25 February 2021

The Environmental effects assessment panel comprehensive summary of Trifluoroacetic acid (TFA) effects [1] states that humans could be exposed to TFA via drinking water and food but there is no evidence to date of adverse effects on health. Recently the Federal Environment Agency UBA issued a revised guidance value for TFA in drinking water [2], based on improved toxicological studies availability for trifluoroacetate salts. This sets a drinking water health guidance value of 60 μg/L and a target value of 10 μg/L. The UBA was able to set a toxicologically justified LWTW for drinking water. The LWTW of 60 µg/L is based on the life-long tolerable daily intake of TFA via the drinking water (assumption: 2 L per day), in which no harm to human health is to be expected. This guideline replaces the health orientation value (GOW) of 3 µg/l (maximum values that apply if the toxicological data is incomplete).

Relevant background information:
[1] From the EEAP summary, analysis of 1187 samples of rainwater collected in eight locations across Germany in 2018–2019 showed median and a precipitation-weighted mean concentration of TFA of 0.210 μg/L and 0.335 μg/L, respectively. The maximum measured concentration was 57 μg/L. [3] The study on Future emissions and atmospheric fate of HFC-1234yf from mobile air conditioners in Europe assessed the future emissions of HFO-1234yf after a complete conversion of the European vehicle fleet and calculated that the use of HFO-1234yf would result in expected average values of 0.6 – 0.8 µg/L of TFA in European rainwater.
[1] Neale, R. E., Barnes, P. W., Robson, T. M., Neale, P. J., Williamson, C. E., Zepp, R. G., et al. (2021). Environmental effects of stratospheric ozone depletion, UV radiation, and interactions with climate change: UNEP Environmental Effects Assessment Panel, Update 2020. Photochemical & Photobiological Sciences. See sections 7.8 to 7.11 for Trifluoroacetic acid (TFA). See also the item in this newsletter
[2] Trifluoressigsäure (TFA)–Gewässerschutz im Spannungsfeld von toxikologischem Leitwert, Trinkwasserhygiene und Eintragsminimierung. Erläuterungen zur Einordnung des neuen Trinkwasserleitwerts von 60 μg/L.
20. Oktober 2020. Umweltbundesamt
[3] Stephan Henne, Dudley E. Shallcross, Stefan Reimann, Ping Xiao, Dominik Brunner, Simon O’Doherty, and Brigitte Buchmann, Future Emissions and Atmospheric Fate of HFC-1234yf from Mobile Air Conditioners in Europe, Environ. Sci. Technol., 2012, 46 (3), pp 1650–1658 DOI: 10.1021/es2034608.