Abstract: A process for the thermal destruction of waste materials of unknown volatility disposed within a container, the process comprising the steps of (a) placing the open container in a combustion chamber of a pyrolysis furnace; (b) providing the pyrolysis furnace with a reducing atmosphere and raising the temperature in the pyrolysis furnace to remove volatile components of the material until a preselected temperature is reached; (c) maintaining the temperature in the pyrolysis furnace while controllably adding air until all the combustible materials are pyrolyzed; (d) continuing to add air during a final oxidation period to achieve combustion of all nonvolatile combustible materials; and (e) processing all volatilized materials in a secondary combustor fluidly communicating with the pyrolysis furnace.