Waste anesthetic gases (WAGs) can be produced when anesthetic gas and vapors leak into the surrounding room during medical or research procedures. Waste anesthetic gases can create health effects to humans. MSU researchers and clinicians must be aware of the potential risks of WAGs and take appropriate precautions to reduce potential exposures to employees and students.
The National Institute for Occupational Safety and Health (NIOSH) (2007) states that “exposure to high concentrations of waste anesthetic gases - even for a short time - may cause the following health effects: headache, irritability, fatigue, nausea, drowsiness, difficulties with judgment and coordination, liver and kidney disease.
NIOSH (2007) continues: “Although some studies report no adverse health effects from long-term exposure to low concentrations of waste anesthetic gases, several studies have linked such exposure to miscarriages, genetic damage, and cancer among operating-room workers. Studies have also reported miscarriages in the spouses of exposed workers and birth defects in their offspring.”
NIOSH later reports that “Some studies have documented adverse health effects (e.g., headaches, fatigue, irritability, birth defects, miscarriages, liver and kidney disease, cancer) from excessive exposure to anesthetic gases. These health effects were mainly noted for older anesthetics (e.g., trichloroethylene, methoxyfluorane) that are no longer commonly in use. Studies are inconclusive on the potential health effects from occupational exposure to some of the newer anesthetics, such as isoflurane.
MSU researchers, clinicians and students can be exposed to WAGs by:
A safe human exposure concentration for any halogenated anesthetic agent is less than 50 parts per million (ppm) threshold limit value (TLV), or 25 ppm of nitrous oxide over an 8-hour time weighted average (TWA).
When nitrous oxide is used in combination with halogenated gas, control of nitrous oxide to 25 ppm during anesthesia should limit concentrations of the halogenated gases to less than 0.5ppm. Charcoal filters/canisters will not work with nitrous oxide. Active scavenging is required.
General building ventilation systems cannot not be relied upon to control WAGs. The following engineering controls should be used to control human exposure – preference in this order:
The following are recommended work practices for reducing human exposure to Waste Anesthetic Gases:
MSU researchers and clinicians should not attempt to repair malfunctioning anesthetic machines. The designated and qualified employee or certified contractor should perform routine maintenance program to check for and fix leaking equipment and to assure that ventilation requirements are met.
Users must contact MSU EHS for air monitoring and evaluation if they suspect human exposure to WAGs.
Air monitoring will be performed on both worst case and routine exposures for each job class.
Sample results of the air monitoring along with any necessary exposure reduction measures will be reported to the supervisor and also shared with the monitored worker(s).
Acute health symptoms: MSU researchers, clinicians or students with acute health symptoms of WAG exposure should call 911 immediately for assistance.
Chronic health symptoms: MSU researcher, clinicians or employee with symptoms of possible over-exposures to WAGs should contact EHS and the University Occupational Health Physician for a clinical consultation.
When filling the vaporizer, wear chemical resistant gloves (not latex), safety glasses and an apron or lab coat.
Supervisors are responsible to assure that workers who may be potentially exposed to waste anesthetic gases are trained to recognize, understand and reduce health and safety risks of exposure to WAGs. This training should include all of the contents of this document.
For dry, empty anesthetic gas containers that are glass, deface the label and dispose in the broken glass box.
Expired or unwanted anesthetic gas containers and used charcoal canisters must be disposed of as hazardous waste; place the container in a ziplock bag and request a hazardous waste pickup via the MSU EHS website.
OSHA: Anesthetic Gases: Guidelines for Workplace Exposures
https://www.osha.gov/dts/osta/anestheticgases/index.html
NIOSH 2007: Waste Anesthetic Gases–Occupational Hazards in Hospitals
https://www.cdc.gov/niosh/docs/2007-151/default.html
NIOSH 2017: Reproductive Health and the Workplace: Anesthetic Gases