There’s a lot of activity right now for the sterilization of medical devices and we’re starting off our reviews of these publications with the AAMI TIR56. This new release, “Guidance for the development, validation and routine control of an ethylene oxide sterilization process utilizing flexible bag systems for the sterilization of medical devices,” is a first edition. It provides a methodology for ethylene oxide sterilization that differs from the ISO 11135 (new edition just released as well).
This new AAMI guidance document is a response to the July 2014 update of the ISO 11135. That’s because the new ISO edition does not cover sterilization by injecting EO directly into individual product packages or a flexible chamber. So the TIR56 (Technical Information Report) provides immediate guidance while specific issues continue to be worked out at the international level.
Methods in the new TIR56 use processes based only on gas injection by weight, variable, or diminishing ethylene oxide (EO) concentrations. These concentrations are measured in the atmosphere external to the package but internal to the flexible bag sterilization system that’s part of the design of the method.
You’ll also find that the approaches to validation, routine monitoring, and control of cycles may differ significantly from the ISO 11135 as well. A number of special equipment designs used to remove EO from the flexible sterilization bag are also different from the ISO standard. This means that there’s also a different set of ways to identify worst-case aeration processes and subsequent validation.
Another difference is that for some process designs, the effectiveness of the sterilization is based on storage conditions and time. Or sterilization provided during the storage period within the sterilization/aeration cabinets may also act simultaneously in providing the aeration method.
The introduction notes that there are still some open issues in the use of EO sterilization in flexible packaging. One centers on the safety in the workplace issues surrounding the use of EO. You’ll have to look to other resources to address this problem. Another deals with the lack of documentation on the efficacy or repeatability of EO use in this application. The committee that developed the TIR expects that as the process is used, more information on this topic will be generated.
You can purchase your copy of the AAMI TIR56 from Document Center Inc., an authorized dealer of the AAMI standards. It is available at our webstore www.document-center.com either in paper format or for pdf download. Should you need additional information or assistance, please contact our staff by phone (650-591-7600), fax (650-591-7617) or email (info@document-center.com). We have over 30 years experience in the standards business. Make us your Standards Experts!
