Purpose of the Formaldehyde Cycle on an Autoclave

Medical and laboratory equipment is often sterilized with heat. An autoclave, a specialized piece of equipment, uses steam to generate extremely high temperatures that can kill microbes and other contaminants. The formaldehyde cycle on an autoclave is used to sterilize equipment that cannot handle such high heat.

Low Temperature Steam and Formaldehyde Sterilization

• During normal sterilization in an autoclave temperatures can reach 160 degrees Celsius. Wet heat is more effective than dry heat. Therefore using steam can enable sterilization at temperatures around 121 degrees Celsius. When used in combination with formaldehyde, a common disinfectant, sterilization can be accomplished at temperatures as low as 50 degrees Celsius. This is called Low Temperature Steam and Formaldehyde (LTSF) Sterilization.

Uses

• Many pieces of medical equipment are heat-sensitive. Instruments that are hollow or made of plastic, such as endoscopes, fall into this category. However, throwing them out after each use would be costly. LTSF sterilization allows efficient cleaning and reuse of these items.

The Cycle

• The items are pre-heated before the formaldehyde enters the system. A series of steam flushes removes air from the chamber and moistens any bacteria on the items that will be sterilized. This makes them more susceptible to the formaldehyde.The formaldehyde solution then enters the chamber and is converted into a gas. Steam helps keep the chamber at the appropriate temperature. When the equipment is fully sterilized the systems is emptied and flushed by air pulses to remove the formaldehyde safely.