Kathy Heivilin, BS, CPIA, RBP
IACUC Vice Chair, Senior IACUC Manager
UM Biosafety Officer
Anesthetic Waste Gas
Adopted: February 9, 2010
Last Review Date: October 10, 2017
The purpose of this policy is to protect the health of persons working with or near anesthetic gases used to sedate or euthanize animals at the University of Montana. Volatile anesthetic waste gases should be minimized through training in anesthetic administration, using the smallest amount of anesthesia necessary, maintaining anesthetic equipment in proper working order, scavenging anesthetic waste gases, and monitoring worker exposure.
A. Approved Inhalant Anesthetic Agents
euthanasia with proper approval from the Institutional Animal Care and Use
Its primary indication in veterinary medicine is as an adjunct to
the area must be provided by the principal investigator (PI), Attending
Veterinarian, Laboratory Animal Resources (LAR) staff, or a trained
vaporizers at their lowest settings necessary for maintaining adequate anesthesia,
use of scavenging equipment, and animal monitoring.
C. Equipment Maintenance
center every other year. In the years between the exchange, vaporizers
or the date of next needed maintenance.
D. Waste Gas Scavenging
through a house vacuum, passively using a charcoal canister, or actively
masks should fit snugly.
gauze with anesthetic dripped on the gauze), it must be performed in a
the jar at arm’s length when opening, and using a jar/container with a volume of
500-1000 ml. Care should be taken to ensure that the liquid anesthetic does
E. Worker Exposure Monitoring
use 2 ppm as an institutional recommended exposure limit (REL). Monitoring
Administration has published a document entitled "Anesthetic Gases: Guidelines
for Workplace Exposures" at
"In 1997, the National Institute for Occupational Safety and Health (NIOSH) … recommended that no worker should be exposed at ceiling concentrations greater than 2 ppm of any halogenated anesthetic agent over a sampling period not to exceed one hour (NIOSH 1977). In 1989, the American Conference of Governmental Industrial Hygienists (ACGIH) assigned a threshold limit value-time-weighted average (TLV-TWA) for . . . halothane and enflurane, and are 50 ppm and 75 ppm, respectively. No NIOSH recommended exposure limits (REL) exist for the three most currently used anesthetics (isoflurane, desflurane, and sevoflurane). The levels of risk for isoflurane, desflurane, and sevoflurane have not been established. Since there are limited data, occupational exposure limits for these agents have not been determined. Therefore, until more information is available, it is prudent to attempt to minimize occupational exposure to these as with all anesthetic agents."