Monitoring of occupational exposure to nitrous oxide.

The occupational exposure of operating room personnel to nitrous oxide was investigated by using multiple spot sampling, integrated personal sampling and end-tidal sampling in an operating room which had no ventilation system. The effect of passive scavenging on occupational exposure was determined. The study showed that all three methods to determine occupational exposure can yield representative time-weighted exposure patterns. However, the integrated personal sampling was considered the preferable method as it involved considerable saving of time and labour compared with taking and analyzing multiple end-tidal and spot samples. Passive scavenging of waste anaesthetic gases led to a three-fold to six-fold reduction of exposure of operating room personnel to nitrous oxide.