Abstract. We have investigated trifluoroacetic acid (TFA) formation from emissions of
HFO-1234yf (CF3CFH2), its dry and wet deposition, and rainwater concentration over
India, China, and the Middle East with GEOS-Chem and WRF-Chem models. We
estimated the TFA deposition and rainwater concentrations between 2020 and
2040 for four previously published HFO-1234yf emission scenarios to bound
the possible levels of TFA. We evaluated the capability of GEOS-Chem to
capture the wet deposition process by comparing calculated sulfate in
rainwater with observations. Our calculated TFA amounts over the USA,
Europe, and China were comparable to those previously reported when
normalized to the same emission. A significant proportion of TFA was found
to be deposited outside the emission regions. The mean and the extremes of
TFA rainwater concentrations calculated for the four emission scenarios from GEOS-Chem and WRF-Chem were orders of magnitude below the no observable effect concentration. The ecological and human health impacts now, and the continued use of HFO-1234yf in India, China, and the Middle East, are estimated to be insignificant based on the current understanding, as summarized by Neale et al. (2021).
Supplementary material to "Trifluoroacetic acid deposition from emissions of HFO-1234yf in India, China and the Middle East"