EEAP 2022: Human and environmental risks associated with TFA in the environment

Risks from exposure to TFA in terrestrial animals: EEAP 2022 described a report on the potential effects of TFA in mammals. “This was a report on the effects of exposure to TFA salts via drinking water in male laboratory rats. The tests followed OECD guidelines (Tests 417 and 452) and exposures were for 90, 370, and 412 days at concentrations in the drinking water of 0 (control), 30, 120, and 600 mg TFA acid equivalent/L. The latter concentration was equivalent to a daily intake of 37.8 mg TFA/kg (body mass). Responses measured were activity of the enzymes alanine-amino-transferase (ALT) and glutamate-pyruvate-transferase (GPT) in the blood. No significant effects were observed at 30 mg/L for any time of exposure but a significant increase in ALT activity was observed at 120 and 600 mg TFA acid equivalent/L at 370 days but not at 412 days. No effects on GPT were reported. In a second study with exposures for 14, 28, and 90 days to 0, 600, 1200, and 2400 mg TFA acid equivalent/L, no significant effects on ALT were observed. Increases in the activity of enzymes in or originating from the liver are considered as compensatory unless accompanied by physiological responses such as loss of weight. This reported effect does not change the conclusion that TFA is of low toxicity in mammals.”

“An extensive review of the potential effects of TFA in the environment published by the German Environmental Agency [1] did not identify any risks other than the persistence of TFA in the environment, which is a legislative rather than toxicological criterion. The concentrations of TFA in beer and tea discussed above are small when compared to the NOED of TFA in mammals. This indicates that the risk to humans from residues of TFA in beer and tea are de minimis (of little importance).”

Risks of exposure to TFA in aquatic organisms: EEAP 2022 reported one new toxicity test for an aquatic organism. This was a retest of the most sensitive alga (Raphidocelis subcapitata).  The study protocol followed OECD guideline 201. Effect values were based on growth. A no observed effect concentration (NOEC) of 2.5 mg acid equivalent/L (2,500,000 ng/L) was reported based on inhibition of growth. The detailed report of the study was reviewed by ECHA and was classified as “reliable without restriction”, hence it has been used here in the characterisation of the toxicity of TFA to aquatic organisms.

“The margin of exposure between the distribution of no observed effect concentrations (NOEC) of trifluoroacetic acid salt from a range of studies and the observed and expected concentrations in the oceans and endorheic basins is several orders of magnitude and is indicative of de minimis risk.”

References

[1] UBA. (2021). Persistent Degradation Products of Halogenated Refrigerants and Blowing Agents in the Environment: Type, Environmental Concentrations, and Fate with Particular Regard to New Halogenated Substitutes with Low Global Warming Potential. Vol. FB000452/ENG. Umwelt Bundesamt, Dessau-Roßlau.