Trifluoroacetic Acid (TFA) in Agricultural Runoff: New Study from NIBIO
TFA is a persistent and highly mobile ultrashort-chain PFAS compound increasingly detected in environmental matrices, including water and food systems. In agricultural contexts, a major source of TFA can be the degradation of “PFAS pesticides” with C-CF₃ groups, highlighting a potential link between the use of these products and diffuse contamination in agroecosystems. A new report from NIBIO (Norwegian Institute of Bioeconomy Research) presents monitoring results from the agricultural Skuterud catchment in Norway (449 ha) for 2025–2026, demonstrating that TFA concentrations in stream water ranged from 470 to 2200 ng/L, with a mean of ~1080 ng/L. Annual TFA leaching was estimated at 3.3 kg, with the majority of transport occurring during high-flow events in autumn and strongly correlated with nitrate leaching. Source apportionment indicates that more than 70–80% of TFA originated from degradation of C-CF₃-based pesticides such as fluopyram and trifloxystrobin, while atmospheric deposition contributed a smaller fraction (~20%). Analytical determination of TFA and other ultrashort PFAS was performed by Eurofins.
Processes and Research Needs
The study shows that TFA behaves similarly to nitrate with leaching dominated by drainage systems and triggered by excess precipitation, reflecting its high solubility and limited sorption to soils. Seasonal dynamics were evident, with accumulation of TFA in soil pore water during summer followed by rapid leaching during autumn rainfall. At the same time minor contributions from sewage sludge, manure, and other PFAS precursors remain uncertain. Additionally, trace levels of other ultrashort PFAS (PFPrA and TFMS) were occasionally detected. The findings strongly suggest that agricultural practices, particularly the use of PFAS-related pesticides, are a dominant driver of TFA emissions in intensively managed catchments. The leaching of TFA showed good agreement with TFA equivalents in applied C-CF3 pesticides with an average of 3.8 kg per year. The authors identify knowledge gaps regarding the spatial distribution of TFA in soils and crops, long-term accumulation, and the relative importance of secondary sources such as sludge and atmospheric inputs. The report highlights a need for further research, including systematic sampling of soil–plant systems, improved monitoring of precipitation inputs, and investigation of transformation pathways and environmental fate.
NIBIO TFA report (in Norwegian)
