Sustancias químicas perfluoralquiladas (PFAS)

Las sustancias perfluoroalquiladas y polifluoroalquiladas (PFAS) son una gran familia de sustancias químicas sintéticas ampliamente utilizadas por toda la sociedad que se encuentran en el medio ambiente. 

Todas ellas contienen enlaces carbon-flúor, que son unos de los enlaces químicos más fuertes de la química orgánica. Esto significa que resisten la degradación cuando son utilizados y también cuando se encuentran en el medio ambiente. La mayoría de las PFAS se propagan fácilmente en el medio ambiente, cubriendo grandes distancias desde la fuente de liberación. 

Se ha podido comprobar con frecuencia que las PFAS contaminan las aguas subterráneas y superficiales y el suelo. La limpieza de zonas contaminadas es cara y técnicamente difícil. Si continúan las liberaciones, las PFAS continuarán acumulándose en el medio ambiente, el agua potable y los alimentos.

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. They are sometimes described as long-chain and short-chain as a way to group PFAS that may behave similarly in the environment. PFAS are also grouped into subgroups in various other 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 also have surfactant properties and function, e.g., as water and grease repellents. 

Some of the major industry sectors using PFAS include aerospace and defence, automotive, aviation, 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 PFAS with shorter-chain PFAS or with non-fluorinated substances. This trend has been driven by the fact that the undesired effects of long-chain PFAS on human health and the environment were assessed and recognised first by scientists and authorities around the globe. Short-chain PFAS can also have similar or other properties of concern. 

 

What are the concerns?

All PFAS 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 PFAS continue to be released to the environment, humans and other species will be exposed to ever greater concentrations of PFAS.  Even if all releases of PFAS 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 PFAS are known to accumulate in the bodies of living things and cause toxic effects. Certain PFAS are toxic for reproduction and can harm the development of foetuses. Several PFAS have been demonstrated to cause cancer. Some PFAS are also suspected of interfering with the human endocrine (hormonal) system, but testing in this area is ongoing. 

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 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 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 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 also submitted a further restriction proposal for undecafluorohexanoic acid (PFHxA), its salts and related substances. 
 
The Netherlands and Germany, with support from 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 by 15 July 2022. 
 
Furthermore, ECHA will submit a restriction proposal in January 2022 for PFAS used in firefighting foams. This use is not included in the wide PFAS restriction being prepared by the five European countries. 
 
Substances of very high concern under REACH
 
A number of other PFAS 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 PFAS 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.
  • perfluorobutane sulfonic acid (PFBS) and its salts, a replacement of PFOS.  
 
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.
 
Perfluoroheptanoic acid has been proposed for harmonised classification and labelling and is in opinion development at the moment.
 
Grouping approach 
 
An informal coordination group of several EU Member States, 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 over 2 000 individual PFAS 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, as requested in the proposal for an EU strategy for PFAS, submitted to five Commissioners from several Member States in December 2019.
 
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 the food chain. The main contributors to human dietary exposure are certain vegetables but drinking water is also an important source. Some PFAS 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 PFAS through food.

 

 

How is the EU making sure PFAS chemicals don’t stick around?

Podcast: interview with Bjorn Hansen, ECHA's Executive Director

Where exactly are PFAS used, what are the concerns and what is the EU doing about them? Listen to our podcast to find out.

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