Autoclave Safety
Overview
An autoclave is a piece of equipment widely used in biomedical laboratories at Weill Cornell Medcine (WCM). Autoclaves pose many
hazards including physical hazards (e.g. heat, steam and pressure) and biological hazards. This Update provides guidance on the
usage of autoclaves at the Medical College and off-site locations.
Each autoclave has unique characteristics. Review and understand the owner’s manual before using any autoclave for the first time
and as needed thereafter. Contact the manufacturer to request on-site training as needed. Ensure the owner’s manual is readily
available in case questions arise during operation. EHS can be contacted for general autoclave safety training and guidance.
Maintenance is vital to the effective and safe use of an autoclave. Follow the manufacturer’s recommendations for preventative
maintenance and ensure all contractors are approved by the manufacturer. Maintenance should include periodic efficiency tests (e.g.
Bacillus stearothermophilus spore testing) to ensure the autoclave is functioning properly.
Applicability
Faculty, staff, students, and visitors who use autoclaves.
Responsibilities
Environmental Health and Safety (EHS) provides assistance and training for autoclave safety as requested and update informational
resources as necessary.
Principal Investigators and Laboratory Managers establish and update policies and procedures for their personnel and ensure that
they are properly trained in and compliant with safety requirements and familiar with this Update.
Laboratory Personnel working with autoclaves must follow these guidelines and contact Environmental Health and Safety for any
needed assistance and training.
Procedure
Utilize the following autoclave safety practices.
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General Precautions
 Do not use an autoclave for other than its intended use.
 Before using the autoclave, check inside it for any items left by the previous user that could pose a hazard (e.g. sharps).
 Clean the drain strainer before loading the autoclave.
 Load the autoclave properly, as per the manufacturer’s recommendations.
 Use the appropriate cycle for the material being autoclaved (e.g. liquid, pre-vacuum, gravity), per the manufacturer’s instructions.
 Ensure that items to be autoclaved do not contain corrosives (e.g. acids, bases, phenol), solvents or volatiles (e.g. ethanol,
methanol, chloroform) or radioactive materials. Contact EHS or review the EHS Program Manual, section 5.2 - Waste Disposal
Procedures, for proper decontamination and disposal procedures.
 Do not autoclave vertebrate animal carcasses. Vertebrate animal carcasses should be disposed via the Research Animal
Resource Center (RARC).
Containment Materials
 Prevent bottles from shattering during pressurization by ensuring the caps of containers are loosened before loading; this
includes both empty and liquid filled bottles.
 Expanding vapor in bottles during heating can also lead to rupturing. Containers with liquids should not be filled completely.
 Containers should only be ½ - ¾ full to allow for vapor expansion.
 Never place individual glassware pieces directly on the autoclave bottom or floor. These items should be placed in a heat
resistant plastic tray on a shelf or rack.
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CONTINUED: Autoclave Safety
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 Only use compatible plastics with the autoclave. Certain plastics are cannot be autoclaved. Plastic types are identified by
manufacturing initials that are imprinted on the container bottom.
 Use: Polypropylene (PP, recycle #5); Polycarbonate (PC); Do Not Use: Polyethylene (PE, recycle #1); High-density polyethylene
(HDPE, recycle #2). Nalgene Labware/Thermo Scientific’s Autoclaving webpage provides additional plastic considerations.
 For secondary containment, use autoclave trays made out of polypropylene, polycarbonate or stainless steel. The trays should
have a solid bottom and walls to contain the contents and catch spills.
 Do not use trays or tubs that are cracked, warped or compromised.
Proper Use of Liquid
 Add 1/4 to 1/2 inch of water to the tray so the bottles will heat evenly.
 Ensure sufficient liquid is packed with contents of autoclave bags if dry (e.g. 10 ml of water; a zip lock bag containing water).
Tape
 Place autoclave tape on the material being autoclaved (e.g. bag; bottle; or tray; etc.) as an additional verification of sterilization
by the autoclave.
 Use only lead-free autoclave tape. Replace lead-containing autoclave tape with lead-free alternatives. Typically, tapes with
stripes (////) contain lead, and tapes which display the word “Autoclaved” as an indication of steam sterilization are lead-free.
Lead-free options are available from WMC Preferred Vendors such as VWR and Fisher-Scientific.
 Unused rolls of lead-containing autoclave tape should be disposed via EHS as chemical waste.
Packing Bags into the Autoclave
 Avoid packing bags tightly within the autoclave to ensure that heat & steam can circulate.
 Bags should be sealed loosely to allow for effective steam penetrate.
 Do not allow bags touch the interior walls of the autoclave.
Latching and Opening the Autoclave Door
 Make sure the door of the autoclave is fully closed (latched).
 Wait until the pressure gauge reads zero before opening the autoclave door.
 Before removing autoclaved items, wait 5 minutes for loads containing only dry glassware, and 10 minutes for autoclaved liquid
loads.
 Wear heat-resistant gloves when opening the autoclave door after a cycle. If there is a sharps hazard (e.g. biological waste),
wear heat AND cut resistant gloves. At a minimum, when removing items from an autoclave, a rubber apron, rubber sleeve
protectors and heat-resistant gloves should be worn.
Handling Autoclaved items
 Before touching with ungloved hands:
 For non-liquid loads, let the glassware cool for 15 minutes.
 For liquid loads, let liquids stand for a full hour.
 Alert others in the area that a heat hazard is present.
In the Event of Injuries
 Report any injuries sustained during the autoclave process to the appropriate supervisor, EHS, and Workforce Health and Safety
(WHS).
References
EHS Program Manual, Section 5.2 - Waste Disposal Procedures
Nalgene Labware - Technical Data. “Autoclaving”
University of California at San Diego - Autoclaving Guidelines for Sterilization of Lab Equipment
University of California at Berkley – “Safe and Effective Use of Autoclaves”
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