an ethylene oxide vacuum sterilization chamber, having a chamber interior, wherein the ethylene oxide vacuum sterilization chamber is a component of the existing ethylene oxide vacuum sterilizer;

a chlorine dioxide generator, which pneumatically communicates with the chamber interior, wherein the chlorine dioxide generator comprises a source of a chlorine gas and at least one cartridge that is configured to chemically convert the chlorine gas into a chlorine dioxide gas and to inject the chlorine dioxide gas into the chamber interior at a controlled rate corresponding to a selected chlorine dioxide concentration in the chamber interior;

a vacuum pump, which pneumatically communicates with the chamber interior, wherein the vacuum pump is configured to create and control a partial vacuum of a selected sterilization pressure within the chamber interior, and wherein the vacuum pump is configured to effect a controlled post-sterilization evacuation of the chamber interior and to pump an evacuated gas out of the chamber interior;

a steam generator, which pneumatically communicates with the chamber interior through a steam injection port, wherein the steam generator is configured to inject a controlled flow of steam into the chamber interior, as determined by a selected sterilization relative humidity within the chamber interior;

a process control system, comprising multiple sensors configured to monitor multiple process conditions within the chamber interior, wherein the process conditions comprise chlorine dioxide concentration, vacuum pressure, relative humidity, and temperature, and wherein, based on readings of the process conditions by the sensors, the process control system is configured to control the chlorine dioxide generator, the vacuum pump and the steam generator to produce and maintain within the chamber the selected chlorine dioxide concentration, the selected sterilization pressure, the selected sterilization relative humidity, and a selected sterilization temperature, for a selected sterilization duration based on a measured or estimated accumulated chlorine dioxide dosage, and wherein, at the conclusion of the selected sterilization duration, the process control system is configured to control the vacuum pump to evacuate the chamber interior; and

a human-machine interface, which is configured to receive user inputs that specify multiple sterilization process parameters, comprising the selected chlorine dioxide concentration, the selected sterilization pressure, the selected sterilization relative humidity, the selected sterilization temperature, and the selected sterilization duration based on the measured or estimated accumulated chlorine dioxide dosage, wherein the human-machine interface is configured to transmit the sterilization process parameters to the process control system.