Substances perfluoroalkylées (PFAS)

Les substances perfluoroalkylées (PFAS) forment une grande famille de plusieurs milliers de produits chimiques synthétiques qui sont couramment utilisés dans l’ensemble de la société et que l’on retrouve dans l’environnement. 

Elles contiennent toutes des liaisons carbone-fluor, qui comptent parmi les liaisons chimiques les plus fortes de la chimie organique. Cela signifie qu’elles ne se dégradent pas après utilisation ou rejet dans l’environnement. La plupart des PFAS sont également facilement transportées dans l’environnement sur de longues distances, loin de leur source d’émission. 

On a fréquemment observé une contamination des eaux souterraines, des eaux de surface et du sol par les PFAS. Le nettoyage des sites pollués est techniquement difficile et coûteux. Si elles continuent à être rejetées, elles ne cesseront de s’accumuler dans l’environnement, dans l’eau potable et dans les aliments.

What are PFASs and what are they used for?

PFASs have a wide range of different physical and chemical properties. They can be gases, liquids, or solid high-molecular weight polymers. Some PFASs are described as long-chain or short-chain molecules, but this does not cover all of the different structures in the PFAS class. PFASs can also be sub-grouped in other ways based on their structure. 

PFASs are widely used as they have unique desirable properties. For instance, they are stable under intense heat. Many of them also have surfactant properties and function, e.g. as water and grease repellents.

Some of the major industry sectors using PFASs include aerospace and defence, automotive, aviation, food contact materials, textiles, leather and apparel, construction and household products, electronics, fire-fighting, food processing, and medical articles.

Over the past decades, global manufacturers have started to substitute long-chain PFASs with other PFASs or with fluorine-free substances. This trend has been driven by the fact that the harmful effects of long-chain PFAS on human health and the environment were the first that were recognised by scientists and governments around the globe. As the focus shifted to other PFASs these were also found to have properties of concern.

What are the concerns?

All PFASs are highly persistent in the environment. In fact, they are known to persist in the environment longer than any other man-made substance. As a consequence of this persistence, as long as PFASs continue to be released to the environment, humans and other species will be exposed to ever greater concentrations of PFASs. Even if all releases of PFASs would cease tomorrow, they would continue to be present in the environment, and humans, for generations to come.

Their release and mobility in water and air causes contamination to groundwater and drinking water, which is difficult and costly to avoid. Certain PFASs are known to accumulate in living things and cause toxic effects. Certain PFASs are toxic for reproduction and can harm the development of foetuses. Several PFASs may cause cancer in humans. Some PFASs are also suspected of interfering with the human endocrine (hormonal) system. 

PFASs are released into the environment from direct and indirect sources, for example, from professional and industrial facilities using PFASs, during use of consumer products (e.g. cosmetics, ski waxes or clothing) and from food contact materials. Humans can be exposed to them every day at home, in their workplace and through the environment, for example, from the food they eat and drinking water. 

How are PFASs regulated in the EU?
 
Globally regulated PFASs 
 
Since 2009, perfluorooctane sulfonic acid and its derivatives (PFOS) have been included in the international Stockholm Convention to eliminate their use. PFOS has already been restricted in the EU for more than 10 years, under the EU’s Persistent Organic Pollutants (POPs) Regulation
 
In addition, the Stockholm Convention regulates the global elimination of perfluorooctanoic acid (PFOA), its salts and PFOA-related compounds. PFOA has been banned under the POPs Regulation since 4 July 2020.
 
Perfluorohexane sulfonic acid (PFHxS), its salts and related compounds as well as perfluorinated carboxylic acids (C9-14 PFCAs) are being considered for inclusion in the Stockholm Convention and consequent global elimination. 
 
REACH restrictions
 
Perfluorinated carboxylic acids (C9-14 PFCAs), their salts and precursors will be restricted in the EU/EEA from February 2023 onwards following a decision taken by the European Commission on a proposal by the German and Swedish authorities. 
 
Norway has proposed a restriction on perfluorohexane-1-sulphonic acid (PFHxS), its salts and related substances. ECHA's scientific committees gave their opinion supporting the restriction in June 2020 and the proposal is currently with the European Commission for decision making together with the EU countries.
 
Germany has proposed a further restriction for undecafluorohexanoic acid (PFHxA), its salts and related substances. This proposal was also supported by ECHA's scientific committees in December 2021. The European Commission together with the EU countries will decide on the restriction in due course.
 
The Netherlands, Germany, Norway, Denmark and Sweden are preparing a restriction proposal to cover a wide range of PFAS uses – in support of the statements made in the Environment Council in December 2019. They are expected to submit the proposal to ECHA in January 2023. 
 
Furthermore, ECHA submitted in January 2022 a restriction proposal for PFASs used in firefighting foams. A consultation on this proposal is open from 23 March until 23 September 2022. This use is not included in the wider PFAS restriction being prepared by the five European countries.
 
Substances of very high concern under REACH
 
A number of other PFASs are on the REACH Candidate List of substances of very high concern (SVHC).
 
In June 2019 and January 2020, two PFAS groups were identified as SVHCs. The SVHC identification was based on their persistence, mobility and toxicity, which were considered to pose a threat to human health and wildlife when exposed through the environment (including through drinking water). This SVHC identification identified these PFASs as of equivalent concern to carcinogens, mutagens and reprotoxicants (CMRs) and persistent, bioaccumulative and toxic/very persistent and very bioaccumulative (PBTs/vPvBs) chemicals. 
 
These groups are:
 
  • 2,3,3,3-tetrafluoro-2-(heptafluoropropoxy)propionic acid, its salts and its acyl halides (HFPO-DA), a short-chain PFAS substitute for PFOA in fluoropolymer production, was the first substance added to the Candidate List. Its ammonium salt is commonly known as GenX. [General Court judgment]
  • perfluorobutane sulfonic acid (PFBS) and its salts, a replacement of PFOS.  
 
Evaluation of substances under REACH
 
Several additional PFASs are on the list for evaluation (Community rolling action plan) over the coming years or have already been evaluated. The evaluation aims to clarify initial concerns on the potential risk to human health or the environment that manufacturing or using these substances could pose.
 
Classification, Labelling and Packaging (CLP) Regulation
 
A few PFASs already have a harmonised classification and labelling under the CLP Regulation. These include:
 
  • perfluorooctanoic acid (PFOA);
  • ammonium pentadecafluorooctanoate (APFO);
  • perfluorononan-1-oic acid (PFNA) and its sodium and ammonium salts;
  • nonadecafluorodecanoic acid (PFDA) and its sodium and ammonium salts.
 
RAC has issued opinions on harmonised classification and labelling for perfluoroheptanoic acid (PFHpA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol (6:2 FTOH). These opinions are currently in the European Commission for decision-making together with the EU countries for inclusion into the CLP Regulation.
 
Assessing groups of PFAS
 
An informal coordination group of several EU Member States, ECHA and the European Commission has, since 2014, screened data on PFASs contained in ECHA’s registration database and coordinated group-based regulatory work.
 
Despite an efficient approach compared to regulating substance by substance, work has only been able to cover the PFAS groups of highest urgency due to the very large number of PFAS. 
 
ECHA’s database contains information of several thousands individual PFASs on the EU market. These belong to a variety of subgroups and it seems, based on the experience that it would take too long to assess and, where relevant, manage risks subgroup by subgroup. Therefore, ECHA acknowledges that a holistic group approach to the regulatory assessment and risk management needs to be explored.
 
The EU’s chemicals strategy for sustainability places PFAS policy front and centre. The European Commission commits to phasing out all PFASs, allowing their use only where they are proven to be irreplaceable and essential to society.  
 
Drinking Water 
 
The recast of the Drinking Water Directive, which took effect on 12 January 2021, includes a limit of 0.5 µg/l for all PFAS. This is in line with a grouping approach for all PFASs. 
 
PFASs and food
 
PFASs are released into the environment through industrial manufacturing not directly linked to food production and through the use and disposal of PFAS-containing products.  However, as often with persistent pollutants, they end up in food. The main contributors to human dietary exposure are certain vegetables but drinking water is also an important source. Some PFASs also accumulate to human bodies through fish and seafood, meat and meat products, eggs, milk and dairy products. 
 
In September 2020, the European Food Safety Authority (EFSA) set a new safety threshold for the main perfluoroalkyl substances that accumulate in the body: perfluorooctanoic acid (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS). The threshold – a group tolerable weekly intake (TWI) of 4.4 nanograms per kilogram of body weight per week – is part of a scientific opinion on the risks to people’s health from the presence of these substances in food. EFSA’s scientific advice will support risk managers in their decisions on how best to protect consumers from exposure to PFASs through food.

 

Video on the European ban on PFASs prepared by the The Dutch National Institute for Public Health and the Environment (RIVM). Five European states are expected to submit their proposal to restrict all PFASs in the EU by 13 January 2023. Copyright: RIVM.

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