ST79 Testing – Gibraltar Labs Inc.
ST79 Testing is described in ANSI/AAMI ST79, Comprehensive Guide to Steam Sterilization and Sterility Assurance in Health Care Facilities. Manufacturers of medical device trays, instruments and rigid containers are responsible to demonstrate that these items can be cleaned and steam sterilized.
ST79 testing is performed at Gibraltar Laboratories to ensure that patients will be safe. The manufacturer writes a ST79 testing protocol that is purposely designed to be very challenging to pass. Gibraltar performs ST79 testing and writes a validation report. The validation report is submitted to the FDA by the manufacturer. The manufacturer prepares for the end users instructions for use based on the successful ST79 testing.
A typical protocol for ST79 testing is written to simulate worst case conditions. Specifically,  relatively resistant bacterial spores are inserted into the instrument at locations judged to be most recalcitrant to penetration by steam,  half the anticipated sterilization exposure time is used to determine spore death and  maximum and minimum loads are separately sterilized. It is not well known whether moist heat sterilization is more readily achieved under maximum or minimum load configurations. In our studies we have observed that minimum load conditions can be more difficult to achieve sterilization then maximum load conditions. We have published two papers that describe examples of how ST79 testing demonstrated that the minimum load condition was more stringent than the maximum load moist heat steam sterilization condition. For more information please refer to two publications.
The papers are available on our website https://www.gibraltarlabsinc.com/
To learn more about ST79 Testing from Gibraltar Labs, please call us at (973) 227-6882 or submit a contact form by clicking here.