Waste Anesthetic Gas
This section has been reviewed and updated as needed: April 2012
Responding to the scientific literature indicating that there may be adverse health effects associated with exposure to waste anesthetic gases, UNC-CH Clinical Facilities and UNC Healthcare have established a program for the safe use of anesthetic gases that meets or exceeds the recommendations of occupational health advisory agencies (National Institute for Occupational Safety and Health and the American Society of Anesthesiologists) and complies with JCAHO accreditation criteria. UNC-CH and UNC Healthcare will use the NIOSH Recommended Exposure Limits (RELs) of 25 ppm for nitrous oxide and 2 ppm for halogenated agents when evaluating employee exposures. Desflurane, isoflurane and sevoflurane were not widely used when the REL was established and they were not among the halogenated agents specified by NIOSH in its recommendation. However, UNC-CH and UNC Healthcare will use the 2 ppm limit as a guide until OSHA, NIOSH, or another recognized authority establishes an occupational exposure limit specifically for desflurane, isoflurane and/or sevoflurane. NIOSH is currently reviewing public comments for this purpose.
UNC-CH Environment, Health and Safety Office and UNC Hospitals’ Environmental Health and Safety Department
The UNC-CH Environment, Health and Safety Office and the UNC Hospitals’ Environmental Health and Safety Department will be responsible for sampling and maintaining records on all air sampling and shall prepare and forward a written report of the sampling results to the appropriate department manager for distribution to the affected employees.
UNC-CH Facilities Services and Medical Engineering Department
The Medical Engineering Department has the responsibility for preventative maintenance on anesthetic equipment to assure that the equipment is working properly so as not to harm the patient or expose the employees to high levels of anesthetic waste gases.
Anesthesiology Department/Dental Clinic and All Other Departments Using Anesthetic Agents
These departments have the responsibility for work practice control. Work practices may contribute to 94-99% of the anesthetic waste gases released into the scavenged operating room air. Therefore, it is essential to use proper anesthetic techniques.
- All departments using anesthetic gases shall be responsible for providing annual anesthetic gas safety training to their affected employees.
- All departments using anesthetic gases shall maintain records on training sessions including dates, topics, and attendees. Copies of these records shall be forwarded to the UNC-CH Environment, Health and Safety Office and the UNC Hospitals’ Department of Environmental Health and Safety.
- All departments using anesthetic gases shall encourage employees in the proper use of work practices designed to reduce ambient waste anesthetic gases during the anesthesia administration period.
- The employee shall be responsible for using anesthetic gases in a manner consistent with the design of the machine and the scavenging system used.
- The employee shall ask their supervisor for assistance in the event of problems or difficulties.
Anesthesiologists, Residents and Certified Nurse Anesthetists are responsible for implementation and Medical Engineering is responsible for maintenance of equipment.
- Scavenging systems must be used with all anesthesia machines.
- Exhausts where anesthetic gases are vented must be separated from intakes in such a manner that prevents waste anesthetic gases from entering any ventilation intakes.
- Scavenging systems shall be checked for leakage at least quarterly by Medical Engineering and Environmental Health and Safety.
Medical Engineering and the Anesthesiology Technicians are responsible for maintaining the equipment.
- High-pressure systems shall be leak tested at least quarterly by Medical Engineering and Environmental Health and Safety.
- Low-pressure systems shall be tested with each use by the Anesthetist or Anesthesiologist.
Head walls/gas outlets
- High-pressure testing of the head walls/gas outlets shall be conducted at least annually (subset done quarterly) by Environmental Health and Safety.
- Environmental Health and Safety will notify Plant Engineering if there are leaks at the head walls/gas outlets and repairs are needed.
UNC-CH Environment, Health and Safety Office and the UNC Hospitals’ Environmental Health and Safety Department are responsible for implementation. Sampling will be conducted on both a quarterly and annual basis in the Operating Room and Dental Clinic by the UNC-CH Environment, Health and Safety Office and UNC Hospitals’ Environmental Health and Safety Department. Sampling will also be conducted whenever ventilation of anesthetic equipment or scavenging techniques are modified. Medical Engineering shall notify UNC-CH Environment, Health and Safety or UNC Hospitals’ Environmental Health and Safety to advise when ventilation of anesthetic equipment or scavenging techniques are modified.
- Personal sampling will be performed in the breathing zone of affected personnel during the anesthesia administration period using passive dosimeters and/or real time monitros.
- Other areas where patients are recovering after anesthetia administration, such as the Post Anesthesia Care Unit (PACU), will be monitored on an annual schedule.
- Area sampling will be accomplished through infrared analysis using the Miran 1BX or the SapphIRe. Anesthesia machines and scavenging systems will be checked for leaks using these instruments. When a leak is detected, Medical Engineering will be notified and the leaks shall be repaired immediately.
- Results of monitoring will be forwarded to department managers for sharing with effected employees within thirty- (30) day of receipt of the results and reviewed by the Personnel and Environmental Safety Subcommittee.
Plant Engineering should ensure that the minimum total air change rates in the OR will be strictly followed. NIOSH recommends at least 15 air exchanges per hour.
Product Labeling and Work Site Posting
All areas where there is a potential exposure to anesthetic gases shall be posted with a sign that reads:
(NAME OF AGENT)
CAUTION: HARMFUL IF INHALED CONTINUOUSLY
Use with adequate ventilation and/or scavenging equipment.
Warning labels for anesthetic gases must not be removed from the product.
- University Employees Occupational Health Clinic (UEOHC) and UNC Healthcare Occupational Health Service (OHS) provide counseling for employees, especially pregnant women, concerned about health effects related to occupational exposures including anesthetic gases. Employees desiring counseling should call UEOHC at 919-966-9119 or OHS at 919-966-4480 and make an appointment.
- Any employee who has problems or symptoms they feel are due to an occupational exposure to chemicals should fill out an incident report and be seen immediately in UEOHC or OHS.
It is the responsibility of the Anesthesiology, Medical Engineering, UNC-CH Environment, Health and Safety, and UNC Hospitals’ Environmental Health and Safety Departments to implement this policy.