The common ethylene oxide sterilization process uses a vacuum process, generally using 100% pure ethylene oxide or a mixed gas containing 40% to 90% ethylene oxide (for example: mixed with carbon dioxide or nitrogen).

Properties of Ethylene Oxide Gas

Ethylene oxide sterilization is a relatively reliable low-temperature sterilization method. Ethylene oxide has an unstable three-membered ring structure and its small molecular characteristics, which make it highly penetrable and chemically active.

Ethylene oxide is a flammable and explosive toxic gas that starts to polymerize at temperatures above 40°C, so it is difficult to store. To improve safety, carbon dioxide or other inert gases are usually used as diluents for storage.

Ethylene oxide sterilization mechanism and characteristics

The principle of ethylene oxide sterilization is mainly through its non-specific alkylation reaction with microbial proteins, DNA and RNA. This reaction can replace the unstable hydrogen atoms on microbial proteins to form compounds with hydroxyethyl groups, causing the proteins to lose the reactive groups they need in basic metabolism, thereby hindering the normal chemical reactions and metabolism of bacterial proteins, and ultimately leading to the death of microorganisms.

Advantages of Ethylene Oxide Gas Sterilization

1. Sterilization can be performed at low temperatures, and items that are sensitive to temperature and humidity can be sterilized.

2. Effective on all microorganisms, including all microorganisms in bacterial spores.

3. Strong penetration ability, sterilization can be performed in the packaged state.

4. No corrosion to metals.

5. Suitable for sterilization of items that are not resistant to high temperatures or radiation, such as medical devices, plastic products, and pharmaceutical packaging materials. Dry powder products are not recommended for sterilization using this method.