The group of per- and polyfluoroalkyl substances (PFASs) consists of several thousand different substances. Some PFASs have been identified as Substances of Very High Concern; in many cases the effects on humans and the environment are less well known. In line with the precautionary principle, the use of PFASs should be limited to those that are essential for society, and their release into the environment must be minimised as far as possible.
Per- and polyfluoroalkyl substances (PFASs) impart water-, grease- and dirt-repellent properties to surfaces and they are characterised by high thermal and chemical stability. They are therefore often used for the coating of textiles and paper products. In combating fires involving flammable chemicals, combustibles and fuels, PFAS-based fire-fighting foams provide a good extinguishing effect and a high resistance to re-ignition. They also serve as processing aids in the production of fluoropolymers and are used in many other industrial processes and products. PFASs are composed of carbon chains of different lengths in which the hydrogen atoms are either completely (perfluorinated) or partially (polyfluorinated) replaced (substituted) by fluorine atoms. Under environmental conditions, perfluorinated substances can be formed from polyfluorinated substances through metabolic processes in organisms or abiotic degradation processes. Perfluorinated substances are extremely persistent in the environment. Two well-studied substances in the group of C8 fluorochemicals, namely perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), were also found to be toxic and to accumulate in biota via the food chain. In addition, they are now detectable in the environment in many aquatic and terrestrial organisms and in humans worldwide. Nowadays, other PFASs, especially those in the group of C6 fluorochemicals, are used instead of PFOS and its derivatives or instead of PFOA and its precursors.
1. Regulated per- and polyfluoroalkyl substances
Annex 1.16 of the Chemical Risk Reduction Ordinance (ORRChem, SR 814.81) currently regulates perfluorooctane sulfonic acid (PFOS) and its derivatives, perfluorohexane sulfonic acid (PFHxS) and its precursors, as well as perfluorooctanoic acid (PFOA) and other long-chain perfluorocarboxylic acids (C9–C14 PFCAs) including their precursors. This annex also contains consumer protection restrictions on fluoroalkylsilanols and their derivatives in preparations containing solvents applied through spraying.
PFOS and its derivatives
In 2009, the fourth Conference of the Parties to the Stockholm Convention on Persistent Organic Pollutants (POPs Convention) decided to list PFOS and its derivatives under the Convention. Restrictions came into force in Switzerland in 2011. The phase-out is now almost complete: PFOS may still be used for spray suppression in hard chrome plating in closed systems until 1 April 2024.
PFHxS and their precursors
The decision to list perfluorohexane sulfonic acid (PFHxS) and its precursors in Annex A (elimination) to the Stockholm Convention was taken at the tenth Conference of the Parties in 2022. According to the provisions of the ORRChem, which have been in force since 1 October 2022, the production, placing on the market and use of PFHxS and its precursors is prohibited. In preparations and objects, limit concentrations of 0.025 ppm of PFHxS or 1 ppm of PFHxS precursors are allowed. Mist suppression agents containing PFOS for use in hard chrome plating are exempt if they contain the shorter-chain homologue PFHxS as an unavoidable impurity due to the manufacturing process.
PFOA and precursors
In 2019, the ninth Conference of the Parties to the Stockholm Convention decided to list PFOA and its precursors in Annex A (elimination) to the Convention. In the same year, the ORRChem was amended to include general bans on the production, placing on the market and use of PFOA and its precursor compounds. The amendments came into force on 1 June 2021. The latest amendment of the ORRChem of 23 February 2022 took into account exemptions based on the current availability of alternative substances. According to these regulations, preparations and articles may contain no more than 0.025 ppm of PFOA or 1 ppm of PFOA precursors, with exemptions for certain products where a substitution or the necessary minimisation of the substances is currently not possible. Swiss regulations are in line with those laid down in Regulation (EU) 2019/1021 on persistent organic pollutants (POPs Regulation).
C9–C14 PFCAs and precursors
Perfluorocarboxylic acids with chain lengths of eight to thirteen perfluorinated carbon atoms (C9–C14 PFCAs) also have very persistent and very bioaccumulative (vPvB) and/or persistent, bioaccumulative and toxic (PBT) properties. Therefore, once the ban on PFOA and its precursors entered into force in June 2021, the aim was to prevent non-European suppliers of objects containing fluoropolymers and of finished textiles, paper and cardboard goods from switching to longer-chain PFASs or from using insufficiently purified C6 fluorotelomer derivatives that contain long-chain homologues as by-products. In accordance with the provisions of Annex XVII of the REACH Regulation, the production, placing on the market and use of C9–C14 PFCAs and its precursors were therefore also banned in Switzerland. Preparations and articles may only contain concentrations of no more than 0.025 ppm of the sum of regulated PFCAs or 1 ppm of the sum of their precursors. In principle, the same time-limited exemptions apply to C9–C14 PFCAs as to PFOA and its precursors; additional exemptions for C9–C14 PFCAs are only specified for certain fluoropolymer uses.
Fluoroalkyl silanes and their derivatives
Swiss regulations on (tridecafluorooctyl)silanetriol and its mono-, di- or tri-O-(alkyl) derivatives (TDFA) are also harmonised with those in the EU. Because the use of spray products containing TDFA and organic solvents can cause severe acute lung damage in consumers, as of 1 December 2020, spray packages (aerosol packages, pump sprays, trigger sprays) may no longer be supplied to the general public if they contain organic solvents in combination with more than 2 ppb of TDFA. In order to ensure that professional users of these C6 fluorchemicals are aware of the specific hazard associated with the use of these mixtures, it was also
stipulated that spray packages must be labelled ‘Fatal if inhaled’.
2. Updating legislation
Because of their extreme persistency in the environment and high mobility in soils and waters, there is concern that also shorter-chain perfluorocarboxylic acids could be problematic for the environment and human health in the long term. Accordingly, in accordance with the EU, measures for perfluorohexanoic acid (PFHxA) and its precursors (C6 fluorchemical products) are under consideration in Switzerland. Work is also under way in the EU to ban all PFASs in fire-fighting foams and, beyond that, to ban all PFASs for use in all other applications unless they are indispensable to society. The aim in terms of the precautionary principle is that the use of PFASs is limited to such uses in the future (‘essential uses’).
Last modification 24.10.2022