Do we need to worry about PFAS?

PFAS are not always high on the list of potential contaminants considered during site investigations, but should they be? Nancy Tonkin, Technical Director discusses in more detail.

In the UK, Per- and Polyfluroalkyl Substances, (known as PFAS) are not always high on the list of potential contaminants considered during site investigations. Indeed, the general shortage of statutory screening criteria reflect the fact that PFAS have not historically been high priority for regulators either. Toxicology, analysis and remediation of PFAS are still emerging sciences, leading to complexities both in assessing and reducing the risks posed to human health, water resources and the wider environment, and a temptation to avoid the issue, especially where there is a lack of clear, current regulatory drivers.

However, with their widespread use in industry and manufacture, extreme persistence in the environment, and an increasing number of studies suggesting they may be harmful to human health (including as a potential carcinogen), PFAS are attracting growing media, political and regulatory attention around the world. Australia, the United States and parts of Europe are ahead of the UK in terms of regulation, litigation and remediation of PFAS and it seems certain the UK will follow suit with more extensive and tighter regulation and guidance in the near future.

For sites that are, have been, or are close to a source of PFAS contamination, this could leave investors, landowners and developers with large liabilities, costs and delays in the future that they were not aware of at the due diligence or feasibility stage. Future remedial costs associated with operational sites could also be significantly higher than currently anticipated. In addition, in the absence of appropriate reuse criteria, even low levels of PFAS in soils could lead to major challenges with materials management, especially on some large-scale infrastructure projects.


What are PFAS and where are they found?

PFAS are a group of several thousand man-made chemicals, many of which are widely used in industry due to their resistance to water, oil/ grease, fire and heat. They have many applications and have been commonly used in industry and manufacture for their non-stick, stain resistance and lubrication properties and  are also used in electronics, including mobile phone and tablet technology.

As contaminants, PFAS in firefighting foams attracted significant attention following the Buncefield incident and firefighting foams have since been widely identified as a source of contamination in the environment, particularly at airports and military bases. However, there are numerous other sources of PFAS including industrial and manufacturing sites, and many secondary sources such as landfills, wastewater treatment and sewage plants.

PFAS do not biodegrade and, since they have been in use since the 1940s, are widespread in the environment, including  surface water courses and  groundwater. PFAS have been shown to impact drinking water supplies around the world and can also enter the food supply chain through fish bred in contaminated water or crops grown in contaminated soils. The use of treated wastewater for irrigation and PFAS containing biosolids as fertilisers of crops or food for animals grown for human consumption (including dairy) can also increase PFAS concentrations in the food supply. Studies show that human exposure to PFAS is widespread and most people in industrialised countries have measurable amounts of PFAS in their blood.

Legislative Context

European legislation around PFAS is steadily increasing. The compound Perfluorooctane Sulfonate (PFOS), its salts and Perfluorooctane Sulfonyl Fluoride (PFOSF) were listed as Persistent Organic Pollutants (POP) under the Stockholm convention, adopted to EU legislation, in 2009. PFOS is listed as a Water Framework Directive priority hazardous substance in EU directive 2013/39/EU, which also set out Environmental Quality Standards for PFOS in inland surface waters that have been adopted in the UK.

Another PFAS compound, perfluorooctanoic acid (PFOA), was added to the Stockholm convention in 2019. The UK Drinking Water Inspectorate has published guidance values for water companies for both PFOS and PFOA, but UK Drinking Water Standards for these compounds have not yet been issued. 

Perfluorohexane Sulfonate (PFHxS), its salts and related compounds, are currently under review for restriction as POPs under the convention.

A number of European countries, and a number of states in the US and Australia, have gone further in terms of deriving screening/ threshold values for additional PFAS compounds, with the German states of Bavaria and Baden-Württemberg publishing values for nine (a combined value for PFOS, PFOA and PFxS was included) and 13 compounds in groundwater, respectively. However, most of these documents remain provisional. 

The future of PFAS regulation in the UK

Currently the UK is behind a number of EU countries, the US and Australia in the assessment of the risks of PFAS to human health and controlled waters, and in the development of screening criteria. Although currently non-statutory, a greater number of threshold values from around the world are accepted by UK regulators as a measure of PFAS contamination and these - or future UK-derived values - are likely to become embedded into UK regulations in the future. 

However, even around the world, only a fraction of the total number of PFAS compounds have been studied in any detail. There are clear trends of increasing awareness of the potential health risks of PFAS, and of increasing regulation worldwide. As research into the toxicology of PFAS progresses it is likely that existing legislation will be extended to cover a much wider range of compounds and the future of PFAS regulation in the UK will need to reflect this.

Stakeholders can be prepared for the changes ahead by keeping up to date with developments in PFAS legislation and guidance around the world as well as in the UK, and through assessing sites for potential PFAS contamination from the outset. RPS is a world-leading provider of integrated technical, advisory and project management services for PFAS management, investigation and remediation around the globe and - using our strong global connectivity and experience with PFAS - we help our clients to anticipate, avoid and mitigate any significant future impacts and protect them from unexpected costs and delays.

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