Types of Sterilizers

The Environmental Protection Agency categorizes sterilizers as a public health antimicrobial product. Sterilizers kill all forms of microbial life, which makes them different from other antimicrobial products like disinfectants, sanitizers or antiseptics. To qualify as a sterilizer, a sterilizing agent must pass a test against 120 carriers. If the agent killed all forms of microbial life during each test, it qualifies as a sterilizer. If the agent fails once or twice, it qualifies as a sporicide, which can still kill bacterial spores.

Steam

• When steam reaches high temperatures under pressure, you can use it to sterilize items such as medical instruments and industrial equipment. An autoclave is a controlled steam machine. Air is removed from the vessel inside the autoclave and pressurized steam is applied to items that need to be sterilized. Autoclaves are available in different sizes and are often tailored to specific items such as small medical instruments.

Dry Heat Ovens

• A dry heat oven provides an alternative to an autoclave for sterilizing items that will rust in an autoclave, such as certain dental instruments that are not stainless steel. The dry heat oven reaches temperatures of more than 300 degrees Fahrenheit compared to autoclaves, which reach about 270 degrees Fahrenheit.

Gaseous and Liquid Chemicals

• Certain gaseous chemicals such as ethylene oxide, formaldehyde, propylene oxide and oxidizing gases such as ozone, chlorine dioxide and even hydrogen peroxide qualify as sterilizers. Ethylene oxide is widely used, and features almost ideal sterilization properties. Others gaseous chemicals, such as hydrogen peroxide, are used more selectively and only on surfaces.

Radiation

• Radiation, in the form of X-rays, gamma radiation and electrons, is used to sterilize. Using a direct current or alternating current radiation machine, electromagnetic radiation can eliminate microorganisms on an atomic level, making it completely effective against bacterial spores. As a result, this method of sterilization is both cost-efficient and consistent.