NIOSH Study Finds Widespread Use of Scavenging Systems to Control Waste Anesthetic Gases During Medical Procedures, but Other Recommended Controls Lacking

October 5, 2016
NIOSH Update:

Contact: Nura Sadeghpour (202) 245-0673

A new article from the National Institute for Occupational Safety and Health (NIOSH) found that scavenging systems, equipment used to prevent waste anesthetic gases from escaping into the operating room, are widely used but other recommended practices to minimize exposure are not always followed. This study was published in the October 2016 issue of the Journal of Occupational and Environmental Hygiene and is currently available online.

Results are derived from the 2011 NIOSH Health and Safety Practices Survey of Healthcare Workers, the largest federally-sponsored survey of healthcare workers in the U.S. which addresses safety and health practices relative to use of hazardous chemicals. This national survey is the first to examine self-reported use of scavenging systems and other controls to minimize exposure to waste anesthetic gases among anesthesia care providers. Members of professional practice organizations representing physician anesthesiologists, nurse anesthetists and anesthesiologist assistants were invited to participate in the survey. The survey was completed by nearly 3,000 anesthesia care providers who administered inhaled anesthetics in the seven days prior to the survey.

Working in hospitals and outpatient surgical centers, respondents reported that they most often administered sevoflurane and, to a lesser extent desflurane and isoflurane, usually in combination with nitrous oxide. Use of anesthesia machines equipped with scavenging systems was nearly universal. However, adherence to other recommended practices were lacking by varying degrees and differed among those administering anesthetics to pediatric or adult patients. The following describes examples of practices which may increase exposure risk:

  • 3% did not always use anesthesia machines equipped with a waste gas scavenging system
  • 35% started anesthetic gas flow before mask was applied to pediatric patient and 14% did the same for adult patients.
  • 19% reported safe handling procedures were unavailable.
  • 18% never received training on safe handling of anesthetic gases.
  • 17% used a funnel-fill (open-air) system instead of a key-filler or other closed system to fill anesthesia vaporizers.
  • 17% used high (fresh gas) flow anesthesia only for pediatric patients and 6% did the same for adult patients.
  • 5% did not routinely check anesthesia equipment for leaks.

When precautionary practices are not followed, anesthesia care providers and bystanders are at risk of exposure. Ensuring proper precautionary measures are utilized requires diligence on the part of both employers and healthcare workers. Employers need to ensure that anesthesia care providers are initially and periodically trained; safe-handling procedures reflecting recommended practices are in place and support for their implementation is understood; anesthesia machines with scavenging systems are used (including regular inspection of anesthesia delivery equipment for leaks, periodic air and exposure monitoring, and prompt elimination of spills and leaks); and medical surveillance, exposure monitoring and other administrative controls are in place. Anesthesia care providers can seek out training, understand and follow facility procedures, ask questions, and report any safety concerns.

The findings from this self-reported survey are expected to help NIOSH, partners, employers and healthcare workers better understand current health and safety practices relative to working with hazardous chemical agents and identify gaps in current knowledge about those practices. To access the current article online, visit: icon.

To learn more about healthcare safety and health, visit: More information can be found at

NIOSH is the federal institute that conducts research and makes recommendations for preventing work-related injuries, illnesses and deaths.

Page last reviewed: October 5, 2016