Coefficients for the volatilization from water of 1,1,1-trichloroethane and 1,2-dichloroethane were measured in a stirred tank. Experiments at constant mixing conditions over a wide range of concentrations showed that the volatilization coefficient was independent of concentration, confirming the assumption that volatilization is a first order process. Simultaneous measurements of the volatilization coefficient and the oxygen absorption coefficient over a wide range of mixing conditions showed that the chlorinated hydrocarbon/oxygen coefficient ratios for both compounds were independent of mixing conditions. Ratios of 0.596 and 0.621 were obtained for 1,1,1-trichloroethane and 1,2-dichloroethane, respectively.