Fume hoods serve to control exposure to toxic, offensive or flammable vapors, gases and aerosols. Fume hood is a type of local exhaust ventilation system (engineering control). A typical fume hood is a cabinet with a moveable front sash (window) made out of safety glass. A properly used and properly functioning fume hood exhausts hazardous gases, dusts, mists, and vapors from a confined location and helps protect workers from inhalation exposure.