Nitrous Oxide Safety for Pregnant Dental Staff and Patients

Guidelines for Practice Success | Managing Pregnancy | Business Operations

Many dental practices use nitrous oxide to help manage patient’s anxiety and discomfort during a variety of procedures. While nitrous oxide can be beneficial in the delivery of treatment, pregnant women should avoid exposure due to the possibility that it can harm the developing fetus.

Consult your employer’s employee handbook or policy manual to determine what policies relate to you as a pregnant employee and regarding issues like the use of nitrous oxide. Talk to your manager, your Human Resources representative, or the practice’s office manager/administrator if you have questions about any relevant policies or wish to request accommodations or protective equipment. Be aware that you may be asked to provide a statement from your physician regarding any request.

One best practice for protecting you and your baby is educating yourself about the potential risks of exposure to nitrous oxide and taking steps to mitigate them. A few valuable resources include:

  • Reviewing the National Institute for Occupational Safety and Health’s (NIOSH) Control of Nitrous Oxide in Dental Operatories publication. According to that resource:
    • 25 ppm is the recommended exposure limit for nitrous oxide concentrations in the dental setting during analgesia administration.
    • Recommended methods for controlling exposure include:
      • System maintenance to include the proper inspection, maintenance, and immediate repair of any leaks.
      • Ventilation, to include the use of:
        • Scavenging systems to direct gas from the patient’s mask to the outdoors. Do not allow gas from the patient’s mask to flow into the room’s ventilation system.
        • Room ventilation that uses clean outdoor air for dental operatory ventilation whenever possible. Maintain sufficient space between the supply and exhaust vents to allow for good mixing.
        • Auxiliary exhaust ventilation that captures excess nitrous oxide by placing a local exhaust hood near the patient’s mouth.
      • Work practices to include:
        • Using scavenging masks that fit patients properly.
        • Sedating patients prudently.
        • Monitoring air concentration of nitrous oxide to ensure that the system control of exposure is effective.
    • The publication also includes a NIOSH Technical Data Sheet that provides specific steps for controlling the release of nitrous oxide in the practice and tips for conducting periodic air sampling.
  • Reviewing nitrous oxide information and resources available through the American Dental Association’s (ADA) Science Institute. While not specific to concerns associated with pregnancy, these excerpted best practices recommended by the ADA Council on Scientific Affairs can keep nitrous oxide levels safe:
    • Equipping every nitrous oxide delivery system with a scavenging system.
    • Venting vacuum and ventilation exhaust fumes outside.
    • Testing pressure connections for leaks every day when the nitrous system is first turned on and each time a gas cylinder is changed.
    • Inspecting all system components before the first use of the day.
    • Ensuring the correct flow rate after the system has passed daily inspection.
    • Properly fitting each mask to each patient.
    • Encouraging patients to breathe through the nose and limit talking while nitrous oxide is in use.
    • Monitoring administration to watch for changes in the tidal volume of the reservoir bag and watching the vacuum pump flow rate.
    • Delivering 100% oxygen to the patient for five minutes after the procedure is over and before removing the mask.
    • Monitoring or assessing employees, especially those who work with the nitrous oxide delivery system, regularly by using either wearable personal badges or by placing an infrared spectrophotometer in the room.

An additional resource available from the National Institute for Occupational Safety and Health’s (NIOSH) is the agency’s article on Anesthetic Gases.


  • National Institute for Occupational Safety and Health’s (NIOSH) article on Anesthetic Gases