Studies on the Dose Requirement for the Radiation Sterilization of Medical Equipment. I. Influence of Suspending Media

Abstract

S ummary : Spores of Bacillus pumilus were air dried from various suspending media on to the surfaces of different materials representative of those used for medical equipment currently being radiation‐sterilized on a commercial scale. The resistance of the spores to gamma radiation was measured (inactivation factor of 10 15 at 2·5 Mrads) and compared with that of the spores in liquid suspension under both aerated and anoxic conditions. Neither the nature of the medium nor that of the supporting surface affected radiation resistance except where local anoxic conditions might be expected, i.e. with spores suspended in a grease and with those trapped in a soluble film surface, when a twofold increase was observed.