The issue of PFAS is nothing new, as those who’ve had the chance to see the film Dark Waters(1) will know well. What is new however is that through advances in research, a growing number of these substances are now restricted, or even banned or soon to be so.
What exactly are we talking about?
PFAS, comprising per- and polyfluoroalkyls, make up a very large group of chemicals first created at the start of the 1940s. Today, these substances exist in their thousands. These synthetic chemicals are particularly resistant to water and oils, are both chemically and thermally extremely stable and possess low surface tension. PFOA and PFOS are the most commonly found, and the most studied along with PFCA and PFHx (2).
The strong stability of the carbon-fluorine bond which characterises PFAS endows them with great persistence in every environment: they don’t degrade, attracting the term “forever chemicals” due to their ability to accumulate in organisms without being metabolised.
Where do they come from and what are they used for?
There exist both direct and indirect sources of PFAS. Direct sources are industrial processes, primarily the fluorochemical industries which produce them. PFAS are then provided as additives or as auxiliary agents for the production of fluoropolymers used in the aeronautical, automotive, electronic, paper, food packaging, and textile industries (for example, the production of water- or oil-resistant clothing, stain-proof, anti-adhesive or flame-retardant garments; the production of raw materials for components: bearings and low-friction joints, containers, cable and electronic components, etc.). They are also used as co-components in some phytosanitary or maintenance products (e.g. floor polishes), in metal treatment, in paints and, above all, in fire-fighting foams. These foams are found primarily in fire training centres, petroleum refining and storage facilities, airports, and across a wide range of sites that have suffered a fire.
Indirect PFAS sources relate to the use of products containing them, and the storage and processing of their wastes (landfill effluents, water treatment plants), as well as atmospheric emissions (fruit and vegetables, water, animal products etc.).
Simply put, PFOA and PFOS are found everywhere in our environment: from food packaging and construction materials to our carpets and rugs, kitchen utensils (especially in non-stick pans)(3), waterproof clothing and leather goods, amongst others.
What are the impacts?
As a result of their persistence, mobility and toxicity, PFAS pollute water and the wider environment. They can then be consumed by humans and animals through food or water. In June 2019 a large proportion of these PFAS were added to the European Chemicals Agency (ECHA) list of SVHC, or “Substances of Very High Concern”. Some are reprotoxic, potentially able to affect foetal development (altering metabolism and liver function). Others are suspected of interfering with the endocrine system or of causing cancer. Moreover, last November IARC (the International Agency for Research on Cancer at the World Health Organization) classified PFOA as “carcinogenic to humans” and PFOS as “possibly carcinogenic to humans”, following an in-depth review of the scientific literature.
What alternatives are there?
Inéris, which has been working on PFAS since the 2010s (cf. eco-toxicological and technical-economic datasheets, and the Aquaref methodology sheets for sludges, biota and untreated water), has seen acceleration since 2021 with, among others, the highlighting of the presence of PFAS around French industrial sites and demands from several European countries to ECHA for universal restriction (see below). In addition to the exposing and assessing of risks, along with environmental surveillance and impact studies (with the development of sampling methods, analysis and transfer characterisation), the Institute looks at the use of PFAS and options for their substitution. Where for some, it is possible to simply use substances with shorter carbon-fluorine bonds, for others it is important that real alternatives be identified. That’s the purpose of the PFAS and PMT section of the website dedicated to the substitution of chemical substances, a recent addition to the sections covering bisphenols, phthalates and alkylphenol ethoxylates. The idea is initially to offer alternatives for applications that represent a significant source of emissions and distributed exposures, such as fire-fighting foams and paper and textile coatings, and to illustrate examples of substitution solutions derived from practices or concrete experiences in companies. The website then makes available all the information that could contribute to early prevention of environmental contamination by PMT/vPvM(4) substances.
Note also that the OECD is undertaking an in-depth analysis and inventory of approaches shared by different countries to underpin the substitution of chemical substances of concern, as well as the evaluation of alternatives promoted by these countries. The second edition of this study was published in March 2023.
Are we heading for a total ban?
It has not been possible to produce, market or use PFOS in the EU since 2009 through the application of the POP (Persistent Organic Pollutants) Regulation, mirroring the Stockholm International Convention of 2001. As of July 2020, this is also the case for PFOA, their salts and their related compounds. Additionally, PFCA, their salts and their precursor compounds have been “restricted” in the EU since February 2023: they may not be marketed, or used in most of their applications – with certain exceptions such as textiles for protective clothing, and in semi-conductor fabrication processes. In the same way, PFHx, their salts and derivative compounds have been regulated since August 2023 and this will soon also be the case for PFHxA.
In parallel with this, the December 2020 Drinking Water Directive (DWD), transposed in France from December 2022, fixes the maximum content for drinking water at 0.50 µg/l for all PFAS or 0.10 µg/l for the total of 20 PFAS classified as substances of concern. As stated in the Ministerial Action Plan on PFAS, launched in January 2023 (see box), “This transposition brings with it an obligation to monitor these parameters in the DWD as from 2026, the limit on quality, as such, being introduced into the French regulatory framework as from 2023 to enable local health authorities to have available a management value for planned research that has been set based on detection and local contexts.” Basically, since January 2023 every time the limit has been exceeded has had to be noted, and on 1 January 2026 PFAS will be integrated into the DWD regulatory health monitoring programme. The analytical toolkit will be provided over the course of 2024 by ANSES, the French National Agency for Food, Environmental and Occupational Health & Safety.
On a wider scale, in 2023 a number of EU countries (Germany, Denmark, the Netherlands, Sweden), as well as Norway, began to request restrictions on many PFAS uses. The study is underway at ECHA. For many, regulation has to be by product family rather than by individual product. Watch this space…
1) “Dark Waters” by Todd Haynes traces the struggle of a lawyer taking on a huge chemical industry opponent for water poisoning by a PFOA (C8) in the State of Virginia in the 1990s.
2) PFOA: perfluorooctanoic acid; PFOS: Perfluorooctane sulfonic acid; PFCA: perfluorocarboxylic acid and PFHxS: Perfluorohexane sulfonic acid; PFHxA: Perfluorohexanoic acid.
3) With regard to non-stick pans, note that some brands as of now state whether or not they contain PFOA or PFOS.
4) PMT: persistent mobile and toxic substances and vPvM: very persistent and very mobile substances.