Understanding more about exposure to and the hazards of PFASs

Per- and polyfluoroalkyl substances, collectively known as PFASs, are chemicals that share one main characteristic: they are very persistent in the environment. This persistence means they can be found in all environmental compartments. Given the very large number of substances involved, the major challenge is to prioritise actions to prevent or limit health and environmental risks. PFASs have been a topic of interest for ANSES for a long time. The Agency carries out several activities in this area: characterising the PFASs most commonly found, determining the levels of contamination to which people are exposed, and identifying the most toxic substances. Below is an overview of this work.

Reducing PFAS emissions at the source

PFASs have one thing in common: they are very persistent in the environment due to the carbon-fluorine bonds contained in a carbon chain that varies in length. Therefore, as with all substances that tend to accumulate in ecosystems and the food chain, the priority is to act at the source by limiting their emissions. At international level, certain PFASs deemed highly problematic, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), have already been heavily restricted or even banned.

In the European Union, a restriction proposal supported by five Member States is currently being considered by the European Chemicals Agency (ECHA), which regularly reports on the progress of its work. It proposes a ban in Europe on the manufacture and placing on the market of substances, mixtures and articles containing PFASs. These substances are grouped together not because they have the same level of toxicity, but because they are highly persistent in the environment. This is the first time that a restriction dossier has covered such a vast class of substances (several thousand substances). The aim is to avoid a cascade of substitutions for substances in the same class. The restriction dossier is taking time to process, because it is necessary to review all the various areas in which PFASs are used and applied.

As part of this restriction proposal, some exemptions, most of which are time-limited, will be examined for certain essential uses depending on the availability of alternatives. ANSES is closely monitoring and supporting this restriction proposal and contributed to the public consultation organised to that end in 2023. It is taking part in the European work that has been initiated to examine this restriction proposal under the REACH Regulation.

However, even in the event of a ban on the manufacture and placing on the market of PFASs, it will be necessary to continue monitoring these substances in various compartments due to their persistence in the environment. This is why ANSES’s activities and expert appraisal work are focusing on identifying and recommending actions targeting those substances that are the most prevalent in the environment and the most problematic for health and the environment.

Drawing up an inventory of PFAS contamination levels in France

ANSES has begun work to determine levels of contamination:

  • In general: planned for the end of 2025, an overall review is under way to describe PFAS contamination levels in water, food, indoor air and dust (including occupational exposure) and soil, as well as the presence of these substances in consumer products. This review, which will require an inventory of ongoing monitoring schemes, will provide an opportunity to propose changes to these schemes as necessary.
  • For drinking water: the new exploratory campaign launched in spring 2024 by the ANSES Laboratory for Hydrology is focusing on several PFASs, including the 20 identified in Directive (EU) 2020/2184, known as the Drinking Water Directive. This type of campaign is intended to collect data on emerging compounds that are not regulated or are poorly understood, to improve health risk assessment and water monitoring. The results will be published by 2026.
  • In food: around 20 PFASs have been included in ANSES's Total Diet Study, the third edition of which is currently under way. These data will help to clarify the population's dietary exposure to these substances. The results are expected in 2026.
  • The Agency will also take account of the data collected as part of the 2024 interministerial action plan on PFASs.

Identifying the most prevalent and toxic PFASs

As PFASs encompass several thousand substances – between 4,000 and 10,000 – it is necessary to prioritise the assessment of those that are the most hazardous and the most prevalent in the environment. To do this, the Agency has developed and is currently refining a method for prioritising PFASs, which will be used to draw up a ranked list of the substances to be monitored as a priority in various environmental compartments. These substances will be added to the list of toxic and persistent pollutants – dioxins, PBBs, flame retardants, etc. – that are subject to special monitoring and management measures when the threshold levels are exceeded. This list will also be used to identify substances requiring the development of scientific benchmarks to support monitoring activities.

The aim of the scientific work in progress is to identify those PFASs for which it is necessary to develop benchmarks for risk assessment or produce scientific data, also taking account of the activities carried out by ANSES’s international counterparts.


Developing useful benchmarks for risk assessment

For the highest-priority substances, without health reference values, it is difficult to assess the risks associated with exposure and help the public authorities set concentrations that are not to be exceeded.

For greater efficiency, the Agency strives to take better account of the work and initiatives of other counterpart agencies and organisations. It has already identified the existing reference values published in other European countries or at international level, for the 20 PFASs to be monitored in drinking water. It is continuing this work with a critical analysis of the current toxicity reference values (TRVs). For those TRVs that do not exist, or are deemed inappropriate, the Agency will propose new ones. The health authorities (Ministry of Health, regional health agencies, etc.) will then establish management values based on these long-term oral TRVs.

What is a TRV?

Toxicity reference values, or TRVs, establish a relationship between a quantity of a chemical and a harmful effect or the probability of an effect occurring. These toxicological indicators are intended to protect the population as a whole, including susceptible groups such as children, pregnant women, and sick people. There are external TRVs specific to an exposure route (oral, respiratory, dermal, etc.) as well as internal TRVs (values measured in a biological matrix such as blood).

Taking action at national level

ANSES is involved as a contributor or leader in several actions of the 2024 interministerial action plan on PFASs, alongside other health and environmental stakeholders.

Concerning water safety, it works closely with the French High Council for Public Health (HCSP) to support the public authorities in managing the risks associated with PFASs. Moreover, the ANSES Laboratory for Hydrology works to improve the reliability of water analysis results and their interpretation by accredited laboratories.

ANSES also contributes to improving the quality of the results produced by approved laboratories by providing technical support. Furthermore, it is involved in standardisation work at the national, European and international levels to develop robust analytical standards that meet regulatory requirements and ensure the production of comparable data.

Working in Europe

The concerns raised by PFASs are not specific to France. The study of substances in this class has been included in the European Partnership for the Assessment of Risks from Chemicals (PARC). Coordinated by ANSES, this major project is seeking to develop next-generation chemical risk assessment in order to better protect health and the environment at European level.

The Agency also exchanges information with its European counterparts and with the European Food Safety Authority (EFSA) with regard to health challenges and the methods developed to assess these substances.

In addition, ANSES supports the Directorate General for Health in the European expert groups aimed at establishing the technical guides necessary for the implementation of the Drinking Water Directive.

PFASs: very persistent chemicals
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Going further

PFASs: very persistent chemicals

What are the sources of exposure to PFASs ? Why are they of concern for public health? How are PFASs regulated? Find out in this article.