Ultrashort PFAS in water
In addition to "ordinary longer" PFAS such as PFOS and PFOA, there are also so-called ultrashort PFAS. These are usually characterized by having one to three carbon atoms. Taking the two most common groups of PFAS structures, perfluorocarboxylic and -sulfonic acids, this means that there are five ultra-short compounds; trifluoroacetic acid (TFA), perfluoropropionic acid (PFPrA), trifluoromethanesulfonic acid (TFMS; triflic acid), perfluoroethanesulfonic acid (PFEtS) and perfluoropropanesulfonic acid (PFPrS). These substances can have several sources and occur as degradation products and contaminants or are manufactured for other purposes, e.g. as industrial chemicals. Ultrashort PFAS are receiving more and more attention and a growing number of reports show that they can be found everywhere in the environment, especially in water, including drinking water. TFA has in recent years been given guideline values for drinking water in DK and DE. The compound has also received an RPF factor in the Dutch recommendation for drinking water and should be taken into account in the weighted sum of PFOA equivalents.
In 2023 Eurofins performed a study of Swedish and Norwegian drinking waters. TFA (70-720 ng/l) could be identified in all samples and TFMS in some. TFA could potentially make significant contributions both to the PFAS load in the drinking waters in summations of PFOA equivalents according to RIVM (NL). Read more and download the report here.
During 2024 a number of other reports highlighting the presence of TFA has been published. For example a SGU (Swe Geol survey) report on TFA in Swedish groundwaters, two PAN reports on TFA in EU surface and drinking waters and a publication by the Swe Soc of Nature Conservation on Swedish surface and drinking waters.
Ultrashort PFAS in plants and juice
TFA is not defined as bioaccumulative as such, but can still concentrate in plants, especially above ground and consequently affect vegetable foods. Accumulation factors up to 13000 have been calculated together with mean values of 25-1100 µg/kg DM with occasionally higher values seen (Arp et al, 2024). 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 and apple juice 6 600 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. TFMS was also found but at much lower levels. It can be noted that the formation (and uptake) of TFA may be linked to the degradation of so called “PFAS pesticides” with a CF3-moiety.
Eurofins has introduced, as first major laboratory, analysis of ultrashort PFAS in water. The package code is PLW98 for our 5-pack and PLWB9 for our 7-pack. The corresponding 5-pack for beverages (e.g. juice, beer) is PLWBB. The sample volume required is 2x100 ml or alternatively two consumer packs.