The spore population on the Certificate of Analysis is reported as the heat shocked population per unit (biological indicator) with the exception of spore suspensions which are reported per 0.1 mL. Each product has a specific recommended population assay method. Population procedures are located on each product page.


Process Challenge Devices (PCDs) are used in routine production sterilization cycles as an external test pack. They are designed to help medical device manufacturers and contract sterilization providers efficiently and accurately confirm EO sterility assurance. PCD patented products nominally consist of any commercial Biological Indicator strip, disc or Self-Contained BI (SCBI) in a proprietary EO barrier pouch. Directions for use can be found here.

Please refer to ISO11135 and EN550 for regulatory guidance.