Flume Hood Operations



Fume hoods are a necessary piece of engineered equipment to protect users and occupants from possible chemical exposures. There are approximately 75 fume hoods on campus, located in Bill Hall, New London Hall, Hale Laboratory and Olin Science Center. These hoods are inspected and certified annually by the Director of EH&S.

Fume hood function and hygiene are among the inspection criteria. A certification sticker is present if your fume hood has been tested and certified as part of the annual hood certification program. If your fume hood does not have a current white certification sticker applied to the hood frame, please call EH&S so that it may be inspected. To maximize hood effectiveness and minimize personal exposure to toxic vapors or gases, fume hoods should be used in accordance with these operational guidelines:

  • Operate the hood at the proper sash height, as indicated on the EH&S certification sticker. Face velocities should be not less than 100 CFM, and the sash height has been calculated to this number.
  • Keep the sash lowered when not in use. When you are working in the hood, always keep the sash of the hood below your face.
  • Fume hoods must not be altered or modified. Doing so will interfere with airflow and could create a hazardous environment for laboratory occupants. Modified fume hoods will be removed from service until the hood is returned to its original condition..
  • Locate electrical devices such as variacs outside the hood, to avoid sparking that could ignite flammable reagents and/or solvents.
  • Do not block the hood's airflow. Place bulky equipment towards the rear of the hood and away from the side walls, and raise it about 2 inches off the surface with blocks or bricks. This will allow airflow around and under the equipment. Equipment placed near the hood face will cause significant variation in airflow. All equipment should be a minimum of 9-12 inches away from the hood face.
  • Hood sashes should be lowered to a position where they can provide protection from splashes, sprays and fires. Work as far inside the hood as possible (at least 4 to 6 inches from the front edge), with the sash face between you and task at hand.
  • Keep sash face clean and clear. To encourage use of sash as added protection against splashes, sprays, etc. keep sash face clean. If sash face must be blocked with paper for certain experiments, please take it down after the experiment is complete.
  • Do not use the hood as a storage cabinet for chemicals or equipment. Materials stored in fume hoods should be kept to a minimum and stored in a manner that will not interfere with airflow.
  • Do not use a hood for any function it was not designed for, such as perchloric acid and radioactive isotopes, etc. The generation of perchloric acid vapors requires specially designed fume hoods with wash-down systems designed to prevent the accumulation of explosive perchloric acid crystals.
  • Wear protective equipment! Fume hoods do not prevent accidents or chemical splashes. Personnel protective equipment (safety glasses, gloves, aprons, etc.) appropriate to the conditions must always be worn.
  • Close sash when finished with hood work or when leaving experiments or chemicals unattended! This simple procedure has contained many fires and explosions within a hood. In addition, closing the sash when not in use saves a TREMENDOUS amount of Energy! Be safe and green!