2.1 Chemical Fume Hoods
Fume hoods and other local exhaust capture devices are designed to contain the release of hazardous vapors, fumes, gases, and dusts. Use of hazardous chemicals on the open benchtop is strongly discouraged. A fume hood must be used when working with materials that present an inhalation hazard, when conducting new or unknown chemical reactions, or when operations may generate heat, flames, or pressurized reactions.
Safe and Effective Fume Hood Use
To achieve optimum containment, personal protection, and energy efficiency:
- Verify proper hood operation before use. Check the airflow monitor or Magnehelic gauge if one is installed. If no monitor is present, verify airflow using the paper tell-tale (crepe paper strip) at the sash opening.
Do not use a hood that appears to be malfunctioning. - If the hood is not functioning properly, notify the building coordinator or Facilities and Campus Services (FCS) immediately. Post a “Do Not Use” sign on the hood until repairs are completed:
Do Not Use Sign (docx) - Work at least 6 inches inside the hood. Position equipment as far back as practical to maintain stable airflow and maximize containment.
- Do not block the baffles or place equipment on the lower airfoil. Obstructions reduce airflow and compromise containment.
- Keep the sash at the recommended operating height. Lower sashes improve containment and reduce energy use.
- Close the sash completely whenever the hood is not in use.
- Do not use fume hoods to evaporate hazardous waste. Evaporating hazardous waste is illegal under state and federal environmental regulations.
- For particularly hazardous substances (select carcinogens, reproductive toxins, volatile toxics, sensitizers, or reactive compounds), use additional engineering controls such as condensers, traps, or scrubbers to prevent release to the environment.
- Do not exhaust equipment such as vacuum pumps through the face of the hood. This disrupts airflow and prevents proper sash closure.
- Maintain good housekeeping. Keep the work area clean and free of clutter, wipe down surfaces regularly, and promptly clean chemical spills.
Testing, Inspection, and Training
Annual fume hood performance testing is performed by Facilities and Campus Services (FCS) Controls, including face velocity measurement and airflow pattern checks.
EHS evaluates hood use and ventilation conditions during routine laboratory safety assessments and provides guidance on safe hood operation and laboratory ventilation practices.
EHS offers an online Fume Hood Safety training program and maintains additional guidance in the Safe Fume Hood Use Guide.