INTRODUCTION

A biological indicator (BI) is a well-characterized preparation of a specific microorganism that has known resistance to a specific sterilization process. BIs are used to demonstrate the effectiveness of processes that render a product sterile in its final package or container, as well as the effectiveness of the sterilization of equipment, product contact materials, and packaging components as required. BIs may also be used to monitor established sterilization cycles and are used for periodic reassessment of sterilization process effectiveness. BIs are process aids and can support the correlation of physical parameters to microbiological destruction. Microorganisms recognized as suitable for BIs are spore-forming bacteria; the spores of these microorganisms are significantly more resistant than the vegetative cells that comprise the majority of bioburden in or on materials.