced that it would: “Exit all PFAS manufacturing” and “Work to discontinue use of PFAS across our product portfolio” by the end of 2025. It said it had taken the decision after considering “factors such as accelerating regulatory trends focused on reducing or eliminating the presence of PFAS in the environment”.

A game changer from Europe?

But perhaps the single most important development in PFAS regulation last year was a radical plan from five European countries that Chemistry World said “would ban virtually every PFAS currently on the market”. Instead of focusing on individual PFAS substances, the proposal from the Netherlands, Germany, Denmark, Norway, and Sweden attempts to “essentially ban the entire class of more than 10,000 chemicals at a single stroke” – by broadly targeting substances that contain at least one fully fluorinated methyl (CF3–) or methylene (–CF2–) and prohibiting them from being made, used, or sold the EU.

“If the European Commission adopts the proposal, in applications in which these substances are used,” the five countries said – adding that lodging the proposal in itself sent a clear signal to manufacturers that they should rethink their relationships with PFAS.