Poly- and perfluoroalkyl substances (PFAS)

Introduction

• Per- and polyfluoroalkyl substances (PFAS) are a large group of chemicals with widely varying properties. They are regulated under the Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation, plant protection product (PPP) regulations, and other sector-specific legislation such as those governing biocides and pharmaceuticals.

• PFAS are used across a broad range of industries and applications.

• Only a small number of PPPs approved for use in the United Kingdom (UK) and European Union (EU) contain PFAS. PPP regulations only allow approval of active substances that do not harm human health or cause unacceptable environmental effects.

• Where PFAS levels have been measured (in microgrammes per litre), it is essential to identify the precise source(s), including historic uses, due to their widespread application in industrial and domestic settings.

• In the UK and EU, regulatory risk analyses have identified firefighting foams as the highest risk area, with consultations underway regarding restrictions on their use.

• Environmental monitoring of PFAS continues in the UK and globally to assess levels, impacts, and sources. Consequently, guidance or legislation may evolve to address any identified risks to human health and/or the environment.

What are PFAS?

PFAS are synthetic organofluorine chemicals that have been widely used since the 1940s. Thousands of substances fall under the PFAS classification.
All PFAS contain at least one fully fluorinated methyl (–CF₃) or methylene (–CF₂–) group.
The carbon-fluorine (C–F) bond is exceptionally strong, making PFAS resistant to chemical degradation, water, and high temperatures.
Environmental monitoring includes ultra-short chain PFAS such as trifluoroacetic acid (TFA), conducted by regulators and other organisations.

Where are PFAS used?

PFAS possess grease, oil, and water-repellent properties. They are used in a wide array of consumer and industrial applications, including firefighting foams, metal finishing and plating, hydraulic fluids, fluoropolymer production, and some PPPs.¹
In domestic settings, PFAS are found in certain food packaging materials (for water and grease resistance), waterproof textiles and leather (e.g. carpets and furniture), non-stick cookware, paints and varnishes, cleaning products, and personal hygiene items (e.g. cosmetics, shampoos, dental floss).
Due to their extensive use, PFAS can readily enter the environment during manufacture, formulation, use, or disposal of PFAS-containing products.

Regulations Applying to PFAS

Most PFAS are industrial and consumer chemicals regulated under the EU REACH² and UK REACH³ frameworks.
PFAS may also be indirectly regulated under other legislative regimes, such as those governing PPPs. PPP regulations impose strict criteria for persistence, mobility, and toxicity (Annex II of the Regulation on placing PPPs on the market⁴). If these criteria are exceeded, the active substance is not approved for use in the EU or Great Britain.

PFAS Properties

The length of the fluorinated carbon chain affects the physicochemical properties of PFAS, influencing environmental behaviour, bioaccumulation, and (eco)toxicity.
Some PFAS degrade partially into perfluoroalkylated acids (PFAAs), such as perfluoroalkyl sulfonic acids (PFSAs) and perfluoroalkyl carboxylic acids (PFCAs), which are highly resistant to further degradation. PFAAs can persist in the environment for decades or longer.
Due to this persistence, some media refer to PFAS as ‘forever chemicals’. However, persistence varies significantly across the PFAS group.

UK Regulators’ Position on PFAS

Drinking Water Inspectorate (DWI)

Currently, PFAS are not included in the Water Quality Regulations for drinking water in England and Wales.
However, due to their persistence and widespread use, the DWI issued updated guidance⁵ in March 2025 to all water companies regarding PFAS sampling.
Water companies now monitor and report the ‘sum of PFAS’ based on 48 named PFAS chemicals listed by the DWI. This approach exceeds Scotland’s position, where a 0.1 µg/l limit applies to a smaller group of PFAS.
If PFAS levels exceed 0.1 µg/l, water companies must take action to reduce them.
During 2024 there were no samples reported above 0.1µ/l for any treated water being supplied to consumers. In fact, 96% of samples were below the detection limit of the analytical methods used.

Health and Safety Executive (HSE)

In 2023, the HSE, supported by the Environment Agency, assessed regulatory management options⁶ to address PFAS risks.
The assessment identified potential restrictions in the following areas (subject to further evidence and consultation):

• Use and disposal of firefighting foams (FFF), where non-PFAS alternatives are available

• Other wide dispersive uses such as the application of coatings or use of cleaning agents

• Manufacture and marketing of consumer products including textiles, upholstery, leather, carpets, paints, varnishes, waxes and polishes and cleaning products

The HSE launched a public consultation⁷ in August 2025 on restricting PFAS in FFF.

Department for Environment, Food and Rural Affairs (Defra) / Chemicals Regulation Division (CRD)

CRD follows Defra’s policy guidance on PFAS in PPPs.
Currently, Defra has no policy proposals regarding PFAS in PPPs.

Monitoring by Other Organisations

In addition to regulatory monitoring, charities and researchers across the EU (including Great Britain) have conducted environmental monitoring and laboratory studies.
Findings show PFAS and TFA are present at many tested sites.
Data analysis is ongoing to determine sources, as some of the highest levels are detected around large urban areas and other areas where use of PPPs containing PFAS is minimal.

EU Position on PFAS

The European Chemicals Agency (ECHA) has published an updated proposal⁸ to restrict PFAS under REACH.
ECHA’s Risk Assessment Committee (RAC) and Socio-Economic Analysis Committee (SEAC) are evaluating the proposal, with opinions expected in 2026.
ECHA has proposed restrictions on PFAS in FFF⁹ and is reviewing the classification of TFA¹⁰ at the request of the German competent authority. The outcome is expected in October 2026.

Unilateral Action by Denmark

Denmark implemented national action on certain PFAS in July 2025.
Groundwater screening in 2020 detected TFA in 89% of wells.
A non-regulatory study (2022–2024) assessed whether TFA could form in soils from degradation of eight PPP active substances sold in Denmark: diflufenican, fluopyram, fluazinam, mefentrifluconazole, tau-fluvalinate, and historically fluazifop-P-butyl and trifluralin.
Results showed varying levels of TFA formation.
Denmark’s legislation prohibits approval of products containing active substances or metabolites with a half-life exceeding 180 days, due to its reliance on groundwater for drinking water and a prevention-based pollution policy.¹¹
Withdrawal notices were issued for products identified as producing TFA, with final use dates ranging from December 2025 to August 2026.