Sterilization, Cleanrooms and Packaging
ISO 11135: Ethylene Oxide Sterilization
ISO 11135 covers ethylene oxide (EO) sterilization of health care products, from developing the process to validating it and controlling every routine load. EO is widely used for devices that can't tolerate heat or radiation, which makes this standard central for many single-use device makers and their contract sterilizers.
At a Glance
- Standard
- ISO 11135
- Subject
- Ethylene Oxide Sterilization
- Group
- Sterilization, Cleanrooms and Packaging
- Industries
- 3 industry guides reference it
A plain-language summary of scope, not the standard itself. Buy the current edition from the publisher and check which edition your auditor or market expects.
What It Covers
The standard addresses characterizing the sterilizing agent and the process, defining the product and its packaging, and defining the process stages: preconditioning, conditioning, EO exposure and aeration. It covers the sterilization equipment, the microbiological approach used to show lethality, typically with biological indicators or process challenge devices, and how load configuration affects the process.
Validation runs through installation, operational and performance qualification, with performance qualification covering both microbiological and physical aspects. Routine monitoring and control then confirm each cycle met its specified parameters before product is released, and the process is requalified periodically and reassessed when product, packaging or loading changes.
Because EO leaves residuals on product, the sterilization process connects to biological evaluation, where residual levels are assessed under the ISO 10993 series. Many manufacturers outsource EO sterilization, so supplier controls and a clear split of responsibilities between manufacturer and sterilizer matter as much as the cycle itself.
Who It Applies To
- Manufacturers of EO-sterilized single-use devices and kits
- Contract sterilizers running EO cycles for device makers
- Firms adding new products to an existing validated EO cycle
- Companies evaluating a change of sterilization site or method
What Auditors Check
Validation Package
Installation, operational and performance qualification records for the cycle and chamber actually in use, including microbiological and physical performance qualification.
Adding Products to a Cycle
A documented assessment showing a new or changed product is no harder to sterilize than the validated challenge before it enters the cycle.
Routine Release Records
Cycle records with parameters inside specification, the release evidence used, and a defined, documented release decision.
Requalification
Periodic requalification and change-driven reassessment, with the rationale for what was and wasn't repeated.
EO Residuals
Residual assessment consistent with the biological evaluation and with the aeration parameters in use.
Contract Sterilizer Controls
A quality agreement defining who validates, who releases and who is told about changes or deviations, backed by supplier monitoring.
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Industry Guides That Reference ISO 11135
ISO 11135
Check Your Quality System Against ISO 11135
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