Autoclaves and Sterilizers Information

Autoclaves are used for applications requiring constant pressure and temperature for long periods of time. Common applications include the sterilization of instruments and polymerization of rubbers and plastics. Autoclaves and sterilizers may use a number of technologies to perform equipment sterilization. These include heating, chemical sterilization, or ultraviolet light.

The majority of autoclaves function using some form of heat. In all of these cases, the autoclave must maintain a temperature of at least 246 degrees for 30 minutes in order to fully sterilize equipment. Both dry heat and steam heat autoclaves are available. Steam autoclaves are far more common, using heated, vaporized water to kill pathogens. Dry heat autoclaves use dry heat to sterilize instruments. They are used in cases where heating is the preferred method of pathogen destruction, but moisture could damage the inserted instruments, either through immediate contact or rust generation.

Chemical sterilizers are used in situations where heating could damage sensitive instrumentation, including plastic and rubber devices, fiber optics, etc. They do require external venting systems to remove the chemical agents from the sterilizer. These fans or drain systems may be integral to the device, although some models can be connected into existing exhaust systems.

Chemical sterilizers can be broken down into two major groups, cold sterilizers and gas autoclaves:

  • Cold sterilization autoclaves use a cold sterilization liquid to sterilize the contents. Cold sterilization liquids have been developed to enable sterilization or high-level disinfection.
  • Gas autoclaves, often called chemicalves, use a vapor solution to sterilize its contents. Unlike the humid environment produced by conventional steam, the unsaturated chemical vapor method is a low-humidity process. No time-consuming drying phase is needed, because nothing ever gets wet.

Gas autoclaves generally require less heat-up time, as well, which allows for greater instrument turnover. Common sterilizing agents include formaldehyde gas and ethylene oxide. FDA standards prohibit some of these devices being used in conjunction with medical or dental instrumentation due to the possibility of residual chemical deposits on instrumentation.

Ultraviolet autoclaves and sterilizers produce UV light exerting a lethal effect on unwanted disease causing organisms. They can destroy pathogens, bacteria, mold spores, yeast, protozoa, fungi and algae.