Chemical fume hoods, when used properly, are one of the most reliable engineering controls in the laboratory. They protect workers by containing vapors, dust, gases and fumes generated within the hood, and removing them from the operators breathing zone via the laboratory exhaust system.
Proper Use of Fume Hoods
- 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.
- Wear at least the minimum personal protective equipment (i.e., lab coat, gloves, and closed-toe shoes). Fume hoods are by no means a replacement for protective wear and good laboratory practices.
- Keep experimental apparatus, and sources of contaminants within the hood at a distance of at least six inches behind the sash opening to avoid disruption of airflow.
- Avoid cross drafts at the face of the hood, as these will disturb the direction of air flow.
- Keep the hood uncluttered; the more cluttered the hood, the more air flow disturbances. Try not to store chemicals in the hood; they should be stored in designated cabinets or on shelves. Storage of materials/ equipment in the hood should be kept to a minimum. No peroxide-forming compounds (e.g., ether) may be stored in the hood.
- 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.
- The use of perchloric acid is not permitted without prior approval. Contact EH&S for assistance.
- Keep your head away from the face of the hood. Keep the sash closed when the hood is not attended.
- The work surface of the hood should be thoroughly cleaned after completion of all experiments and immediately following a spill.
- Remain alert to changes in airflow and be familiar with appropriate emergency procedures in the event of fume hood failure. If you suspect hood failure, stop work immediately and contact the lab/facility supervisor and/or Facilities Management (ext. 7-3432) for repair.