Polypropylene Chemistry Chemical Fume Hood with 220V 50HZ for Laboratory and Chemical Research Facilities

A fume hood is typically a large piece of equipment enclosing five sides of a work area, the bottom of which is most commonly located at a standing work height.

Two main types exist, ducted and recirculating (ductless). The principle is the same for both types: air is drawn in from the front (open) side of the cabinet, and either expelled outside the building or made safe through filtration and fed back into the room. This is used to:

• protect the user from inhaling toxic gases (fume hoods, biosafety cabinets, glove boxes)
• protect the product or experiment (biosafety cabinets, glove boxes)
• protect the environment (recirculating fume hoods, certain biosafety cabinets, and any other type when fitted with appropriate filters in the exhaust airstream)

Secondary functions of these devices may include explosion protection, spill containment, and other functions necessary to the work being done within the device.

Fume hoods are generally set back against the walls and are often fitted with infills above, to cover up the exhaust ductwork. Because of their recessed shape they are generally poorly illuminated by general room lighting, so many have internal lights with vapor-proof covers. The front is a sash window, usually in glass, able to move up and down on a counterbalance mechanism. On educational versions, the sides and sometimes the back of the unit are also glass, so that several pupils can look into a fume hood at once. Low air flow alarm control panels are common.