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19 July 2008

Answer to Question #756 Submitted to "Ask the Experts"

Category: Industrial Radiation — Industrial Applications

The following question was answered by an expert in the appropriate field:

Where can I find information about gamma radiation sterilization? I'm working in validation process. I need information about vascular prosthesis sterilization. Thanks.

In order to meet international requirements for validation of sterilization of any medical device, including prostheses, manufacturers must comply with the International Organization for Standardization (ISO) 11137 - Sterilization of Healthcare Products - Requirements for Validation and Routine Control - Radiation Sterilization. This standard provides requirements and guidance in qualifying product for radiation sterilization and validating the sterilization process for electron beam, x-ray, ⁶⁰Co, and ¹³⁷Cs irradiators. It is also an Association for the Advancement of Medical Instrumentation (AAMI) Standard. The accepted definition of "Sterile" is the absence of viable organisms. Since biological response to many killing agents (including radiation) is log/linear this is a mathematical impossibility. Therefore it is important to be aware of jurisdictional requirements for using the "Sterile" label. I refer you to EN 556, the Européen Normalisation Standard and AAMI ST67 (US). You should be aware of work in progress by the national organizations in cooperation with ISO to further develop 11137. The result is expected to be four parts:

11137-1 Requirements for the development, validation, and routine control of a sterilization process for medical devices
11137-2 Dose setting methods
11137-3 Dose substantiation of 25 kGy
11137-4 Dosimetry, dose mapping, and routine monitoring

As well, if you are manufacturing in the United States or for the U.S. market and your product will cross state or national borders, you must comply with the Food and Drug Administration's (FDAs) Good Manufacturing Practices (GMP). A great deal of assistance in complying with the GMPs may be obtained from the FDA's Centre for Devices and Radiological Health, Division of Small Manufacturers. I hope this helps. Establishing that production materials are routinely and reproducibly sterilized with a high degree of confidence is not a trivial undertaking and, of course, is an important health issue. However, radiation is one of the simplest and most efficacious means of sterilization.

John Barnard
Director of Facilities Acsion Industries Incorporated

Answer posted on 16 March 2001. The information and material posted on this Web site is intended as general reference information only. Specific facts and circumstances may alter the concepts and applications of materials and information described herein. The information provided is not a substitute for professional advice and should not be relied upon in the absence of such professional advice specific to whatever facts and circumstances are presented in any given situation. Answers are correct at the time they are posted on the Web site. Be advised that over time, some requirements could change, new data could be made available, or Internet links could change. For answers that have been posted for several months or longer, please check the current status of the posted information prior to using the responses for specific applications.