title: Isoflurane waste anesthetic gas concentrations associated with the open-drop method.
abstract: The open-drop technique is used frequently for anesthetic delivery to small rodents. Operator exposure to waste anesthetic gas (WAG) is a potential occupational hazard if this method is used without WAG scavenging. This study was conducted to determine whether administration of isoflurane by the open-drop technique without exposure controls generates significant WAG concentrations. We placed 0.1, 0.2, or 0.3 ml of liquid isoflurane into screw-top 500 or 1000 ml glass jars. WAG concentration was measured at the opening of the container and 20 and 40 cm from the opening, a distance at which users likely would operate, at 1, 2, or 3 min WAG was measured by using a portable infrared gas analyzer. Mean WAG concentrations at the vessel opening were as high as 662 +/- 168 ppm with a 500 ml jar and 122 +/- 87 ppm with a 1000 ml jar. At operator levels, WAG concentrations were always at or near 0 ppm. For measurements made at the vessel opening, time was the only factor that significantly affected WAG concentration when using the 500 ml jar. Neither time nor liquid volume were significant factors when using 1000 ml jar. At all liquid volumes and time points, the WAG concentration associated with using the 500 ml container was marginally to significantly greater than that for the 1000 ml jar.
authors.affiliation: Division of Animal Resources, Emory University, Atlanta, Georgia, USA. dtaylor@dar.emory.edu
authors.forename: Douglas K
authors.initials: DK
authors.lastname: Taylor
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Mook
mesh_terms: D000395:Air Pollutants, Occupational / Q000009:adverse effects / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis*; D000758:Anesthesia / Q000009:adverse effects / Q000379:methods*; D018685:Anesthetics, Inhalation / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring; D006256:Hazardous Waste / Q000009:adverse effects / Q000032:analysis*; D006801:Humans; D007530:Isoflurane / Q000009:adverse effects / Q000032:analysis*; D007756:Laboratory Animal Science / Q000379:methods; D016273:Occupational Exposure / Q000517:prevention & control*
chemical_list: D000395:Air Pollutants, Occupational; D018685:Anesthetics, Inhalation; D006256:Hazardous Waste; D007530:Isoflurane