Chemical fume hoods are important laboratory equipment, the first line of defense against exposure to hazardous chemicals.  EH&S personnel check fume hoods at least once annually.  However, lab personnel may request more frequent performance checks, particularly when the fan/motor is serviced.  Where present, face velocity monitors are recalibrated at the same time.  When a fume hood is suspected of breaking down, call EH&S at (212)854-8749 (MS) or (212)305-6780 (CUMC) to coordinate with Area Management for repairs.

Proper Use of Fume Hoods

Please post near fume hood(s)

1. Prior to fume hood use, become familiar with the locations of the nearest exit, emergency shower, eye-wash station and fire extinguisher. Ensure emergency equipment remains unobstructed at all times.

2. Wear personal protective equipment (e.g. goggles, gloves and lab coats). No fume hood can prevent dermal absorption. Fume hoods are by no means a replacement for protective wear and good laboratory practices.

3. Keep experimental apparatus, and sources of contaminants with the hood, at a distance of at least six inches behind the sash opening to avoid disruption of airflow.

4. Avoid cross drafts at the face of the hood, as these will disturb the direction of air flow. Even someone moving quickly across in front of the hood will create sufficient current to cause turbulent activity which might bring the air contaminants into your breathing zone.

5. Keep the hood uncluttered; the more cluttered a hood, the more air flow disturbances. Try not to store chemicals in the hood. Storage of materials/equipment in the hood should be kept to a minimum. No peroxide-forming compounds, e.g. ether, may be stored in a hood.

6. Where open flame is used, no flammable liquids may be kept in the hood. Flammable liquids should be stored in a safety cabinet when not in immediate use.

7. The vertical sliding sash is used to serve as a physical barrier in the event of chemical splashes within the hood. For this reason, the sash should be kept below eye level where a face velocity of 80-120 fpm is achieved. In addition, the sash must be positioned below breathing zone height to protect the user in the event that hazardous vapors escape the fume hood.

8. Keep your head outside the face of the hood. Keep the sash closed when the hood is not attended.

9. The work surface of the hood should be thoroughly cleaned after completion of all experiments and immediately following use of any chemicals.

10. Remain alert to changes in airflow and be familiar with appropriate emergency procedures in the event of fume hood failure. Report hood failure to the laboratory supervisor and/or Facilities Management for repair.

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Engineering Controls

Equipment Use

Laboratory hoods control exposure to toxic, unpleasant, and/or flammable vapors. They protect users from implosions but not from explosions. If it is essential to carry out a process that could result in an explosion, conduct such work behind sturdy barriers that are designed and build for the purpose. Regular hoods are not strong enough to endure the force of any but the mildest of explosion.

Do not alter the size of the vent openings in the rear and ceiling of a hood and never block exhaust ports or slots in the rear wall and ceiling of the hood. Remember that the air in inside a hood can change when a window or door is opened and even by a change of position of the worker at the hood. Hence, when you are at hood, keep the sash closed, or open it only the minimum amount necessary.

NEVER place your head inside the hood.

If ever someone feels that a hood they are using is not working properly, please contact EH&S at (212)854-8749 (MS) or (212)305-6780 (CUMC). Give the location of the hood.

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