Sterilization Education

Understand ISO 11137 in <5 minutes

Looking for a basic overview of the standard for radiation sterilization? We have you covered.

ISO 11137 is an international standard that deals with the sterilization of healthcare products, particularly focusing on the use of radiation. It consists of multiple parts, each addressing different aspects of the sterilization process using irradiation. 

Note that it is generalized across radiation sterilization modalities: Gamma, E-Beam, and now X-ray as well.

Summary of 11137’s main parts:

  • ISO 11137-1 (last rev 2006): Requirements for development, validation, and routine control of a sterilization process for medical devices:
    • This part is an overview: it outlines the requirements for the development, validation, and routine control of a sterilization process using radiation.
    • It includes detailed guidance on selecting the appropriate dose for sterilization, how to validate the process, and how to maintain process control to ensure the continuous effectiveness and safety of the sterilized products.
  • ISO 11137-2 (last rev 2013): Establishing the sterilization dose:
    • Part 2 focuses on methods to establish the appropriate sterilization dose. 
    • It provides detailed instructions on performing dose audits and using bioburden data (the count of bacteria or other microorganisms on a product) to determine the minimum radiation dose needed to achieve sterility.
  • ISO 11137-3 (last rev 2017): Guidance on dosimetric aspects:
    • This section offers guidance on dosimetric aspects of the radiation process.
    • It covers the calibration and standardization of dosimetry equipment, the methods for determining the dose received by a product during irradiation, and ensuring that the dose is uniformly applied to achieve effective sterilization.
  • ISO 11137-4 (first rev 2020): Guidance on process control
    • Section provides additional guidance to that given in ISO 11137-3 on meeting the requirements specified in ISO 11137-1, ISO 11137-2 for the establishment and process control of a radiation sterilization process using different radiation modalities.


These parts collectively help manufacturers of medical devices to implement a radiation sterilization process that is compliant and consistent with international safety and quality standards, ensuring that medical devices are free of viable microorganisms when they reach the end-user.