2.1 Chemical Fume Hoods
Fume hoods and other capture devices are used to contain the release of toxic chemical vapors, fumes, and dusts. Bench top use of chemicals that present an inhalation hazard is strongly discouraged. Fume hoods are to be used when conducting new experiments with unknown consequences from reactions or when the potential for a fire exists.
To achieve optimum performance, the greatest personal protection and reduce energy usage when using a fume hood:
- Ensure the fume hood is working by checking the tell-tale (crepe paper hanging from hood sash) and air monitoring device if the hood is equipped with one. DO NOT use an improperly working fume hood.
- If the fume hood is not working properly, let other people in the lab know by hanging up a Do Not Use Sign on the hood.
- Work several inches inside the hood. This provides for the greatest amount of capture and removal of airborne contaminants. Also, do not place items on the airfoil or work with chemicals at the face of the hood.
- Do not block the baffles at the back of the hood. These allow for proper exhausting of contaminants from the hood.
- Keeping the hood sash lowered improves the performance of the fume hood by maintaining the internal vortex and containment. It also helps to conserve energy.
- Keep the fume hood sash closed all of the way whenever the fume hood is not being used. Shut the Sash!
- Do not use fume hoods to evaporate hazardous waste. Evaporating hazardous waste is illegal.
- For work involving particularly hazardous substances or chemicals that can form toxic vapors, fumes, or dusts, the hood or equipment within the hood may need to be fitted with condensers, traps, or scrubbers in order to prevent the vapors, fumes, and dusts from being released into the environment.
- Do not exhaust items, such as vacuum pumps, through the face of the fume hood as this will dissupt the airflow into the hood and may cause noncontainment. This will also not allow for the sash to be fully closed.
- As with any work involving chemicals, always practice good housekeeping and clean up all chemical spills immediately. Be sure to wash both the working surface and hood sash frequently and always maintain a clean and dry work surface that is free of clutter.
- In addition to annual fume hood inspection, face velocity testing, and dry ice capture testing, EHS also offers an online training program on the safe use of fume hoods. Additional information can be found in the Safe Fume Hood Use Guide.