Abstract: Chemical waste is burned in oxygen using an electric plasma flame to heat a stream of gas which contains at least 70% by weight oxygen. Liquid waste in fine droplet form is introduced into the gas stream via a two-fluid atomizer using a carrier gas also preferably oxygen. The total amount of oxygen present is at least 30% more than required for complete combustion of the liquid waste. The reaction mixture is maintained at a temperature of at least 1450.degree. C. for a time of at least 2 milliseconds prior to cooling rapidly of the reaction products to a temperature below 300.degree. C.