What are PFASs and where are they found?
Per- and polyfluoroalkyl substances (PFASs) are a large class of over 4000 chemical compounds. Due to their non-stick, waterproof and heat-resistant properties, PFASs have been widely used since the 1950s in various industrial fields and everyday consumer goods: textiles, food packaging, fire-fighting foams, non-stick coatings, cosmetics, plant protection products, etc.
These chemicals are very common and are classified differently according to the number of carbon atoms they contain. The more carbon atoms there are, the more persistent they are in the environment. Two of the best-known PFASs, perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS), have the highest levels of environmental persistence.
Food, especially seafood, is a significant source of human exposure to these compounds. For everyday foods, the highest concentrations of PFOA and PFOS are found in crustaceans and molluscs. Drinking water (DW) can also be a source of contamination.
In recent decades, long-chain perfluorinated compounds have been partly replaced with short-chain perfluorinated compounds, which are more mobile in soils, for example, but are still persistent and can have equivalent levels of concern.
Why are these compounds of concern and what health risks do they pose?
Given the varied uses of these chemical compounds, combined with their very high persistence, they are found in all environmental media: water, air, soil and sediment. Some accumulate in living organisms and end up in the food chain. Others, which are more mobile, are transported over very long distances via water or air and can even end up in the Arctic and Antarctic Oceans.
We can therefore be exposed to PFASs in our indoor environments, sometimes at the workplace, and through food and drinking water.
With regard to health, these chemical compounds have multiple toxic effects: they can cause an increase in cholesterol levels, lead to cancer, or have effects on fertility and foetal development. They are also suspected of interfering with the endocrine (thyroid) and immune systems. This effect of PFASs on the immune system was recently highlighted by the European Food Safety Authority (EFSA), which considers that the reduced antibody response to vaccination is the most critical human health effect.
How are PFASs regulated?
At international level
The Stockholm Convention, an international agreement (2001) on certain persistent organic pollutants, regulates several PFASs at global level: PFOS has been subject to restrictions since 2009 and the import, export and production of PFOA have been prohibited since 2020. Perfluorohexane sulfonic acid (PFHxS), its salts and related compounds are being considered for listing under the said Convention.
In Europe, several ongoing initiatives are aiming to supplement the Stockholm Convention for other classes of perfluorinated compounds.
All of the European work that has been conducted on this topic was recently highlighted in the EU Chemicals Strategy for Sustainability. This Strategy is the first step towards the zero-pollution ambition for a toxic-free environment announced in the European Green Deal.
The Strategy specifically mentions PFASs as being a priority topic for risk management. In this context, five Member States – Sweden, Norway, Denmark, the Netherlands and Germany – have published their intention to prepare a restriction dossier for all PFASs. An analysis is being undertaken to define the scope of this large-scale measure.
Regulation in drinking water
PFASs are among the new parameters introduced as part of the recasting of Directive (EU) 2020/2184 of 16 December 2020 on the quality of water intended for human consumption. Twenty PFASs are targeted and a quality limit (0.10 µg/L) has been set for the sum of these 20 compounds in drinking water. Another more global parameter, called “PFAS Total”, has also been introduced with a related quality limit of 0.50 µg/L.
Moreover, PFOS and its derivatives appear on the list of priority substances in the Water Framework Directive. They are therefore included in the EU-level monitoring and control of water bodies to improve water quality, in terms of both chemical and ecological status. In France, the amended Ministerial Order of 25 January 2010 establishes the monitoring programme for the status of water in application of Article R. 212-22 of the French Environmental Code. In this context, PFOS and several other PFASs have been monitored in aquatic environments in France since 2019.
Regulation in food-contact materials
Some PFASs are used to make food-contact materials (FCMs). There is currently no definitive list of all of the PFASs used in these materials. Nevertheless, the Organisation for Economic Co-operation and Development (OECD) carried out work in 2020 in order to list uses of these substances in FCMs. These substances are mainly used in paper/paperboard packaging as barriers or repellents against food, especially liquids. The German health agency (BfR) has listed 12 substances for this type of application. Concerning plastic FCMs (Regulation (EU) No 10/2011), the ammonium salt of PFOA is only authorised as a technological additive for use in reusable objects. This substance is also included on the ESCO list (inventory of substances used by European Union Member States) for use in printing inks.
What work has the Agency carried out with regard to these compounds?
The Agency has conducted extensive work on PFASs to:
- better understand the uses, sources of exposure (PDF) and toxicity (PDF) of these compounds;
- establish health-based guidance values for certain substances (PDF);
- assess the risks associated with the release of PFOA by the non-stick coating of kitchen utensils;
- draw up an inventory of PFAS levels in water resources and drinking water.
Because these substances cross borders and because their monitoring and assessment require considerable financial resources, studies are currently under way at European level and ANSES is involved in the expert committees in charge of assessing these dossiers as part of the REACH Regulation.
In this context, ANSES, INSERM and European partners have jointly set up an ambitious programme to monitor our exposure to chemicals. The HBM4EU European biomonitoring programme includes this large class of substances and has defined data on exposure levels across Europe. HBM4EU has multiple objectives that will address the issues raised by regulators concerning this large class: contamination levels in the population, development of biomarkers and analytical methods, research into alternatives to prohibited substances, etc.