Accumulation of TFA (trifluoroacetic acid) in the environment
TFA is a compound that has received wide attention over the last few years. More or less all recent studies point to the fact that it is present on a global scale and found in all environmental (e.g. water, soil sediment, plants) and human matrices (e.g. blood). Moreover, there are numerous sources and concentrations are increasing rapidly, in relative terms. A new review article by Arp et al. in the journal EST (Env Sci & Tech, in press), highlights the irreversibility of this accumulation since TFA is not known to degrade to any large extent. The authors also argue that there is not enough (eco)toxicological data to tell, overall, at which level the threshold for serious adverse effects lies.
According to the most recent OECD definition (2021), TFA is considered as a PFAS, since it has a fully fluorinated methyl group. The substance is therefore included in the group of so called ultrashort PFAS (≤3 carbons). Concerning sources, phototransformation of the refrigerants HFC-134a, HFO-1234yf and likely other HFC/HCFC is, taken as a whole, probably the largest contributing process. However, TFA may also be formed at degradation of pharmaceuticals and pesticides (e.g. Fluazinam) having trifluoromethyl moieties. Thus there is a link between TFA and the concept of “PFAS pesticides”. Furthermore, combustion of F-polymers and the use of TFA as reagent in different organic syntheses alongside direct industrial releases are all possible sources.
Concentrations in plants and water
TFA is not defined as bioaccumulative as such, but can still concentrate in plants, especially above ground and consequently affect vegetable foods. In the article, accumulation factors up to 13000 are cited together with a concentration range (averages) between 25-1100 µg/kg DM with occasionally higher values recorded. Studies of drinking water since 2010 show a mean concentration of ~600 ng/l with some individual samples exceeding the Dutch guideline value of 2200 ng/l.
Eurofins has in 2023-24 published two reports on ultrashort PFAS (incl TFA) and made analytical contributions to a new study by the Swedish Society of Nature Conservation (SSNC). The Eurofins drinking water report for 32 cities in Sweden and Norway showed a TFA range between 70-720 ng/l and a mean of 280 ng/l. The SSNC study, covering 63 drinking waters gave a similar picture with levels up to 870 ng/l. In Eurofins’ work together with Örebro University (SE), it was found that TFA in orange juice on average had a concentration of 34 000 ng/l, when detected, most likely a result of accumulation in the fruits. TFA was observed in 12 out of 14 conventional products and in one of seven organic.
PFAS determination
Eurofins can offer a wide range of PFAS analysis in different matrices. Also ultrashort PFAS, including TFA, can be determined. Search our online catalogue or contact us for more information. Regarding our own studies on ultrashort PFAS incl our white paper on juice, see our publication page.
Links
EST review (in press; open access)
SSNC report
Eurofins publications
Eurofins search engine