The Global Threat from the Irreversible Accumulation of Trifluoroacetic Acid (TFA)

Abstract

Trifluoroacetic acid (TFA) is a persistent and mobile substance that has been increasing in concentration within diverse environmental media, including rain, soils, human serum, plants, plant-based foods, and drinking water. Currently, TFA concentrations are orders of magnitude higher than those of other per- and polyfluoroalkyl substances (PFAS). This accumulation is due to many PFAS having TFA as a transformation product, including several fluorinated gases (F-gases), pesticides, pharmaceuticals, and industrial chemicals, in addition to direct release of industrially produced TFA. Due to TFA's extreme persistence and ongoing emissions, concentrations are increasing irreversibly. What remains less clear are the thresholds where irreversible effects on local or global scales occur. There are indications from mammalian toxicity studies that TFA is toxic to reproduction and that it exhibits liver toxicity. Ecotoxicity data are scarce, with most data being for aquatic systems; fewer data are available for terrestrial plants, where TFA bioaccumulates most readily. Collectively, these trends imply that TFA meets the criteria of a planetary boundary threat for novel entities because of increasing planetary-scale exposure, where potential irreversible disruptive impacts on vital earth system processes could occur. The rational response to this is to instigate binding actions to reduce the emissions of TFA and its many precursors.

Keywords: PFAS; PMT; environmental monitoring; multigenerational exposure; trifluoroacetic acid; vPvM.

Figure 1

Comparison of TFA concentrations detected in different media summarized as before 2010 (green) and after 2010 (in red). Reported values of maximum concentrations found in the literature review are shown as vertical bars and mean values of reported monitoring means and medians are shown with overlapping dots. Numbers indicating the number of summarized individual data points are shown above the corresponding bars. In cases of either green or red bars and dots missing, data were not available for the given media and/or time frame. For air concentrations before 2010 only two studies were available, one of which reported only mean measured concentrations (see Table S1 for the full data set and Figure S3 for air data presented as concentrations from individual studies).