Autoclaves provide a physical method for disinfection and sterilization. They work with a combination of steam, pressure and time. Autoclaves operate at high temperature and pressure in order to kill microorganisms and spores.
They are used to decontaminate certain biological waste and sterilize media, instruments and lab ware. Regulated medical waste that might contain bacteria, viruses and other biological material are recommended to be inactivated by autoclaving before disposal.
Autoclave Cycles:
- To be effective, the autoclave must reach and maintain a temperature of 121° C for at least 30 minutes by using saturated steam under at least 15 psi of pressure. Increased cycle time may be necessary depending upon the make-up and volume of the load.
- The rate of exhaust will depend upon the nature of the load. Dry material can be treated in a fast exhaust cycle, while liquids and biological waste require slow exhaust to prevent boiling over of super-heated liquids.
Material
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Recommended for:
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Liquids cycle
(Slow Exhaust)
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Use with glass containers with vented closures; 2/3 full only
•Liquid media
•Nonflammable liquids
•Aqueous solutions
•Liquid biological waste
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Solids or Dry cycle
(Fast Exhaust)
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- Glassware: empty and inverted
- no tight or impermeable closures
- Dry hard items, either unwrapped or in porous wrap
- Metal items with porous parts
- Other porous materials
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Wrapped Goods or Pre vacuum cycle
(Clean: Fast Exhaust
Dirty: Slow Exhaust)
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- Glassware that must be sterilized upright and/or can trap air
- Wrapped dry items that can trap air
- Pipette tip boxes
- Sharps decontamination
- (in collection containers)
- Biohazard waste decontamination, in autoclave bags; can be wet or dry
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Compatible/Incompatible Materials
AUTOCLAVE-COMPATIBLE MATERIALS
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AUTOCLAVE-INCOMPATIBLE MATERIALS
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- Tissue Culture Flasks
- Surgical Instruments
- Glassware
- Pipette tips
- Media Solutions
- Animal food and bedding
- Waste
- Polypropylene (Secondary containers)
- Stainless steel
- Gloves
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- Acids, bases and organic solvent
- Chlorides, sulphates
- Seawater
- Chlorine, hypochlorite, bleach
- Non-stainless steel
- Polystyrene(PS)
- Polyethylene(PE)
- Low density (LDPE) and High density polyethylene(HDPE)
- Polyurethane
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Never autoclave:
· Flammable, reactive, corrosive, toxic or radioactive materials
· Household bleach
· Any liquid in a sealed container.
· Any material contained in such a manner that it touches the interior surfaces of the autoclave.
· Paraffin-embedded tissue.
Glass
- Only Pyrex® or Type I borosilicate glass is autoclavable. When autoclaving liquids in Pyrex® containers, do not fill more than 2/3 full and do not seal the container.
Plastic
- Polypropylene is an inexpensive resin that can resist autoclave temperatures. Polypropylene containers are often used as secondary containers to hold materials that are autoclaved. Polycarbonate can also withstand high temperatures. Polystyrene (PS), polyvinyl chloride (PVC), nylon, acrylic, low-density polyethylene (LDPE), and high-density polyethylene (HDPE) lab ware and polyurethane tubing are not autoclavable under any conditions.
Gloves
- Gloves must be placed inside of an autoclavable biohazard bag and exposed to a steam setting; gloves will melt slightly but will not burn when autoclaved in this manner.
Stainless steel
- Most metals are designed for extreme conditions and are intended to be sterilized. Make sure to remove any plastics, liners and other items that may melt or combust.
Paper
- Paper is combustible and should not be placed directly inside an autoclave. It should be autoclaved in a waste bag on a biobag setting to prevent fire.
Media Solution
- No liquid should be sealed in a container and autoclaved. Fill 2/3 of the container and loosen caps. They should autoclaved in a steam producing cycle.
Pipette tips
- Most pipette tips are autoclavable. Some of these tips are plastic, some are high density polyethylene. In general, pipette tips should only enter the autoclave as waste inside of an approved biohazards bag and always sterilized on a steam-producing setting.