Steam Sterilization

Manufacturers of Reusable Medical Devices designed to be sterilized by steam must provide detailed instructions for reprocessing. The manufacturer shall validate that the instructions provided are capable of sterilizing the medical device for its intended use. The validated packaging configuration as well as steam sterilization parameters must be provided to the health care facilities in these instructions.

The most common steam sterilization cycles used in the industry are the gravity-displacement and dynamic-air-removal. In gravity-displacement the steam enters the sterilizer chamber and displaces the residual air through an open vent. A more efficient cycle type is the dynamic-air-removal, specifically the prevacuum cycle, in which the air is removed from the chamber and load by means of pressure and vacuum excursions. Flash sterilization cycles consist of higher temperatures for a shorter time and are designed for processing patient care items for immediate use. At Pacific BioLabs the overkill sterilization model is used with these two cycle types to demonstrate a 10-6 Sterlity Assurance Level (SAL) when performing a steam sterilization validation. For more information see ANSI/AAMI ST79:2006 Comprehensive guide to steam sterilization and sterility assurance in health care facilities.

The following are the most common steam sterilization cycles validated at PBL:

Additionally, the following table lists minimum cycle times for gravity-displacement steam sterilization cycles:

For dynamic-air-removal steam sterilization cycles, the following table lists minimum cycle times: