Physical and Chemical Monitoring with Reliability Techniques in Sterilizer Management

Abstract

The challenge of a sterilization program is to provide a system which will routinely apply accepted process parameters with minimum deviation. Various techniques which avoid the routine use of biological indicators can be used to monitor the system. The accurate physical measurements of cycle time and temperature may be used to calculate “lethalities,” the consistency of which can be monitored with mean and range control charts. In addition, a “safety analysis” on the possible ways that the sterilizer could fault together with recent information on its mechanical reliability will provide a more comprehensive monitoring protocol. The use of the kinetic model for calculating Nabla values is compared to the F₀ concept and advantages for the method appear to be more precise definition of the response of microorganisms to heating, together with an ability to follow chemical temperature degradation allowing the use of more accurate chemical markers for the monitoring of heat inputs.