Chemical Hazards: Health and Safety Practices Survey of Healthcare Workers

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Anesthetic gases (in medical settings)

Here you will learn what we found regarding waste anesthetic gases and best practices for minimizing exposure.


One of the principal goals of general anesthesia is to prevent patients from feeling pain during surgery. Halogenated anesthetics, such as sevoflurane and desflurane, are typically administered in combination with nitrous oxide to produce surgical levels of anesthesia. Anesthetic gases and vapors that leak into the surrounding room are considered waste anesthetic gases (WAGs). More than 250,000 healthcare workers may be exposed to WAGs and are at risk of developing adverse health effects.

Acute exposure to halogenated anesthetics can cause1:

  • Headache
  • Drowsiness
  • Difficulties with judgement and coordination

Chronic halogenated anesthetics exposure has been linked adverse reproductive effects and cancer2, although some studies report no adverse health effects form long-term exposure to low concentrations.3

Acute exposure to nitrous oxide can cause4:

  • Lightheadedness
  • Shortness of breath

Chronic nitrous oxide exposure in healthcare workers has been linked to4,5:

  • Reduced fertility
  • Spontaneous abortion
  • Neurologic disease
  • Renal and liver disease

This study was conducted to assess adherence to best practices for minimizing exposure to WAGs in medical (i.e., non-dental) procedures. The anesthetic gases survey module was mostly completed by physician anesthesiologists, nurse anesthetists and anesthesiologist assistants who reported administering them in the 7 days prior to the survey. We found that use of scavenging systems was nearly universal; however, adherence to other best practices was lacking which increased exposure risk. Both employers and healthcare workers share responsibility for adhering to best practices to minimize exposure to WAGs.

Best practices and study findings

What we found What employers/employees should do
3% of respondents reported that they did not always use a waste gas scavenging system when they administered anesthetic gases to patients. Use anesthesia machines with scavenging systems; be aware that older machines may not be equipped with such systems.1,2
17% of respondents with pediatric patients, and 6% of respondents with adult patients reported often using high flow anesthesia. Use closed-system or low flow anesthesia instead of high flow anesthesia when administering anesthetic gases to patients, when practicable.1,2
35% of respondents with pediatric patients and 14% of respondents with adult patients started anesthetic gas flow BEFORE delivery mask or airway mask was applied to patient. Start anesthetic gas flow AFTER delivery mask or airway mask is applied to patient.2
17% of respondents who filled vaporizers used a funnel-fill (i.e., open-air) system instead of a key-filler or closed-system device. Use a key-filler or other closed-system device when filling anesthesia vaporizers to minimize exposure to halogenated anesthetics from spills and vaporization.1,6,7
18% of respondents said they never received training and, of those who received training, 81% said that it was more than 12 months ago. Provide initial and annual refresher training on the hazards and appropriate methods to minimize exposure to anesthetic gases.1,2
19% of respondents said that employer safe handling procedures were unavailable. Make available to employees safe handling procedures for anesthetic gases.1


1 NIOSH. Waste anesthetic gases: occupational hazards in hospitalspdf icon.

2 OSHA. Anesthetic gases: Guidelines for workplace exposuresexternal icon.

3 Tannenbaum, T.N., and R.J. Goldberg: Exposure to Anesthetic Gases and Reproductive Outcome.external icon J Occ Med. 27:659-668 (1985).

4 New Jersey Hazardous Substance Fact Sheet: Nitrous Oxidepdf iconexternal icon.

5 NIOSH. Controlling exposures to nitrous oxide during anesthetic administration.

6 Berry A, McGregor DG, Baden JM, et al. [1999] Waste anesthetic gases – Information for management in anesthetizing areas and the post anesthesia care unit (PACU). American Society of Anesthesiologists, Park Ridge, IL

7 AANA Management of waste anesthetic gasespdf iconexternal icon.

Survey and report

To request a copy of this survey, please email

Journal articleexternal icon

(The free full text article will be available in Pub Med Centralexternal icon one year after the article has been published)

Page last reviewed: March 30, 2017