In 1994, the National Institute for Occupational Safety and Health (NIOSH) issued a warning to the hundreds of thousands of medical, dental, and veterinary professionals who work with nitrous oxide (N2O). The Institute warned that even with preventive measures such as scavenging systems in place these workers may be at risk for serious health effects due to their exposure.
N2O, commonly called laughing gas, is an anesthetic agent used in operating rooms. Workers are exposed to N2O while administering the anesthetic gas to patients. To protect workers from the health risks associated with N2O, operating rooms are often equipped with scavenging systems that vent unused and exhaled gas away from the work area. Research has shown that these systems can significantly reduce the risk of impaired fertility among female dental assistants exposed to N2O.
However, a NIOSH Alert reports that even with scavenging systems in place, Institute researchers measured N2O exposures as high as 12 times the NIOSH recommended limit in hospital operating rooms and more than 40 times the NIOSH recommended limit in dental operating rooms. The report clearly demonstrates that simply using a system is not sufficient--it must be continuously monitored and maintained to effectively reduce exposure to N2O.
Several human studies have shown that occupational exposure to N2O may cause reduced fertility, spontaneous abortions, and neurologic, renal, and liver disease as well as documented decreases in mental performance, audiovisual ability, and manual dexterity. Moreover, animal studies have shown that exposure to N2O during gestation can produce adverse health effects in offspring.
The NIOSH Alert, Request for Assistance in Controlling Exposures to Nitrous Oxide During Anesthetic Administration, warns workers of the hazards of N2O exposure and provides prevention measures. A summary of the guidelines for controlling exposure to N2O is provided on the following page. Although properly operating scavenging systems have been shown to reduce N2O concentrations by more than 70%, simply having a scavenging system in place is not enough. Workers and employers must ensure that systems and equipment are properly operated, inspected, and maintained. NIOSH urgently requests your assistance in informing all workers of the hazards they face if exposed to N2O at their workplace.