- ISO 11135 is an international standard that specifies requirements for the development, validation, and routine control of ethylene oxide (EO) sterilization processes for medical devices. This standard is crucial for manufacturers and healthcare facilities that use ethylene oxide sterilization to ensure the safety and sterility of medical devices.
- The standard provides a comprehensive framework for establishing and maintaining an effective sterilization process using ethylene oxide. It covers all aspects of the sterilization process, including equipment qualification, process definition, validation, and routine monitoring. The requirements ensure that the sterilization process is both effective in achieving the desired sterility assurance level (SAL) and safe for the end-users of the sterilized devices.
- Process definition and development under ISO 11135 requires careful consideration of various parameters that affect sterilization efficacy. These include gas concentration, temperature, humidity, exposure time, and pressure. The standard emphasizes the importance of understanding how these parameters interact and their impact on sterilization effectiveness while maintaining product functionality and safety.
- Validation requirements form a significant portion of the standard, comprising three main elements: installation qualification (IQ), operational qualification (OQ), and performance qualification (PQ). IQ ensures that equipment and systems are properly installed and documented. OQ demonstrates that the equipment operates within established limits when used according to procedures. PQ confirms that the process consistently produces acceptable results under normal operating conditions.
- The standard places significant emphasis on microbiological aspects, including the determination of bioburden (the number and types of viable microorganisms present on or in a product before sterilization) and the establishment of an appropriate sterility assurance level. This includes requirements for bioburden testing, sterility testing, and biological indicator usage.
- Physical and chemical monitoring requirements are detailed in the standard, specifying the need for regular monitoring and documentation of critical process parameters. This includes requirements for calibration of monitoring devices, establishment of acceptable ranges for process parameters, and documentation of process records.
- Product compatibility with ethylene oxide sterilization must be demonstrated, including consideration of materials’ ability to withstand the process conditions and the potential for harmful residuals. The standard provides guidance on acceptable levels of ethylene oxide residuals and methods for their determination.
- Environmental and safety considerations are addressed, as ethylene oxide is both toxic and flammable. The standard includes requirements for safe handling, storage, and disposal of ethylene oxide, as well as monitoring of workplace exposure levels and environmental emissions.
- Documentation requirements are extensive and include specifications for process parameters, validation protocols and reports, routine monitoring records, and change control procedures. The standard emphasizes the importance of maintaining complete and accurate records of all aspects of the sterilization process.
- Quality management system integration is essential, as the standard requires that the sterilization process be managed within an appropriate quality management system. This includes requirements for personnel training, equipment maintenance, process monitoring, and continuous improvement.
- Routine process monitoring and control requirements ensure that the validated process remains effective over time. This includes regular monitoring of process parameters, biological indicators, and physical/chemical indicators, as well as periodic requalification of the process.
- The standard addresses product release requirements, including the criteria that must be met before sterilized products can be released for use. This includes verification that all critical process parameters were met during the sterilization cycle and that all required testing has been completed successfully.
- Change control procedures are specified to ensure that any modifications to the sterilization process, equipment, or products are properly evaluated and validated before implementation. This includes requirements for assessing the impact of changes on process effectiveness and product safety.
- Maintenance and calibration requirements ensure that all equipment used in the sterilization process remains in proper working order and provides accurate measurements. This includes regular maintenance schedules, calibration procedures, and documentation requirements.
- Review and audit requirements help ensure ongoing compliance with the standard and effectiveness of the sterilization process. This includes periodic review of process data, trend analysis, and internal audits of the sterilization program.
- The standard recognizes the importance of continuous improvement and includes requirements for monitoring process effectiveness, analyzing trends, and implementing improvements when opportunities are identified. This helps ensure that the sterilization process remains effective and efficient over time.
