Chemical Fume Hoods

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.

Fume Hood Maintenance

EHS Responsibilities:

  • Provide technical support in choosing the proper fume hoods or other engineering controls for working with hazardous substances in research laboratories.
  • Approve the use of special hazardous substances in fume hoods such as:
    • Radioactive material
    • Perchloric acid
  • Certify the fume hoods annually and following maintenance repairs, and maintain records.
  • Write guidance documents about proper use.

Fume Hood Alarms:

If the alarm is sounding, the fume hood has insufficient exhaust air flow and should not be used.

  • When a fume hood alarm sounds, stop work, close the fume hood sash, and call work management at 202-687-3432.
  • Do not ignore/mute the alarm.
  • Laboratory personnel should leave the area if highly toxic or volatile chemicals are being used.


  • If the fume hood is not functioning, contact work management at 202-687-3432.
  • If laboratory personnel are unsure the fume hood is operating correctly, or if there are any questions regarding the fume hood operation/safety, call EHS at 202-687-4712.
  • After maintenance work is performed (new motor, repairs, modifications, relocation, new fume hood installation, etc.), contact EHS to check the air flow and recertify the fume hood.
  • To prevent worker exposure to hazardous chemicals, all chemicals and equipment must be removed from the fume hood prior to maintenance work being done. The hood has to be properly decontaminated following procedures in the Laboratory Equipment Decontamination Form.