The evaporation path for emulsions of phenethyl alcohol stabilized by a non-ionic surfactant, Laureth 4, a commercial ethoxy adduct, approximately C-12(EO)(4), was estimated by calculations using the phase diagram. The results for emulsions with an O/W ratio equal to or greater than 1/3 showed the relative humidity only in excess of 90% to have a significant effect on the evaporation path. In fact the path was not significantly modified for relative humidities from 0% to 90%, but in the range 90-100% the modification of the evaporation path was most pronounced; not only altering the path, but causing entirely different phases to appear in the emulsion. On the other hand, for emulsions with lower O/W ratios these effects were substantial for relative humidities down to the level of 40%. (C) 2009 Elsevier Inc. All rights reserved.