Trifluoroacetic Acid (TFA) in the Environment: Occurrence, Persistence, and Treatment

ABSTRACT Trifluoroacetic acid (TFA) is an ultrashort‐chain perfluoroalkyl acid characterized by high mobility, environmental persistence, and resistance to conventional treatment and natural attenuation. It is widely detected in precipitation, surface water, groundwater, and drinking water, and often dominates per‐ and polyfluoroalkyl substances (PFAS) profiles in aqueous systems. This study synthesizes available data on TFA occurrence, toxicity, and treatment to evaluate its environmental behavior and management challenges. Toxicity data indicate low intrinsic toxicity across aquatic, terrestrial, and mammalian systems, with effects observed at concentrations well above typical environmental levels. Interpretation remains limited by variability in analytical methods and gaps in long‐term and cross‐species data. Treatment technologies developed for legacy PFAS are largely ineffective for TFA. Sorption‐ and interfacial‐based processes provide negligible removal, while separation processes, such as reverse osmosis, concentrate TFA into residual streams. Many oxidative, electrochemical, and plasma‐based systems do not achieve mineralization and may generate TFA as a terminal product. Only a limited number of technologies demonstrate defluorination under controlled conditions, with hydrothermal alkaline treatment (referred to as HALT) among the few approaches achieving complete defluorination. Overall, TFA represents a practical limitation of current PFAS management strategies, with persistence through treatment systems likely leading to increasing dominance in treated waters and expansion of diffuse plumes.