Abstract: A method and control apparatus for the safe and effective ultimate disposal of spent biocidal gases such as alkylene oxides after their use in a reactor, including hopsital-type gaseous sterilizers, to reduce the concentration of viable organisms present as contaminants in articles treated in the reactor. The disposal is carried out in a manner to prevent air contaminating release of objectionable material into the atmosphere. The process includes the steps of pumping the biocidal gas from the reactor, delivering the gas to a combustion chamber fitted with a flue gas stack, and igniting and burning the gas in the combustion chamber in the presence of and aided by an added auxiliary combustible fuel augmented by a supply of air. Safety devices such as temperature controls and sensors, flame sensors, flash arrestors, and automatic shut off valves minimize potential hazards.