Washington State University
Environmental Health & Safety Maintenance of Ventilation Systems

Maintenance of Ventilation Systems

  • Laboratory ventilation systems including fume hoods are the primary methods of protection from hazardous chemical vapors, fumes and potential contamination. These systems must be maintained regularly to ensure proper performance. To request repairs or changes to the ventilations system, submit a MyFacilities work request or contact WSU Facilities Operations at 335-9000.
  • For further information see Section II.J.3, Fact Sheets — Chemical Fume Hoods
  • Facilities Operations performs periodic maintenance and testing of fume hood and other protective equipment to ensure that they are functioning properly. The maintenance and testing includes:
    • Annual testing of fume hood face velocity to determine that an appropriate volume and velocity of air is entering the fume hood.
    • The fume hood testing technician affixes two stickers to the fume hood; a permanent sticker which indicates proper face velocity and also states general rules for fume hood usage, and a temporary sticker which indicates the last measured face velocity of the fume hood and the date of measurement. These stickers are pictured below. To print the stickers, click here


    • If the face velocity tested on the fume hood is significantly lower (or higher) than the allowable limit indicated, the Facilities Operations technician will tag out the fume hood until repairs are made. The fume hood will not be operated until the tag has been removed by Facilities Operations.
    • In addition, complaints or concerns submitted by fume hood operators will be investigated by Facilities Operations.
  • Laboratory ventilation equipment scheduled for maintenance or repair work must be cleaned and/or decontaminated by laboratory personnel under the supervision of the PI or laboratory supervisor. Maintenance workers have the right to refuse to do work if the area or equipment is not clear of hazards. (See Section III.E.3, Maintenance/Construction Activities in Laboratories ).
  • All ventilation systems require routine maintenance for blocked or plugged air intakes and exhausts, loose belts, bearings in need of lubrication, motors in need of attention, corroded duct work, and/or minor component failure.
  • Filters should be replaced periodically in certain types of ventilation systems, such as electrostatic precipitators and cyclones for dust collection.
  • Monitoring devices are installed in ventilation systems to keep the user aware of malfunctions.