Nitrous oxide may be used to alleviate dental anxiety and to diminish or eliminate dental pain. The benefit of nitrous oxide sedation is a cooperative and satisfied patient. By reducing the patient's perception of pain it allows them to relax and cooperate during dental procedures. However, the dental surgery personnel, chronically exposed to N₂O, are at serious risk. The chronic effects of occupational exposure to nitrous oxide have long been the subject of debate. Safety standards have been established in the United States and Europe since many years. The potential detrimental action on the reproductive, neurological, haematological, hepatic and renal systems, plus the possibility of increased cancer risk have been the subject of active research, although absolute occupational effects are still uncertain. To provide a safer work-place for those at risk of exposure to waste anesthetic gases, preventive measures are recommended.