What is Ethylene Oxide?
Ethylene Oxide (EtO) is a simple cyclic ether. At room temperature it is a gas, but becomes liquid below 10.7°C. It is vitally important in the production of many chemicals and products such as antifreeze, paints and detergents. EtO gas is widely used in hospitals worldwide for the sterilization of medical devices and equipment and is a growing popular alternative to radiation. 122,000 kilograms per year is used for sterilization the US alone.
How ETO Sterilizes
Pure EtO can be used as a sterilizing gas, it can destroy microorganisms by alkylating (attaching to) enzymes and DNA, causing their inactivation. To accomplish this, Ethylene Oxide first needs to penetrate materials and plastics. In order to speed up this process the gas is usually heated to 38°C or 54°C, this is known as low temperature sterilization and is compatible which a much wider range of materials compared to steam and dry heat processes.
High Material Compatability
Ethylene Oxide (EtO) maintains excellent material compatability across a wide range of commonly sterilized items as compared to other common methods of sterilization (see graph below)
Graph produced using data from AAMI TIR17:2008. Data points indicate the average compatability rating for all materials in that category
This makes EtO an excellent choice for sterilization of a wide range of items including; Scopes, Catheters & Tubes, Surgical Instruments, Electrical Equipment (Batteries Seperately), Syringes, Gowns and Masks, Bandages & Dressings, Respirators, Sutures, Stent Sets, Probes, Plastic and Rubber Tubing
Cycle Stages and Duration
Preparation - 1 Hour
The initial phase of the cycle ensures that all items are heated to 54°C and the gas to fully diffuse from the ampoule or canister.
Sterilization - 3 Hours
In this phase, the temperature is maintained at 54°C and the items are exposed to the EtO gas, allowing sterilization to take place. The cabinet is constantly under negative pressure, so that in the event of a leak, gas will be expelled through the exhaust.
Aeration - 12 Hours
After sterilization, the gas requires time to diffuse from the items and liner bag. The Axis system has in-cabinet aeration, so that a separate aeration room is not required. In this way, operators are kept safe from any potential exposure.
Services Required
The sterilizer requires only a power source and an outlet pipe. Thanks to the unique liner bag system, drainage channels, separate air/gas supplies or water lines are not required.
Ethylene Oxide is suitable for the sterilization of a wide range of medical instruments and devices
Typical instruments include; heat labile endoscopes, rigid scopes, scalpels and metal instruments, tubing, catheters and electronic equipment (if batteries processed seprately)