A Survey of Nitrous Oxide Levels in Dental Offices

Abstract

The nitrous oxide (N₂O) levels in 23 dental offices located in Philadelphia and surrounding suburbs were measured during an 8-hr working day using an infrared spectrophotometer. Results indicate that high concentrations of N₂O exist in the dental workplace and exceed NIOSH recommended values by over 40%. Mean ambient N₂O levels for all 23 dental offices was 35.7 ppm. There was no significant difference in the concentration of N₂O in small vs. larger dental offices. However, individuals in the large offices were exposed to high levels of the gas for shorter time periods. While only 4 of the 23 dental offices possessed scavenging equipment, scavenging systems appeared to make no significant difference in ambient N₂O levels in the dental workplace.