Sterilization methods and apparatus are effective to achieve a 6-log
reduction in CFUs of industry standard bacteria and bacterial spores,
i.e., B. stearothermophilus and B. subtilis spores, by subjecting
sterilizable materials to a chemical additive-containing carbon dioxide
sterilant fluid at or near its supercritical pressure and temperature
conditions. Most preferably, the chemical additive-containing
supercritical carbon dioxide sterilant fluid is agitated during
sterilization, e.g., via mechanical agitation or via pressure cycling.