Liquid spray curtains can be used to contain the effect of accidental release of toxic gases; they work by a combination of dilution and absorption. In this work, we have investigated the possibility of adding chemicals to the liquid spray which may react with the toxic gases and enhance the absorption capacity of the spray. The work is aimed at a fundamental understanding of the chemistry and the mass transfer behavior of toxic gas --reactive liquid systems. We have performed continuous mass transfer rate experiments on one sphere absorber (the model systems considered being CO2/Na2CO 3 and O2/Na2SO3), and we have interpreted these in terms of mass transfer with chemical reaction theory. The system was modelled as a series of a sphere gas-liquid reactor (SGLR) and a continuous-stirred tank (CST). A numerical technique was used to predict both the unsteady state liquid reactant concentration and the specific absorption rate of gas in the system. A systemic approach was employed to determine values of key parameters that quantify a given mechanism. The results obtained, together with pilot plant results on the hydrodynamics of liquid sprays, may form the basis for a predictive model of chemical liquid spray behavior in environmental control.