Trifluoroacetic Acid: Toxicity, Sources, Sinks and Future Prospects

Abstract

Trifluoroacetic acid (TFA) is a known and persistent pollutant in the environment. Although several direct anthropogenic sources exist, production from the atmospheric degradation of fluorocarbons such as some hydrofluorocarbons (HFCs) has been a known source for some time. The current transition from HFCs to HFOs (hydrofluoroolefins) is beneficial from a global warming viewpoint because HFOs are much shorter-lived and pose a much smaller threat in terms of warming, but the fraction of HFOs converted into TFA is higher than seen for the corresponding HFCs and the region in which TFA is produced is close to the source. Therefore, it is timely to review the role of TFA in the Earth’s environment. This review considers its toxicity, sources and removal processes, measurement in a variety of environments, and future prospects. New global model integrations are used to quantify the impacts of uncertainties on TFA levels using the Henry’s Law constant for TFA and the range of gas-phase kinetic parameters chosen for the reaction of OH radicals with a representative HFO (HFO-1234yf). Model runs suggest that TFA surface concentrations vary by up to 10% based on Henry’s Law data but could be up to 25% smaller than previously modelled values suggest depending on the kinetic analysis adopted. Therefore, future estimates of TFA surface concentrations based on HFO removal require updating and the kinetic analysis of TFA production warrants further investigation. The toxicity of TFA appears to be low, but further studies of a much wider range of animal and plant types are required.

Perspective on Theoretical and Experimental Advances in Atmospheric Photochemistry

“…Unintended consequences of HFO use may be significant production of HFC-23 (a long-lived and potent greenhouse gas) and trifluoroacetic acid (TFA), which is a persistent environmental pollutant. 60,221 3.6. Aerosols.…”

“…Important examples discussed at the CECAM workshop include the photochemical oxidation pathways of HFOs, which are planned replacements for hydrofluorocarbons (HFCs) now recognized as significant greenhouse gases. Unintended consequences of HFO use may be significant production of HFC-23 (a long-lived and potent greenhouse gas) and trifluoroacetic acid (TFA), which is a persistent environmental pollutant. , …”

The global threat from the irreversible accumulation of trifluoroacetic acid (TFA)

“…There has been increasing debate since the 1990s about the hazard-related concerns of TFA and other short-chain PFAAs, which have been considered comparatively less bioaccumulative and toxic than PFAAs with longer perfluoroalkyl chains 8,9,[16][17][18][19][20][21][22][23] . However, these early reports did not consider TFA's ubiquitous accumulation in the exposome, in https://doi.org/10.26434/chemrxiv-2024-0djqt ORCID: https://orcid.org/0000-0002-0747-8838 Content not peer-reviewed by ChemRxiv.…”

Advancing Sustainable Peptide Synthesis by Solvent Quality Control: Understanding and Mitigating Hydroperoxide in 1-Butyl-2-pyrrolidinone (NBP)

“…Minimizing waste has been tackled by a variety of approaches as well, including adopting principles of circular economy, ,,,, minimizing solvent washing, and using organocatalysis as well as side chain-unprotected AAs . Still, while ample work in the context of sustainable SPPS remains, not least in expanding its scope and eliminating the highly corrosive PFAS chemical TFA, which is the universal resin cleavage reagent, based on the above delineated studies it is nonetheless apparent that SPPS has the potential to become not only the most versatile peptide synthesis method but also one that is truly sustainable. Therefore, while addressing sustainability challenges in the peptide synthesis field will require further developments in the emerging alternative peptide synthesis platforms, it can nonetheless be anticipated that SPPS will continue to play a major role in the production of peptides from the lab to the plant as well, in which sense advancing sustainable SPPS methods will be invaluable.…”