The Current and Future State of PFAS

They’re pervasive due to the strong carbon-fluorine bonds, making it hard to degrade. However, they are not forever chemicals as they do degrade, just very slowly. This means PFAS can be absorbed into the body, having a negative impact on human health. The future of PFAS is uncertain, with legislation regarding PFAS restrictions in progress but ambiguous.

PFAS has been detected in the blood of a large portion of the global population across all continents – it is prevalent everywhere. There are concerns over the many different potential contamination pathways - through drinking water, ingestion from food packaging, absorption though skin from clothing and cosmetics, and inhalation from airborne contamination. There is research underway to determine whether you can trace the PFAS found in someone’s blood back to the source of contamination.

This raises health concerns due to the toxicological impacts of a handful of PFAS compounds (but not all). PFOA, PFOS, PFNA, PFHxS, and PFDA are proven to have toxicological impacts, with several others assumed to be harmful to human health, but there is a lack of data for others, particularly the newer compounds.

There is a high certainty that PFAS is carcinogenic, with other impacts on human health such as reduced response to vaccines, increased cholesterol levels, thyroid disease, liver damage, delayed mammary gland development, and lower birth weight. There is also a lower certainty of impacts such as obesity, ulcerative colitis, early puberty onset, increased miscarriage risk and low sperm count.

PFAS Legislation

There is very limited legislation in the UK, with many interested parties currently focusing on data collection and monitoring PFAS, rather than determining any concrete restrictions or limitations on the presence of PFAS. There’s lots of consultation about PFAS, with intentions to make a plan but nothing in place yet.

There is an EQS limit in place for PFOS at 0.65 nanograms per litre, but it only applies to freshwater inland surface waters, not ground waters or saline waters. The drinking water inspectorate released a list of 48 different PFAS compounds which has been adopted by the water industry with tiers of action. However, it is still only guidance, and enforcement action can only be taken under the issue of “water not being sufficiently wholesome”, as there is no relevant law in place.

Legislation differs outside of the UK. In the US, there are set federal drinking water standards, with limits for PFOS, PFOA, PFNA, GenX, PFHxS, and PFBS. This then devolves across the country with each state having a different approach towards bans and restrictions on PFAS usage.

In the EU, there aren’t any rigid regulations on PFAS, but there are consultations taking place over a total PFAS ban. This has caused lobbying from many different industries due to the potential impacts on business through economic damages. The main complication is that there is no agreed definition of PFAS, meaning determining legislation can be too vague.

PFAS Remediation Techniques

The current remediation techniques for managing PFAS:

• GAC – often employed for ground water/surface water treatment of PFAS, but contaminated GAC material requires further measures, this works well for longer chain PFAS, typically C8 and above.
• Ion Exchange Resins – can be effective for both shorter and longer chain PFAS, but there are issues with the disposal of the spent resins.
• Reverse Osmosis and Membrane Filtration – can be effective but is highly energy-intensive and therefore expensive.
• Thermal Incineration – often used for disposal of contaminated soils and AFFFs. This is also required to dispose of PFAS-saturated GAC and ion exchange resin.

The main benefit of using PFAS is its inherent resistance to burning. This means that high temperatures exceeding 1000°C are needed to completely break down PFAS, complicating remediation processes.

PFAS Identification Methods

Total Oxidised Precursors (TOP) assay is a method to oxidise the sample to convert undetectable PFAS into shorter chain perfluoroalkyl acids (PFAAs). This is to provide a more accurate picture of the potential PFAS on a site, although the downside is that not all precursor PFAS will oxidise, causing an underestimation of the total potential PFAS.

High Resolution Mass Spectrometry (HR-MS) is a technique using a high-resolution mass spectrometer to identify unknown and untargeted PFAS compounds using accurate mass. However, quantitation is difficult due to a lack of reference standards for many PFAS. Chromatographic techniques are also inherently selective, again resulting in an underestimation of PFAS.

It is also possible to look for fluorine using a combustion ion chromatography system. This is not a great approach for shorter chain PFAS, such as TFA, as they don’t work particularly well with this approach. Also, it can overestimate the total PFAS by potentially including inorganic fluorine.

PFAS is ubiquitous in the environment, and it is clear something must be done to restrict this as it’s proven to have a negative impact on human health. The current legislative approach is uncertain, with no definitive plans in place, but regulations are hopefully expected in the coming years. Please contact us if you have any queries about our PFAS services.