ISO 11137-2:2013

Overview

ISO 11137-2:2013 - “Sterilization of health care products - Radiation - Part 2: Establishing the sterilization dose” specifies validated methods to determine the minimum radiation dose required to achieve a specified sterility requirement. The standard describes procedures to set a product‑specific sterilization dose, to substantiate preselected doses of 25 kGy or 15 kGy for a Sterility Assurance Level (SAL) of 10−6, and to perform routine sterilization dose audits that demonstrate continued effectiveness. It also defines how to group products into product families for dose setting and audit purposes.

Key topics and requirements

• Dose‑setting methods: Uses Methods 1 and 2 (bioburden‑based and fraction‑positive incremental dosing approaches) to predict the dose needed to reach a targeted SAL.
• Dose substantiation (Method VD): Specific procedures to substantiate that a preselected dose (25 kGy or 15 kGy) achieves SAL 10−6 for a product or product family.
• Bioburden and microbiological testing: Requirements for sampling, determination of product bioburden, and interpretation of sterility test results used in dose calculations.
• Sampling and product representation: Definitions and guidance on Sample Item Portions (SIP), selection of representative products, and designation of items that represent a product family for verification experiments.
• Verification dose experiments: Protocols for performing incremental irradiation and sterility testing at sub‑sterilizing doses to extrapolate required sterilization dose.
• Sterilization dose audit: Procedures to routinely audit and confirm that the established dose continues to achieve the required SAL; defines actions on audit failure.
• Product families: Criteria for defining, maintaining and updating product families so that dose setting and audits apply consistently across similar products.

Applications and users

ISO 11137-2 is used by:

• Medical device manufacturers validating radiation sterilization processes
• Sterilization process engineers and validation specialists
• Quality assurance and regulatory affairs teams preparing validation dossiers
• Contract sterilization providers conducting dose setting and routine audits
• Test laboratories performing bioburden and sterility testing

Practical uses include selecting an appropriate sterilization dose, substantiating use of standard doses (25 kGy/15 kGy), designing verification studies, and establishing ongoing audit programs that support regulatory compliance and product safety.

Related standards

• ISO 11137-1: Requirements for development, validation and routine control of a sterilization process
• ISO 11737-1: Determination of a population of microorganisms on products
• ISO 11737-2: Sterility tests used in sterilization validation

Keywords: ISO 11137-2, sterilization dose, radiation sterilization, 25 kGy, 15 kGy, SAL 10^-6, bioburden, dose audit, product family, medical device sterilization.