July 1998
by Amy Canavino
All chemical fume hoods are designed to draw air into the hood and away from you, and to serve as exhaust ventilation for the laboratory.
Using the hood as a storage space is the most common misuse of fume hoods. Do not use a fume hood for storing large equipment. Also, storing chemicals in the hood clutters it and interferes with the air being pulled into the lower baffle opening along the back wall of the hood.
Anything in the chamber creates turbulence, and too much turbulence can cause back flow of air out of the hood and into your breathing area.
To ensure adequate exhausting of fumes, make sure that there are no objects blocking the baffle, air foil, or bypass.
Walk-in hoods are rare at NU but ORS uses 2 in its waste facilities. Unlike the typical hood, these units are designed for storage, assuming the hood operates properly. These hoods are tested with smoke bombs to confirm acceptable air flow patterns and containment.