Control of nitrous oxide in dental operatories

"Commercially available scavenging systems for the control of nitrous- oxide (10024972) in dental operatories were evaluated in the field and in the laboratory. The field study sites included two pediatric dental facilities, an oral surgical clinic, and a dental clinic for the developmentally disabled. Sampling methods employed to gather data included personal and area sampling, real time nitrous-oxide sampling, video recording and documentation of work practices and infrared thermography. None of the scavenging systems were found to be adequate to control nitrous-oxide exposures. Tests were conducted in the laboratory and the field to evaluate two new local exhaust systems intended to control patient mouth emissions of nitrous-oxide. Face mask leakage was the primary cause of emissions. The use of exhaust systems placed on the chin or chest, or in the mouth captured mouth emissions. The authors conclude that it is possible to control nitrous-oxide levels to the NIOSH recommended exposure limit of 25 parts per million or lower when engineering controls; proper nitrous-oxide equipment maintenance; good work practices; and effective local, auxiliary and general ventilation controls are in place. The authors recommend that the use of nitrous-oxide be reduced, and that scavenging systems, ventilation, work practices, and equipment maintenance be used to control exposures." - NIOSHTIC-2James D. McGlothlin, Keith G. Crouch, R. Leroy Mickelsen."September 1994.""Report no. ECTB 166-04"--T.p. verso.Includes bibliographical references