Various gas sterilization methods have been investigated in the past. Methods using ethylene oxide and other disinfecting gases are widely used for sterilizing a wide range of medical products from pharmaceutical preparations to surgical instruments. Irradiation alone or together with disinfecting gases has also been investigated, as summarized by Russell, A., The Destruction of Bacterial Spores, New York: Academic Press (1982).
A sterilizing method must effectively render all microbial organisms non-viable without damage to the article or goods being sterilized and its packaging. However, many disinfecting gases which meet this criteria, such as ethylene oxide and irradiation methods, have been recognized to expose workers and the environment to safety hazards. Recent legislation has been severely restricting the amount of hazardous gases such as ethylene oxide (a suspected carcinogen) in the working environment, or the use of any system or method which produces toxic residues or exhaust products. This has been presenting a major crisis in hospitals and other areas of the health industry.