Autoclave Operation

CAUTION:  Only personnel with adequate training on autoclave use should be permitted to operate an autoclave.  Personnel should wear proper personal protective equipment, i.e., heat resistant gloves, eye protection, face protection, arm protection, etc., particularly when unloading the autoclave. 

Regularly inspect your autoclave components for proper operation.  Autoclave door clamps and seals should be inspected for wear and damage.  Also remove debris from the autoclave chamber floor drain and rubber door seal.  If a problem is found, promptly notify your area supervisor who will call an authorized service representative. DO NOT OPERATE THE AUTOCLAVE UNTIL IT HAS BEEN REPAIRED PROPERLY.

At the end of a decontamination cycle make sure that the pressure in the autoclave chamber is at  zero before opening the door.  Slowly crack open the autoclave door and allow the steam to gradually escape from within the autoclave.

CAUTION:  Opening the autoclave door too quickly may result in glassware breakage and/or steam burns on your skin.  The decontaminated materials should be allowed to cool for 10 minutes before they are taken out of the autoclave.

THINGS TO AVOID:

• Avoid dead air pockets where steam cannot penetrate (ie., closed screw cap tubes) because temperature within the air pocket is much lower than the saturated steam.

• Avoid dry packages, add some water to the load.  To avoid creation of infectious aerosols while adding water, trickle water down the sides of the container instead of pouring water directly onto the material in the container.

1. Processing Times

After loading and starting the autoclave, processing time starts after the autoclave reaches normal operating conditions: Temperature = 121oC (250oF); Pressure = 15 psi. 

Decontamination cycle times vary, i.e. type of load, load volume (loosely-packed or tightly-packed), container type (polypropylene, glass, stainless steel), and type of material to be decontaminated.  Therefore, processing times will vary according to the conditions of each decontamination cycle.  In general, the larger the load, the longer it will take to decontaminate.

The processing time to decontaminate laboratory and medical waste is at least 60 minutes (unless a shorter interval has proven effective when tested with biological indicators).  Add additional time as necessary if polypropylene containers are used. 

A minimum of at least 90 minutes is recommended for decontaminating waste in low-sided polypropylene containers with bags half-filled and loosely-gathered.  If bags are tightly-closed, a processing time of 120 minutes is recommended.  If your autoclave is equipped to operate at 132oC (270oF), you may be able to reduce processing time if the Geobacillus stearothermophilus spores are killed at the shorted cycle time.

Suggested Autoclaving Times:
A minimum decontamination processing time of 60 minutes is recommended for materials in metal pans with the lid removed. 

The US Environmental Protection Agency (EPA) has reported that ”Infectious wastes from departments of health care facilities may be rendered noninfectious by subjecting the waste to autoclave temperatures of 121oC (250oF) and 15 minutes of prevacuum of 15 psi for the following dwell times when proper containers are used:”

EPA Recommended Decontamination Processing (Dwell) Time