Waste Anesthetic Gas


Outline the health and safety guidelines used by students, faculty and staff involved in the administration of anesthetic gases.


Waste anesthetic gas (WAG) is a term commonly used to describe the potential employee exposure to anesthetic gases in the environment during a surgical procedure. Employees with the greatest potential for exposure are anesthetists, post-operative care staff, surgeons (depending on the type of surgery), dentist, and researchers.

The most widely used anesthetic gases are halogenated ethers such as Forane (Isoflurane), Ethrane (Enflurane), Halothane, Desflurane, and Sevorane (Sevoflurane) coupled with Nitrous Oxide. Exposure to these gases can occur as they escape into the environment during the anesthesia administration process. These gases have very poor warning properties and odor is not an adequate indication of overexposure. The Registry of Toxic Effects of Chemical Substances reports adverse health effects in addition to central nervous system effects associated with the use of anesthetic gases. Epidemiological studies have also indicated congenital abnormalities and adverse effects on the liver and kidneys. Nitrous oxide and halogenated anesthetics have been described as tumorigens, mutagens and human reproductive effectors.  


  • The oversight of the University WAG program. 
  • Ensuring compliance with all federal, state, and local regulations. 
  • Area and personal air monitoring as requested to determine exposure risks. 
  • Ensuring medical surveillance services are available when required.

Signs and Symptoms of Exposure to Waste Anesthetic Gases

Acute Exposure

nausea, vomiting, skin irritation, nose/throat/respiratory irritation, headache, dizziness, and drowsiness.

Chronic Exposure

hypotension, tachycardia, respiratory depression, and elevated blood glucose levels

Exposure Limits

National Institute for Occupational Safety and Health (NIOSH)

NIOSH has recommended a one-hour ceiling limit of 2 ppm (15 mg/m3) for all halogenated agents. The NIOSH recommended exposure limit for Nitrous Oxide is 25 ppm as an eight-hour time-weighted average. When used in combination with Nitrous Oxide, the NIOSH recommended exposure limit (REL) for halogenated anesthetic gases is 0.5 ppm.

Occupational Safety and Health Administration (OSHA)

OSHA does not have an established permissible exposure limit (PEL) for anesthetic gases.