Beta - Propiolactone Vapor as a Disinfectant 1

Despite recently revived interest in gaseous disinfection or sterilization, only two compounds, formaldehyde and ethylene oxide, have been used to any great extent for this purpose. As discussed by Phillips (1957) in a review of gaseous sterilization, several other compounds have been mentioned in the literature as possessing bactericidal properties in the vapor state but have been put to little, if any, practical application. Formaldehyde had widespread application in the early part of this century for disinfecting sick rooms following occupancy by a person suffering from a contagious disease. It is seldom used for this purpose now, although it still has certain industrial applications as a vapor-phase disinfectant, particularly for large inclosed spaces. Ethylene oxide has come into use only within the last decade. The use of this compound, usually contained in mixtures with carbon dioxide or fluorinated hydrocarbons to reduce its flammability, has permitted the sterilization of many types of materials hitherto considered nonsterilizable because of heat or moisture sensitivity. These materials include plastics, wool, leather, pharmaceuticals, and articles such as notebooks, delicate laboratory equipment, and medical instruments among many others. In general, gaseous disinfection techniques are not proposed to displace other routine standard methods such as steam or chemical solution sterilization, but rather to meet many peculiar problems arising when sensitive materials, for one reason or another, need to be sterilized. Recent activity in gaseous sterilization has been confined largely to the exploitation of new applications of formaldehyde and ethylene oxide, particularly the latter, rather than to a search for additional compounds with different physical or chemical properties. A continuing program of search has been conducted in these laboratories; out of this program f8-propiolactone has emerged as a compound with high biological activity in the vapor state. ,B-Propiolactone more nearly resembles formaldehyde than ethylene oxide in its germicidal properties and possesses a number of advantages over formaldehyde as a gaseous sterilant, particularly with respect to increased antimicrobial activity and lessened per-