What Is a Plasma Sterilizer?
A plasma sterilizer is a device that combines hydrogen peroxide gas and a high-frequency generator to generate low-temperature plasma, which kills microorganisms such as bacteria through the action of free radicals generated in the plasma.
In addition to its high sterilization efficiency, it has the advantage of completing the process in a short time, and it is also safe because it turns into water after the process. No water supply or drainage facilities are required to install the unit.
Therefore, the unit can be used immediately after power is supplied. Unlike autoclaves, plasma sterilizers are low-temperature devices and can be used for sterilizing items that cannot be sterilized by high-pressure or high-temperature steam. It is sometimes referred to as a “hydrogen peroxide gas plasma sterilizer.
Uses of Plasma Sterilizers
Plasma sterilizers can sterilize metal, plastic, and glass products. In particular, plasma sterilizers are used to sterilize instruments that cannot be autoclaved or sterilized by high-pressure steam due to their low heat resistance.
1. Medical Field
In the medical field, the sterilizer is used for pre-maintenance sterilization of intraocular lenses, artificial joints, and other medical devices such as endoscopes and surgical instruments. Endoscope tubes used in endoscopic surgery and probes used in ultrasound guidance are used frequently and must be sterilized efficiently.
Conventional methods include sterilization using ethylene gas and disinfection by immersion, but there are issues such as avoiding the toxicity of ethylene gas and shortening sterilization time. Plasma sterilizers are highly safe and can shorten sterilization time.
2. Chemical Field
In the chemical field, plasma sterilizers are used for research and development of materials such as artificial organs and medical equipment in the medical field mentioned above. Other applications include sterilization of equipment for bio-clean room facilities.
3. Livestock Breeding
In the livestock industry, our products are used for sterilization of artificial insemination equipment, sterilization of equipment for SPF animal facilities, and other applications.
Principle of Plasma Sterilizers
Plasma sterilizers generally use a high-frequency discharge technique for hydrogen peroxide gas. Specifically, sterilization is performed by the following procedure.
- Diffuse hydrogen peroxide vapor in a vacuumed sterilization chamber
- Hydrogen peroxide molecules are electromagnetically excited to a low-temperature plasma state
- Sterilization is performed by free radicals produced by plasmaization
It is common to repeat several cycles of hydrogen peroxide vapor diffusion and plasma sterilization during a single equipment operation. Suitable for sterilization of metal, plastic, and glass products.
Types of Plasma Sterilizers
Plasma sterilizers are available in a variety of sizes, including small (chamber capacity: approximately 30 L), medium (chamber capacity: approximately 80 L), and large (chamber capacity: approximately 140 L). Sterilization time also varies by product, with some products requiring around 50 or 70 minutes for sterilization, while others can complete sterilization in as little as 20 or 30 minutes. It is necessary to use the appropriate product for the intended use.
Some devices are more effective by plasmaizing not only hydrogen peroxide but also other agents such as peracetic acid. Radicals obtained by plasmaizing peracetic acid include perhydroxyl radicals, OOH, and CH3CO.
Other Information on Plasma Sterilizers
1. Safety of Plasma Sterilizers
Radicals produced by hydrogen peroxide and plasmaization are not persistent. Plasmatization is a safe method of sterilization because it breaks down into water and oxygen at the end of the sterilization process.
In addition, all stages of the sterilization cycle operate in a cool, dry environment, which prevents damage to heat- and moisture-sensitive compliant materials.
2. Materials Unsuitable for Plasma Sterilizers
Plasma sterilizers are not suitable for sterilizing cellulose materials such as linen, gauze, cotton, paper, cardboard, wood, Styrofoam, powders, liquids, etc.