Body
Title
Standard Operating Procedure for Isoflurane
EHS SOP #: 003
Version No.: 2.0
Supercedes: 1.0
Purpose
Isoflurane is a halogenated anesthetic gas commonly used in University animal research facilities and individual laboratories. This document establishes procedures for the safe handling and use of 1-chloro-2,2,2-trifluoroethyl difluoromethyl ether (CAS# 26675-46-7), commonly known as isoflurane or Forane®.
Health Effects
Isoflurane is a halogenated hydrocarbon that is a clear, colorless volatile liquid at standard temperature and pressure with a mild ether-like odor. It is known to cause serious eye irritation and human exposure to waste anesthetic gases has been associated with reproductive effects.
Signs of acute exposure
Nausea, vomiting, nose/throat/respiratory irritation, headache, dizziness, drowsiness, and skin irritation.
Signs of chronic exposure
Hypotension (low blood pressure), tachycardia (increased heart rate), respiratory depression, elevated blood glucose. liver/kidney disease, cancer, sterility, miscarriages, and birth defects in offspring.
Regulatory Limits
The Federal Occupational Safety and Health Administration (OSHA) do not have a Permissible Exposure Limit (PEL) for isoflurane. As of November 2022, the National Institute of Occupational Safety and Health (NIOSH) does not have a Recommended Exposure Limit (REL) for isoflurane (EPHB Report No. 2022-DFSE-822) and the American Conference of Governmental Industrial Hygienists (ACGIH) guidelines recommend an 8-hour Threshold Limit Value (TLV) of 50 ppm for exposure to isoflurane.
Air monitoring
- Area monitoring can be requested to assess potential exposures in the general laboratory work area. The monitoring is performed using a direct read instrument to give concentrations in room during surgeries or other procedures.
- Personal monitoring can be requested to determine potential exposures for individual employees who work with isoflurane. The monitoring is performed using a passive dosimeter that the employee wears in their breathing zone to quantify potential exposure.
- Exposure monitoring can be requested by contacting Environment, Health & Safety (EHS) at 919-962-5507 or chemsafety@ehs.unc.edu.
Requirements
Based on the risk associated with the use of waste anesthetic gases the safety procedures outlined below are required by all research staff when working with isoflurane.
Administrative Controls
- Institutional Animal Care and Use Committee (IACUC) protocols that include isoflurane should reference this SOP to verify that the standard operating procedures are being followed.
- Anyone who handles isoflurane is required to review this SOP and the attached Safety Data Sheet (SDS) prior to work.
Engineering Controls
- Isoflurane must be used in a well-ventilated room from which there is no recirculation of exhaust air.
- Active scavenging is optimal for scavenging waste gas and can include any of the following:
- Delivery of anesthetic inside a certified chemical fume hood or ducted biological safety cabinet (BSC). Use of the “drop method” should always be done using this method unless air monitoring has verified exposure levels below TLV.
- Connection of vaporizer and/or induction box exhaust hose into a certified chemical fume hood or ducted BSC.
- Connection of vaporizer and/or induction box exhaust hose to house vacuum.
- Passive scavenging can be used safely if specific procedures are followed. Passive scavenging relies on the positive pressure from the anesthetic gas delivery system and/or the exhalation effort of the animal to drive contaminated exhaled air through a specially designed activated carbon charcoal filter (such as F/AIR). The charcoal canister will adsorb and remove the waste gas before being discharged back into the room. Charcoal canisters have a finite effective life span, which can be monitored by weight.
- The weight of each new canister should be recorded before its first use (See attachments for Anesthetic Gas Charcoal Canister Weight Tracking Form).
- Before each subsequent use, the weight should be checked and recorded. If the total increase is close to 50 g, it should be replaced, or monitored closely during use (weigh between animals).
- To function appropriately, the carbon canister must be at a level below that of the vaporizer and the carbon canister must be in an upright/vertical position, to assist passive scavenging.
- To ensure adequate air flow, the holes on the bottom (F/Air) or top of the canister (VaporGuard) must not be blocked.
Personal Protective Equipment (PPE)
- Nitrile gloves, a lab coat, and safety glasses.
- When in rodent barrier facilities, PPE use must be consistent with the facility policy.
Waste Disposal
- Unused solutions of isoflurane will be disposed of as a hazardous material through EHS.
- Spent canisters (F/Air or VaporGuard) should be placed in a sealed bag, labeled with an unwanted materials label, and an EHS online waste pick-up request should be completed.
- Do not accumulate multiple canisters in your lab.
Accidents or Injuries
Spill Procedures
- Do not attempt to clean-up if you feel unsure of your ability to do so or if you perceive the risk to be greater than normal laboratory operations.
- Small volumes of isoflurane evaporate readily at normal room temperatures, and may dissipate before any attempts to clean up or collect the liquid are initiated. If a small spill occurs rapidly absorb any liquid with absorbent pads or paper towels and place in chemical fume hood for safe evaporation.
- If a large spill occurs notify others in the area and evacuate room immediately. Contact EHS (919-962-5507) during working hours and 911 if after hours.
Contact Information
Policy Contact
Environment, Health & Safety
1120 Estes Drive
Campus Box #1650
Chapel Hill, NC 27599-1650
Phone: 919-962-5507