Excessive exposure to anesthetic gases can result in toxic injury to operating room personnel. OSHA recommends that release of waste anesthetic gases be kept to a minimum.


Agents of concern:

(1) nitrous oxide

(2) halogenated agents (halothane, enflurane, methoxyflurane, trichlorethylene, chloroform)



(1) Properly collect and vent waste gases from the facial mask. A scavenging system is included in modern anesthesia carts.

(2) Do not open the anesthetic valves to the mask until the mask is placed.

(3) Turn off the anesthetic gas as soon as complete. Maintain oxygen flow until the scavenging system is flushed.

(4) Make sure the anesthesia equipment is functioning properly. Routine maintenance should include checks for gas leaks from the anesthesia circuit.

(5) Monitor the operating rooms for excessive gas concentrations.

(6) Ensure good general ventilation to the operating room.

(7) Have ongoing surveillance of operating room personnel for signs of toxic effects, including abnormal pregnancy outcomes.


Gas monitoring:

(1) The atmospheric concentration of a halogenated agent should not exceed 2 parts per million.

(2) The 8 hour time weighted average concentration for nitrous oxide should be <= 25 parts per million when used as the sole anesthetic agent.


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