Evaporation rates of H₂O and HCl were observed from a thin film condensate at low temperature at an average HCl mole fraction of 10(−5)–10(−3) in order to probe the evaporative lifetime of ice particles of the upper troposphere and lower stratosphere. The results show a decrease in the H₂O evaporation rate with increasing mass loss of the condensate under conditions where the saturation vapor pressure corresponded to pure ice. This supports gas–surface reactions of HCl-doped ice particles.