UNIVERSITY OF WISCONSIN River Falls

Lab Hood Safety

Chemical Set10 Points for Safe Lab Hood Use 

  1. Always operate the hood with the vertical sash as low as practical.
  2. Always work at least 6 inches into the hood.
  3. Limit chemical storage in lab hoods.  Hoods are not intended for storage; after use chemicals should be moved from hoods to vented cabinets for storage. Hoods are not intended for storage!
  4. Hoods should not be regarded as a means for disposing of chemicals.  Apparatus used in hoods should be fitted with condensers, traps, or scrubbers to contain and collect waste solvents, toxic vapors or dust.
  5. When using large apparatus inside the hood, place the apparatus on blocks when safe and practical to allow air flow beneath it.  If the hood is equipped with horizontal sashes, keep them closed as much as practical.  Keeping the hood opening small will increase overall performance.
  6. Sliding sashes should not be removed from horizontal sliding-sash hoods.  The hood should be kept closed, except when adjustments or apparatus within the hood are being made.  Use sliding sash for partial protection during hazardous work.
  7. Do not lean into the hood, make quick motions into or out of the hood or walk quickly by the hood opening since this causes airflow disturbances.
  8. Use the right hood for the job.
    • General Purpose
    • Perchloric Acid
    • Radioisotopes Biological

      Label hoods for special use when appropriate.

  9. Regular inspection of the lab hood should be done by Physical Plant or environmental Health and Safety staff to ensure that it is operating properly.  hoods should be evaluated before use to ensure adequate face velocities and the absence of excessive turbulence.
  10. Hoods not in use should be turned off to conserve energy, unless posted otherwise.  If any doubt exists, however, or if toxic substances are temporarily in the hood, the exhaust system should be in operation.