The European Chemicals Agency (Echa) has formally recommended classifying trifluoroacetic acid (TFA), a breakdown product of certain pesticides and refrigerants, as a reproductive toxicant that may impair fertility and harm an unborn child. This decision, announced 10 June and based on the conclusions of Echa’s risk assessment committee (RAC) earlier this month, could have significant implications for the regulation of drugs, pesticides and refrigerants.
The RAC opinion, based on animal studies, will be forwarded to the European Commission. Echa has also backed the RAC conclusion that TFA should be designated as persistent, mobile and toxic. The EU classes TFA as a member of the family of environmentally-persistent chemicals known as per- and poly-fluoroalkyl substances (PFAS). The recommended classification change will next be forwarded to the commission for action, and that process will likely take nine to 15 months, according to Hans Peter Arp, a chemist at the Norwegian University of Science and Technology whose research classified TFA as a global threat.
‘RAC’s decision is significant because it overturns years of messaging that TFA poses minimal toxicological concern,’ Ian Cousins, an environmental chemist at Stockholm University, tells Chemistry World. He says some voices from within academia and industry have repeatedly framed TFA as essentially harmless, but that the evidence base has now shifted.
What are PFAS?
PFAS – also known as ‘forever chemicals’ – are a family of an estimated 15,000 synthetic chemicals that have been widely used in consumer products globally since the 1950s. They are a class of chemicals that contain at least one perfluorinated methyl (–CF3) or methylene (–CF2–) group. They do not degrade easily in the environment because the carbon–fluorine bond is among the strongest in existence. The unique properties of these substances confer characteristics like repellence to oil, grease and water, as well as temperature resistance and friction reduction. This helps to create products that are non-stick and stain-resistant, for example.
However, PFAS are also highly mobile in the environment and they bioaccumulate, as well as biomagnify, up the food chain. PFOA and PFOS – the best studied of these substances – have been linked to serious health conditions like reproductive and developmental disorders, reduced immune function and certain types of cancer.
‘Recognising it as reprotoxic forces regulators to confront the long-term consequences of relying on fluorinated chemistries that inevitably degrade to TFA,’ Cousins states. ‘It should also serve as a wake-up call for industry.’ He expects strong pushback because ‘substantial commercial interests are at stake’.
TFA is a breakdown product of PFAS-based pesticides, as well as several classes of fluorinated chemicals including some drugs. The main source of TFA in the environment is fluorinated gases used as refrigerants in air conditioners and heat pumps, according to Philip Krook, spokesperson for the environmental organisation ChemSec.
Millions of tonnes of fluorinated gases are produced for refrigeration and cooling worldwide, which dwarfs the combined tonnage of all other PFAS, Cousins adds. He anticipates that the Echa move will accelerate the phase out of PFAS-based pesticides across Europe.
A ‘significant shift’
‘So far, only Norway and Denmark have adopted national bans, but a reprotoxic classification for TFA strengthens the case for broader action,’ Cousins states. ‘I expect more national bans and ultimately a European phase out, because these pesticides also contribute to long-term TFA accumulation in water resources and food chains.’
ChemSec agrees that the RAC recommendation about TFA marks ‘a significant shift’. ‘Previously considered non-harmful to humans, this re-evaluation highlights the need for stringent measures to prevent further environmental and health impacts,’ the organisation stated.
Jonatan Kleimark, director of programmes at ChemSec, said Echa has finally caught up, noting that ChemSec added TFA to its list of hazardous chemicals seven years ago. He urged the commission to ‘act immediately to stop the spread of TFA and other PFAS’. PAN Europe – the European branch of the International Pesticide Action Network – is also calling on EU authorities to take quick action to ban all PFAS pesticides that breakdown into TFA.
Once TFA enters waterways, it cannot be removed without enormous investment, Cousins warns. He suggests the only effective strategy is to shut off the major sources. ‘That means phasing out F-gases and the so-called PFAS pesticides that are major sources of TFA,’ Cousins says.
Experts have argued that the global chemistry community needs to unify its terminology when it comes to PFAS, pointing out that many competing definitions are used. For example, the OECD defines PFAS as any molecule that contains a single fully fluorinated carbon and so includes TFA, while US regulators specify that a substance must have at least two adjacent fully fluorinated carbons to be considered a PFAS and therefore do not consider TFA to be a PFAS.
‘The move by Echa to include TFA as a PFAS and to classify it as highly hazardous to early-life development is a signal that even the simplest PFAS is not without hazards to human health, especially the most vulnerable subsets of society, developing organisms,’ says Jamie DeWitt, an environmental and molecular toxicologist at Oregon State University.
Back in March, the RAC was one of Echa’s two scientific committee that supported an EU-wide restriction on the production, marketing and use of PFAS.
Recent analysis by Lancaster University estimates that chemicals to replace chlorofluorocarbons and certain anaesthetics resulted in the release of more than 335,000 tonnes of TFA between 2000 and 2022.
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