Fume hoods are a primary method of exposure control in the laboratory. A fume hood is a ventilated enclosure that usually vents separately from the building’s heating, ventilation and air conditioning (HVAC) system and not recirculated into the building. Fume hoods should be used when working with toxic compounds or compounds with a boiling point below 120°C. Fume hoods, or other effective local ventilation, must be provided and used when the materials used will exceed exposure limits in the laboratory.
Standards for determining permissible exposure limits include: