Microbiological quality control of sterilized products

A model describing the dependence of the proportion of items contaminated ( P ) in a population of items on radiation dose ( D ) has been developed. The model was evaluated for a range of doses assuming a Poissonian distribution of micro‐organisms on items prior to and during irradiation and radiation inactivation according to 'multiple‐hit' kinetics; curves relating P and D were constructed. The influence on curve shape of changing the initial average number of micro‐organisms on items and of varying parameters of microbial sensitivity to radiation was assessed. Consideration was given to the value of using sub‐process radiation doses in microbiological quality control testing.