Abstract: Halogenated hydrocarbon waste materials are burned in a horizontal fire tube boiler. In the disclosed and illustrated embodiments, liquid and/or gaseous waste of highly chlorinated hydrocarbons (often, very inert content) are input along with a flow of fuel oil or gas as required to increase combustion temperature. While high combustion temperatures are achieved, a stable flame front is established. A refractory lined combustion chamber of substantial length is incorporated to contain the flame front near adiabatic conditions for sufficient dwell time so that the combustion gases leaving the vicinity achieve near complete combustion. Before entering the water jacket boiler furnace tube the temperature of the flue gas is dropped to a level enabling the use of standard materials of construction of the tube sheets of the boiler, where the fire tube boiler is most vulnerable to corrosion from excessive temperatures and condensation of chlorinated hydrocarbons reacting on the interior thereof.