ISO 11135

What is ISO 11135?

ISO 11135:2014 is the international standard for the development, validation, and routine control of ethylene oxide, or EO, sterilization processes for medical devices. It applies in both industrial operations and health care facilities while recognizing differences between those settings.

The standard focuses on showing that the defined process can reliably deliver the required sterilization outcome and remain controlled during routine operation.

What is the current version of ISO 11135?

As of July 2026, the published edition remains ISO 11135:2014 together with Amendment 1:2018. The amendment revises material concerning single-batch release.

A replacement has reached the Final Draft International Standard stage. However, an FDIS is not the current published standard. Manufacturers should monitor publication and perform a documented transition assessment once the replacement edition is issued rather than prematurely citing it as effective.

What does EO sterilization validation cover?

A validation program establishes the product and process definition, equipment capability, exposure conditions, microbiological effectiveness, and evidence needed to support routine processing. It should account for the device, packaging, load configuration, manufacturing environment, and the capabilities of any contract sterilizer.

Routine controls then demonstrate that each cycle was delivered within the established process specification. Changes to the product, packaging, load, equipment, site, or process can trigger evaluation and possible requalification.

How are ethylene oxide residuals addressed?

Process validation under ISO 11135 is not the same as evaluating chemical residuals. EO-sterilized devices with relevant patient or user exposure should also be assessed under the current ISO 10993-7:2026 residual limits and test framework. Aeration conditions and residual testing therefore need to be coordinated with, but not substituted for, sterilization validation.

Is ISO 11135 automatically mandatory in every market?

No. A standard becomes relevant through applicable regulation, regulator recognition, conformity assessment expectations, or the manufacturer’s chosen method of demonstrating compliance. The exact regulatory role must be confirmed for each target market.

Sterilization evidence commonly forms part of technical documentation for EU MDR consulting and device submissions in the United States. Pure Global can coordinate those requirements through a broader market access program.