9.2 Chemical Fume Hoods

A fume hood is a local exhaust device whose primary purpose is to protect laboratory workers from hazards of airborne chemical contaminants. The secondary purpose is to protect people and property against small fires and explosions. The fume hood must be used properly to allow it to function properly and remove contaminants from the breathing area of the user.

  • Use chemicals in the hood that may generate contaminants near or above exposure limits.
  • Do not have sources of ignition inside the hood when flammable liquids or gases are present.
  • Visually inspect the device (and flow monitor) daily or before each use.
  • Keep all items 6 inches back from the front edge of the hood to avoid blocking the airflow path.
  • Keep slot openings at the back of the hood free from blockage with large objects or numerous containers.
  • Elevate large objects 2 inches off the floor of the hood so air can pass under the object and out the back slots in the hood.
  • Close the sash when the hood is not in use
  • During hood use, lower the sash to the sash arrow sticker, below the chin and more if possible. Lower and use the sash as a safety shield when working with reactive materials or materials that may splatter.
  • Do not store chemicals in hoods.