The Effects of Trifluoroacetic Acid (TFA) in Humans: A Rapid Review

Abstract

Human studies involving exposure to trifluoroacetic acid (TFA) and the associated clinical outcomes are typically not considered in standard chemical toxicity assessments. This review aimed to identify and synthesize all available human data on TFA exposure, regardless of study design or context. Given TFA's long-standing use and its formation as a degradation product of various compounds, a wide range of exposure scenarios was considered, including post-anesthesia monitoring, environmental assessments, and chemical incidents. The database searches in MEDLINE (PubMed) and EMBASE (Scopus) were conducted on 28 and 29 April 2025. A total of 17 studies met the inclusion criteria: 4 case reports, 3 case series, 5 observational studies, and 5 pharmacokinetic studies. All studies documented clear human exposure to TFA and reported at least one TFA-related outcome. Some acute exposures exceeded the currently proposed threshold values. However, no study demonstrated clinically relevant effects attributable to TFA. As a strong acid, TFA can cause typical corrosive injuries upon direct contact, but no additional systemic or organ-specific toxic effects were observed.

Keywords: PFAS; TFA; halothane; human; toxicity; trifluoroacetic acid.

Figure 1

Search results, study selection, and inclusion process [8].

Figure 2

Total TFA exposure in halothane-related studies in (1) a most probable and (2) a worst-case scenario. The weighted mean + standard deviation of the TFA-exposure over the whole study duration, either from inhalation of air containing halothane in operating rooms or through halothane anesthesia, is shown. The weighted means were calculated based on the mean TFA exposures of each study, taking into account the number of participants for each study. The dotted line represents the Acute Reference Dose (ARfD) of 0.6 mg/kg body weight proposed by EFSA in its draft statement on consumer health-based guidance values on TFA [5].