A sterile medical device is a device that does not contain live microorganisms. Medical devices manufactured under standard manufacturing conditions in accordance with ISO 13485 requirements may contain microorganisms, albeit in small numbers, before sterilization. Such medical devices are not sterile.
The purpose of sterilization is to neutralize microbiological contaminants, thereby rendering the non-sterile medical device sterile.

ISO 11135 specifies requirements that, if met, provide an ethylene oxide sterilization process with appropriate microbicidal activity to sterilize medical devices. Furthermore, compliance with specifications ensures that this efficacy is both reliable and reproducible, so that the probability of a microorganism present in the product after sterilization can be estimated with acceptable confidence.

While ISO 11135 includes validation activities for cylinder systems, ISO 14937 standard is based on cartridge systems.

In this context, the reproducibility of sterilization efficiency is shown depending on the bioburden of the products. Variables are controlled by physical, microbiological and chemical tests. Physical factors such as temperature, humidity, pressure should be monitored and their contribution to the sterilization process should be determined.

It should not be forgotten that the following factors directly affect the effectiveness of sterilization before the sterilization process. Therefore, it should be taken into account,

• Microbiological condition of raw materials and/or components,
• Validation and routine control of cleaning and disinfection procedures applied on the product,
• Control of the environment in which the product is manufactured or reprocessed, assembled and packaged,
• Control of hardware and processes,
• Control of personnel and personnel hygiene,
• Packaging form and packaging material of the product,
• Conditions in which the product is stored.