REPRODUCTIVE HEALTH AND THE WORKPLACE

Anesthetic Gases

Working with anesthetic gases could increase your chances of having a miscarriage if the gases are not properly controlled. Here, you can learn more about anesthetic gases and what you can do to reduce your exposure for a healthier pregnancy.

What are anesthetic gases?

  • Anesthetic gases are used to keep patients unconscious during surgery.
  • “Waste anesthetic gases” are small amounts of anesthetic gases that leak from the patient’s breathing mask into the air of operating or recovery rooms. These gases may also be exhaled by patients recovering from anesthesia.
  • Names of anesthetic gases include: nitrous oxide, halothane, enflurane, isoflurane, desflurane, sevoflurane, and methoxyflurane (no longer used in the United States).

Why should I be concerned about exposure?

  • We know that people who have been exposed to waste anesthetic gases have an increased risk of miscarriage. Hospitals are better now at preventing anesthetic gases from leaking into operating rooms during surgery, which reduces the exposure of workers. Therefore, we think the risk of miscarriage is lower in most of today’s operating rooms than it used to be.
  • If you work with children or animals, it may be difficult to control the leaking from the mask because the patient may move around a lot.

Who is exposed to anesthetic gases?

  • Anyone working in an operating room or recovery room with an anesthetized patient (human or animal) might be exposed to anesthetic gases. This includes anesthesiologists, dentists, veterinarians, nurse anesthetists, operating-room nurses, operating-room technicians, other operating-room personnel, recovery-room nurses, other recovery-room personnel, and surgeons.
  • Workers are most likely to be exposed to waste anesthetic gases in operating rooms with no automatic ventilation or scavenging systems, operating rooms where these systems are in poor condition, or recovery rooms where gases exhaled by recovering patients are not properly vented or scavenged.
  • Workers may be exposed when leaks occur in the anesthetic breathing circuit, when anesthetic gases escape during hookup and disconnection of the system, or when anesthetic gas seeps over the lip of the patient’s mask.

What is not known?

  • We don’t know what causes most miscarriages. If you work with anesthetic gases and have a miscarriage, we often can’t tell if it was caused by working with anesthetic gases or if it was caused by something else.
  • We don’t know what levels of anesthetic gases are safe during pregnancy. Try to reduce or eliminate your exposure as much as possible.

What can I do to reduce or eliminate exposure?

  • Scavenger systems, devices used to gather and remove waste anesthetic gases from treatment rooms, must be maintained and monitored to make sure they are working properly.
  • Pregnant workers may consider talking to their employers to avoid exposure to these gases during pregnancy.
  • If exposure cannot be avoided during pregnancy, respirators can be worn to reduce the amount of certain chemicals that workers breathe in. Charcoal masks or surgical masks will not protect you from these chemicals. To be effective, respirators must be used correctly. Learn more about respirators and pregnancy. Talk to your doctor and your employer if you think you might need to use a respirator.  
  • Follow the recommendations in the NIOSH guidance on waste anesthetic gases to reduce or eliminate your exposure as much as possible. Share this guidance with your employer to make sure they are following the most recent guidance for protecting workers from exposure to anesthetic gases.
Page last reviewed: April 20, 2017