Anesthesia Machines and Scavengers




Anesthesia machines and vaporizers must be inspected, recalibrated if necessary, and recertified annually to ensure high-quality anesthesia to research and teaching animals, and waste anesthetic gas (WAG) must be scavenged with equipment in good working condition to provide a safe working environment for personnel.


The Guide for the Care and Use of Laboratory Animals notes that appropriate anesthesia is a critical component of the animal care and use program. Properly functioning gas anesthesia machines are key to the delivery of the anesthetic agent to the animal and to the safety of personnel. Preventive maintenance, calibration, and recertification are essential to ensuring that machines are working effectively.

WAG is an occupational health and safety concern due to associated health risks. Exposure to WAG can lead to fatigue, drowsiness, nausea, headache and difficulties with coordination and judgement. Chronic exposure to WAG can adversely affect the liver, kidney and central nervous system and have possible negative reproductive effects. To protect the health and safety of users, WAG must be scavenged, and scavenging equipment must be maintained in good working condition.


All anesthesia machines must be inspected, recalibrated if necessary, and recertified annually by a qualified service provider or the manufacturer. It is the responsibility of the investigator to contact the servicing vendor, pay for the service, and maintain records for their machines. All machines must have a label or sticker on the machine indicating the latest date of recertification. Any machine with expired certification or that fails recertification must be labeled “Do Not Use” and taken out of service until recertification or repairs are completed.

Before each use, machines should be checked for leaks, cracks, breaks and tightness of hose connections to ensure that the machine can function properly and protect users from WAG. WAG must be scavenged to protect the health and safety of the user. The safest way to scavenge WAG is using an active scavenging system with an active airflow system to sequester WAG from the user (e.g. using a chemical fume hood, biosafety cabinet ducted to the outside or a vacuum snorkel). If active scavenging cannot be used, WAG must be passively scavenged using a charcoal filter.

An online training module is provided by the Division of Animal Resources: Isoflurane Anesthesia Using a Vaporizer


SomnoSuite anesthesia machines do not need to be recertified, as indicated by the manufacturer.


Approved Date

Revised Date

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