Sostanze perfluoroalchiliche (PFAS)

Le sostanze perfluoroalchiliche (PFAS) costituiscono una grande famiglia di migliaia di sostanze chimiche sintetiche ampiamente utilizzate nell’intera società e riscontrate nell’ambiente. 

Tutte contengono legami carbonio-fluoro, che sono tra i legami chimici più forti nella chimica organica. Ciò significa che resistono alla degradazione quando utilizzate oltre che nell’ambiente. La maggior parte delle PFAS è anche facilmente trasportabile nell’ambiente, coprendo lunghe distanze dalla fonte del rilascio. 

Le PFAS sono state frequentemente osservate nella contaminazione di suolo, acque sotterranee e acque superficiali. La bonifica di siti contaminati è tecnicamente difficile e dispendiosa. Se tali rilasci proseguono, continueranno ad accumularsi nell’ambiente, nell’acqua potabile e negli alimenti.

What are PFAS and what are they used for?

PFAS have a wide range of different physical and chemical properties. They can be gases, liquids, or solid high-molecular weight polymers. Some PFAS are described as long-chain or short-chain, but this does not cover all of the different kinds of structures that are present in the PFAS class, which is very diverse. PFASs can be sorted in many ways based on their structure.

PFAS are widely used as they have unique desirable properties. For instance, they are stable under intense heat. Many of them are also surfactants and are used, for example, as water and grease repellents.

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

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

What are the concerns?

The majority of PFAS are persistent in the environment. Some PFAS are known to persist in the environment longer than any other synthetic substance. As a consequence of this persistence, as long as PFAS continue to be released to the environment, humans and other species will be exposed to ever greater concentrations. Even if all releases of PFAS would cease tomorrow, they would continue to be present in the environment, and humans, for generations to come.

The behaviour of PFAS in the environment means that they tend to pollute groundwater and drinking water, which is difficult and costly to remediate. Certain PFAS are known to accumulate in people, animals and plants and cause toxic effects. Certain PFAS are toxic for reproduction and can harm the development of foetuses. Several PFAS may cause cancer in humans. Some PFAS are also suspected of interfering with the human endocrine (hormonal) system.

PFAS are released into the environment from direct and indirect sources, for example, from professional and industrial facilities using PFAS, during use of consumer products (e.g. cosmetics, ski waxes, 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 PFAS regulated in the EU?
Globally regulated PFAS 
Since 2009, perfluorooctane sulfonic acid and its derivatives (PFOS) have been included in the international Stockholm Convention to eliminate their use. PFOS has been restricted in the EU for more than 10 years already, under the EU’s Persistent Organic Pollutants (POPs) Regulation.
The Stockholm Convention also 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.

In June 2022, the Stockholm Convention parties decided to include PFHxS, its salts and related compounds in the treaty. The Commission added the substance group in the EU's POPs Regulation in May 2023 and the regulation entered into force on 28 August 2023.  

Long-chain perfluorinated carboxylic acids (C9-21 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 are 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. 
Germany has proposed a further restriction for undecafluorohexanoic acid (PFHxA), its salts and related substances. This proposal was evaluated by ECHA's scientific committees in December 2021. The EU Member States voted in favour of the Commission's proposal in February 2024. The restriction will now be scrutinised by the European Parliament and Council before it can be adopted.

The national authorities of Germany, Denmark, the Netherlands, Norway and Sweden are proposing a restriction covering a wide range of PFAS uses – in support of the statements made in the Environment Council in December 2019. They submitted their proposal to ECHA in January 2023, and ECHA’s scientific committees are now evaluating it.

Furthermore, ECHA introduced in January 2022 a restriction proposal for PFAS used in firefighting foams. ECHA's scientific committees supported the proposal in their opinions finalised in June 2023. The European Commission together with the EU countries will decide on the restriction in due course. This use is not included in the universal PFAS restriction proposed by the five national authorities.

Substances of very high concern under REACH
A number of PFAS are on the REACH Candidate List of substances of very high concern (SVHC), for example PFOA, perfluorinated carboxylic acids (C9-14 PFCAs) and PFHxS.
In June 2019, January 2020 and January 2023, three groups of PFAS were identified as SVHCs. 
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; and 
  • perfluoroheptanoic acid (PFHpA) and its salts.
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). These PFAS were identified as of equivalent concern to carcinogens, mutagens and reprotoxicants (CMRs) and persistent, bioaccumulative and toxic/very persistent and very bioaccumulative (PBTs/vPvBs) chemicals.

Evaluation of substances under REACH
Several additional PFAS 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 PFAS 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; and
  • perfluoroheptanoic acid (PFHpA).
RAC has also issued an opinion on the harmonised classification and labelling for  3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctan-1-ol (6:2 FTOH). This opinion is 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 countries, ECHA and the European Commission has, since 2014, screened data on PFAS 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 thousand individual PFAS on the EU market. These belong to a variety of subgroups. Assessing and, where relevant, managing risks subgroup by subgroup would require a considerable amount of time. Therefore, ECHA acknowledges that a holistic group approach to 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 PFAS, 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 PFAS. 
PFAS and food
PFAS 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. 
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. 
According to EFSA experts, the main contributors to human dietary exposure include fish meat, fruit, fruit products, eggs and egg products. Some PFAS, especially those having long chains, can accumulate in human bodies. EFSA’s scientific advice will support risk managers in their decisions on how best to protect consumers from exposure to PFAS through food. 

Video on the European ban on PFAS prepared by the The Dutch National Institute for Public Health and the Environment (RIVM). Copyright: RIVM.

PFAS infographic


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