The emerging TFA risk: A new constraint on fluorinated pesticides in Europe
Gordon Amour of AgbioInvestor looks at regulatory signals, national actions and strategic implications of TFA restrictions for the EU crop protection market
Trifluoroacetic acid( TFA) is a persistent metabolite formed through the degradation of certain active substances used in plant protection products( PPPs) and biocidal products and from the breakdown of other perand polyfluoroalkyl substances( PFAS). It is also used as a precursor in chemical manufacturing and can occur naturally in the environment. Because it stems from various sources, TFA presents challenges in terms of characterising its presence and build-up in the environment. Its persistence has been recognised since the 1990s, leading to sustained monitoring interest across its various sources of origin.
With specific reference to the regulation of pesticides, TFA may form in soil following the degradation of specific pesticide active substances, typically those containing a carbon-bonded trifluoromethyl group( CF 3
), and subsequently leach into groundwater or occur as a residue in crops, particularly those grown in rotation with those treated with active substances that degrade into TFA.
The European Food Safety Authority( EFSA) oversees the approval of pesticide active substances in the EU. Approved substances are subject to periodic review to ensure continued compliance with regulatory criteria, considering emerging scientific evidence. Fundamentally, the regulatory framework considers the fate and behaviour of an active
Date |
Details |
TFA was systematically evaluated as a metabolite during the renewal assessment of flurtamone. 1 Toxicological |
Aug-17 |
reference values for TFA were derived from the associated data package. Reference values subsequently utilised |
in renewal assessments of tritosulfuron and flufenacet. |
Flurtamone was not renewed in the EU 2. Non-renewal was based on failure to exclude mutagenic potential of |
Dec-18 |
flurtamone, meaning health-based reference values could not be established and consumer risk assessment could not be finalised. References to TFA mentioned in associated renewal report, however, not a specific factor |
contributing to the non-renewal decision. |
Jan-21 |
New data submitted by Bayer identifying adverse developmental effects of TFA in rabbits as part of REACH dossier submission, triggering follow-up studies to assess human relevance. |
Nov-21 |
The German Environment Agency identified TFA as a persistent and mobile substance with multiple sources contributing to water contamination. 3 |
Aug-23 |
EFSA’ s peer review of tritosulfuron 4 identified multiple unfinalised risk assessments, linked to unresolved TFA data gaps. These included consumer, environmental, ecotoxicological, and aneugenicity concerns. |
Mar-24 |
SCoPAFF agreed that emerging scientific evidence on TFA warranted further consideration to ensure robust and consistent risk assessments across substances. 5 |
June-24 |
CLH dossier submitted by Germany to ECHA, proposing classification of TFA as toxic for reproduction category
1b. 6
|
Jul-24 |
The European Commission formally mandated EFSA to revise toxicological reference values for TFA. 7 |
Oct-24 Tritosulfuron was not renewed in the EU following withdrawal of applicant support. 8 The Danish EPA published the TriFluPest report, demonstrating that extended soil degradation studies
Dec-24 can reveal greater formation of TFA than standard test durations capture. 9 German authorities submitted a CLH proposal to classify TFA as a reproductive toxicant Category 1B, based on
Apr-25 developmental toxicity evidence, including eye malformations. 10 Flufenacet was not renewed in the EU due to endocrine-disrupting properties and the high potential for TFA
May-25 groundwater contamination above legal limits. 11 Authorities confirmed TFA as a toxicologically relevant metabolite under EU guidance. The European Commission issued a joint mandate to EFSA and ECHA to comprehensively assess TFA formation,
Oct-25 fate, behaviour, modelling approaches, and testing methodologies across plant protection and biocidal products. 12 The tenth( most recent) expert Working Group meeting took place as part of the ongoing revision of TFA
Jan-26 toxicological reference values. 13 eport on Flurtamone( August 2017)
Figure 1- Timeline summary of regulatory actions on TFA in the EU
substance and its metabolites in the environment and in crop residues, plus its toxicology to human health and the environment.
Within this context, the significance of TFA as a common metabolite of multiple pesticide active substances has increased over the past decade. It first emerged as a metabolite of interest during the mid-2010s review of the EU approval for the herbicide active substance flurtamone in 2017. In December 2018, the EU declined to renew the approval. Since then, there have been many actions at EU and national level( Figure 1).
Substances at risk
The increasing regulatory attention and scrutiny surrounding TFA and potential precursor pesticide active substances indicate a significant level of uncertainty and risk for certain substances. In this context, it is particularly notable that the EC’ s mandate to review the fate and behaviour of TFA in soil and water explicitly includes, as a core objective of the working group, the identification of such active substances.
The breadth of substances that may fall within this category is considerable. In its background
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