An introduction system for introducing an atmosphere into an interior of an autoclave alters an existing atmosphere. The introduction system comprises at least one source of actuating gas; an actuating mechanism, a pressure barrier that separates an interior of the autoclave from ambient exterior atmosphere; and a containment vessel that is located at least partially in the interior of the autoclave. The containment vessel comprises a plurality of walls, at least one of the walls comprising a release wall structure of the containment vessel, a vapor producing material cavity, where the walls define the vapor producing material cavity; and an opening element. The opening element is movable by the opening actuator device. The release wall structure of the containment vessel is rapidly opened by the opening element to effect a rapid release of vapor producing material in the vapor producing material cavity into the interior of the autoclave. The autoclave is provided with at least an increased pressure, so a rapid release of vapor producing material in the vapor producing material cavity into the interior of the autoclave causes the vapor producing material to vaporize into a vapor, thus altering an atmosphere in the autoclave. The actuating mechanism comprises an opening actuator device. The at least one source of actuating gas in communication with the opening actuator device and flow from the at least one source of actuating gas is controlled by a control device.