Laboratory Fume Hood Standards

Laboratory fume hoods are used to prevent harmful exposure to hazardous substances. Hazardous substances are explosive, flammable, poisonous, an irritant, or otherwise harmful and likely to cause injury or illness.

All research experiments involving chemicals should always be performed in a laboratory fume hood.

Measurement Procedures As Follows:

1. Start with the movable sash fully opened.

2. Average six separate measurements using a velometer.

3. 100 Linear Feet Per Minute (LFPM) average face velocity required.

4. No single measurement below 70 Linear Feet Per Minute (LFPM).

5. The average face velocity should not go above 150 LFPM.

6. If below 100 LFPM average or 70 LFPM single measurement set sash at 18 inches and repeat step 5.

7. If below 100 LFPM average or 70 LFPM single measurement set sash at 12 inches and repeat step 5.

8. The sash shall be marked to show the maximum opening at which the hood face velocity will meet the requirements.

9. Any hood failing to meet average face velocity requirements of 100 LFPM at a minimum 12-inch sash opening is considered deficient in airflow and shall be posted with placards prohibiting use of hazardous substances within the hood. Physical Plant must be notified to repair the deficient hood.

10. Each fume hood is required to be tested on an annual basis.

• Mechanical ventilation shall remain in operation at all times when hoods are in use and for a sufficient time thereafter to clear hoods of airborne substances.
• A means shall be provided at the hood to continuously indicate that air is flowing into the exhaust system during operation.

High Hazard Hoods – For use of particularly hazardous substances such as carcinogens, reproductive toxins, and compounds with a high degree of acute toxicity. These hoods should have a minimum velocity of 125 LFPM.