Autoclave Safety Prepared by Curt Speaker Environmental Health and Safety Penn State University

Disclaimer This presentation covers the basics of operating an autoclave. It is impossible to include specific information that would be applicable to all autoclaves. This presentation should be supplemented with hands-on training on the specific autoclave that you will be operating.

Autoclave Def. - A strong, pressurized, steam heated vessel, as for sterilization or cooking Properly used, autoclaves can be used to sterilize instruments, media and to sterilize infectious waste, making it safer to handle Uses a combination of temperature (250oF) & pressure (18 psi) to sterilize

Common Types of Autoclaves

Principle of Operation

Basic Operating Principles Arrange the load Set the operating controls Sterilize Unload

Preparation Ensure that the drain screen is clear of debris to allow proper circulation of steam Examine the door gasket for damage Arrange load to allow circulation of steam Provide secondary containment for liquids and infectious waste Use only borosilicate (Pyrex) glass Loosen caps or cover with foil

Setting the autoclave Use “Slow Exhaust” for all liquids and loads of infectious waste Use “Fast Exhaust” for low moisture items 30 minutes is the minimum time for sterilization; varies with organic load

Close the door Make sure all radial arms are inside of the door groove Tighten the door (clockwise) as tightly as possible Begin the sterilization cycle

End of cycle Turn the control handle to “off” (older models) Verify that the cycle is completed by observing the pressure gauge Slowly turn the door wheel (counterclockwise) to open door If any resistance is met, DO NOT force the door open!

End of cycle Steam will likely escape from around the door; do not stand too close and be sure to wear heat resistant gloves Open door no more than 1/2” and wait for chamber steam to dissipate - Why?

Dangers of opening the door too quickly Will cause rapid boiling of liquids Glass (even Pyrex) may crack if temperature changes too quickly There have been several injuries at PSU from residual steam in chamber

Review Prepare the autoclave for operation Ensure drain screen is clear Ensure door gasket is intact Arrange load to allow for circulation of steam Provide secondary containment for liquids and infectious waste Use only Pyrex glass Loosen caps or cover with foil or plug with cotton

Review Setting the autoclave Select “Slow exhaust” for liquids and waste “Fast exhaust” for low moisture items “Fast exhaust & dry” if drying is needed Use a minimum sterilization time of 30 minutes; materials with high organic contact may require longer sterilization times

Review Close the door and operate Make sure that all radial arms go into door groove Tighten handle (clockwise) as tight as possible Begin the sterilization cycle

Review End of cycle Turn control handle to “off” Verify cycle is complete by observing chamber pressure gauge Slowly open door 1/2” to allow chamber steam to escape Items inside will be extremely hot - handle with care & wear gloves!

Malfunctioning Equipment Autoclaves that do not seem to be functioning properly should be immediately reported to the Office of Physical Plant, 865-4731 Do not use malfunctioning equipment and tag it so that others do not use it!

References The majority of this information is taken from: Laboratory Safety : Principles and Practices, second edition, Diane Fleming, John H. Richardson, Jerry J. Tulis & Don Vesley, editors, ASM Press, 1995.

The End Questions ?