Anesthetic Gases

One of the principal goals of general anesthesia is to prevent patients, both human and animal, from feeling pain during surgery. A common method of anesthesia is the purposeful inhalation of a gas that is known to provide general sedative effects and/or induce unconsciousness. These gases can be separated into two categories: Halogenated anesthetic gases/vapors and nitrous oxide. These may be administered in combination to produce surgical levels of anesthesia. Halogenated anesthetic gases/vapors and nitrous oxide are also commonly used during veterinary care or experiments in animal research.

Assay Technology anesthesia delivery
Anesthesia  Delivery
 Assay Technology (

Anesthetic gases and vapors that leak into the surrounding room are considered waste anesthetic gases (WAGs). If equipment is not set up or functioning properly or if the WAG is not properly exhausted or captured via scavenging, or if ventilation not adequate, healthcare workers, researchers, and veterinary staff may be exposed to WAGs. This exposure creates a risk of potentially developing adverse health effects. EH&S has developed this webpage and the document Anesthetic Gases: Safe Use Guidelines to help users of anesthetic gases understand the potential health effects from exposure and provide guidance in minimizing potential exposures.

Potential exposure to WAGs at UW could occur in the following settings:

  • UW Medicine operating rooms or other clinical applications with anesthesia
  • School of Dentistry facilities and UW Medicine-affiliated dental clinics
  • Department of Comparative Medicine (DCM) facilities (vivaria)
  • Washington National Primate Research Center (WANPRC) facilities
  • Research laboratories doing work with animals


What you can do to stay safe

  • Know what you are working with
  • Follow the procedures for safe handling and use of anesthetic gases and liquids
  • Ensure good ventilation and proper functioning and use of scavenging systems
  • Know signs and symptoms of exposure
  • If unsure, ask for help
  • Contact EH&S if needed

Services available

EH&S provides the following services:

  • Consultation about exposure concerns to anesthetic gases
  • Anesthetic gas/vapor spill advice
  • Air monitoring for anesthetic gases


Call EH&S at 206.221.7770 to talk about exposure concerns to anesthetic gases.

Call EH&S for spill advice at 206.543.0467.

Call EH&S at 206.221.7770 for more information or to request air monitoring for anesthetic gases.

Frequently asked questions


Environmental Health & Safety Contact

(206) 543-7262