The most important use of a fume hood is discharging waste present in the air of a laboratory or an area where an experiment using content that emits harmful fumes. In a laboratory setting, tests contain various materials like chemicals, gases, odor, corrosive or flammable items. Fume hoods should be used when working with toxic compounds or compounds with a boiling point below 120C. Fume hoods, or other effective local ventilation, must be provided and used when the materials used will exceed exposure limits in the laboratory.