Per and polyfluoroalkyl substances (PFAS) represent a large group of several thousands of individual compounds. According to the OECD, PFAS are defined as “any substance that contains at least one fully fluorinated methyl (CF3-) or methylene (-CF2-) carbon atom (without any H/Cl/Br/I attached to it).” i.e., with a few noted exceptions, any chemical with at least a perfluorinated methyl group (−CF3) or a perfluorinated methylene group (−CF2−) is a PFAS. This definition is also used by the European Chemical Agency (ECHA) and other agencies.
PFAS chemicals have unique properties because of the strong C-F bonds. These properties include a high resistance to external factors like extreme temperatures, pH, oxidation (non-flammable) and abrasion. Furthermore, some PFAS chemicals show high water-repellent (hydrophobic) or oil-repellent properties. Due to their unique properties PFAS have been used in a variety of industries since the 1940s (e.g. chromium plating, aerospace hydraulic fluids, fire-fighting foams and textile coatings). However, the properties of the C-F bond also make it difficult for PFAS to naturally photolyze, hydrolyse, biodegrade and metabolize, contributing to the high environmental persistence and potential bioaccumulation of PFAS. Furthermore, PFAS exposure can cause multiple toxicological effects such as hepatotoxicity, immunotoxicity, reproductive toxicity, and carcinogenicity and pose health risks to humans.
Various individual PFAS substances have been affected by global or European regulations (such as the POPs or REACH Regulations) since the early 2000s. These regulations first affected the long chain (C8) PFAS substances, such as PFOS and PFOA. As a result of the regulatory pressure, many users of these substances switched to short-chain (< C6) alternatives. This step is considered a "regrettable substitution" in retrospect, as the short chain PFAS substances also have properties of concern. As a result, these substances have been or will be the target of further regulatory measures (SVHC identification, restrictions etc.). In February 2023, ECHA published a restriction proposal for the whole group of PFAS substances (with a few exemptions). It aims to reduce PFAS emissions into the environment and make products and processes safer for people.
Due to the large number of matrices, which can contain PFAS (e.g., environmental, biological, food and consumer goods), it was already pointed out in the recent Nordic Council of Ministers reports “Analytical methods for PFAS in products and the environment” (NKE project 2021:004) and “Nordic Enforcement project on PFOS and PFOA in chemical products and articles” (NKE project 2020:014), that, for the purpose of enforcement and compliance as well as for exposure/risk management, there is a need of robust (e.g. standardized and validated) analytical methods. Thus far a broad range of analytical techniques have been developed and implemented for the analysis of these compounds.
1.1 Objectives of the project
The primary objective of this project was to examine and describe the regulatory prerequisites for ensuring effective enforcement and compliance verification of restricted PFAS in chemical products and articles. This involve assessing the current state of PFAS analysis methods, identifying the need for further method development, standardization, and validation of analyses for individual PFAS, precursor substances, total oxidizable precursor assay (TOPA), and total organic fluorine/total fluorine (including screening methods). To achieve this, the project conducted extensive literature reviews and interviews, which are compiled into this report. This report should serve as a basis to guide ongoing initiatives to restrict PFAS, including the general restriction of PFAS, and to inform stakeholders such as the European Commission, regulators and the scientific community about the concrete measures required to establish reliable analytical methods for the enforcement of PFAS regulations in the EU and the Nordic countries.
1.1.1 Methodology
Information on the current situation related to PFAS-analyses/enforcement was gathered both by a comprehensive literature search and stakeholder consultation activities.
1.1.2 Literature search
The work already carried out by VITO/Ramboll for NKE/the Norwegian Environment Agency in relation to summarizing analytical methods for PFAS was used as a starting point for a literature search. A detailed description on the methodology is given in chapter 7.1.
For the literature search the following information sources were considered:
Screening of available information within the group and known review articles
Scientific peer-reviewed literature (PubMed, EuropePMC)
Standardization bodies (incl. Draft standard methods if available)
Application notes from laboratories and suppliers of analytical equipment
Agency reports