Lab Ventilation Systems

Lab Ventilation Systems for Your Autoclave

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Written by: Scott Mechler

BS Mechanical Engineering, Mechanical Engineer

The need for a proper lab ventilation system when running a sterilization cycle in your laboratory autoclave cannot be understated. Ventilation for autoclaves assures that the various odors, steam moisture and low-levels of chemical vapors that come from the sterilization process do not escape further into the laboratory setting. When not regulated correctly with an adequate lab ventilation system, these vapors can pose serious health and safety concerns for lab personnel.

Dangerous consequences of faulty ventilation for autoclaves

Take for example a recent incident involving several staff and students at Massey University’s Albany campus in New Zealand. After complaining of sore throats, headaches, nausea and itchy eyes, it was discovered that the faculty and students had been exposed to fumes that had incorrectly vented into a student center. Further investigation into the unexplained symptoms found that days earlier the affected staff and students had been exposed to formaldehyde when a container of embalmed pig carcasses was opened without being properly cleaned first. Ultimately it was concluded that the smell was caused by material from an autoclave used in the science building to dispose of biological material. The unpleasant odor, as it turns out had inadvertently been ventilated into the student center. At the conclusion of the investigation it was determined that the school’s ventilation standards had been subpar for quite some time.

The importance of lab ventilation systems

As you can see by the above example, ventilation for autoclaves is a critically important element to the sterilization process. Your autoclave, which is essentially a giant steam oven, has the potential to expel unwanted exhaust at various points in a cycle—whether it’s during the sterilization process when steam is being condensed down to water through an exhaust line, or once you’ve opened the chamber door after your cycle has finished. Large autoclaves used to sterilize liquid loads can produce a billow or cloud of vapor, and without a functionally adequate lab ventilation system, that vapor can escape and do some serious harm to you or your surroundings—especially if your autoclave is situated in a small room.

Other unintended consequences include:

  • False smoke alarms
  • Triggering low-temp sprinkler heads
  • General discomfort
  • Structural building concerns (i.e. weakened drop ceilings)

The most critical of consequences involves the health and safety of your laboratory personnel. As evidenced in the above story, the sterilization of something like formaldehyde can create noxious fumes, which can lead to dangerous if not downright fatal consequences. It’s never a good idea to sterilize any liquid capable of producing a noxious fume without a functioning ventilation system. The proper safety personnel should always be involved when sterilizing something outside of your standard operating procedure.


Lab ventilation systems come in all shapes and sizes—some come in the form of a canopy exhaust hood situated over the autoclave, while others are positioned directly over the door of the autoclave itself. The most common type of ventilation system involves a fan or intake system that uses forced air to draw all moisture and vapor into the hood. Another solution is to construct a large canopy hood without a fan above the autoclave that allows any steam or vapor from the chamber to flow directly into it and out of the room. It is recommended that the canopy hood be directly connected to exhaust ductwork. Other recommendations include:

  • Doors to your autoclave rooms should be kept closed.
  • Autoclave door should not be opened too soon after a run is finished.
  • Crack the door initially to let out majority of steam. Fully open slowly to enhance capture of steam.
  • Once the door has been opened, the operator should allow several minutes for the steam and odors to escape and the load to cool somewhat prior to removing contents from the autoclave.
  • Do not discard liquid from bag down sink if this will create odors.

Please contact us with any inquires or if you would like more information on lab ventilation systems.

17 Questions to Ask Before Buying Your Next Autoclave

17 Questions to Ask Before Buying Your Next Autoclave

With so many models, sizes, options and components to choose from, how can you ever really know exactly what you need to make the most out of your investment?

These questions will help you to make informed decisions by outlining what is most important to consider and know about owning an autoclave.