Grease duct

A grease duct is a duct that vents grease-laden flammable vapors from commercial cooking equipment such as stoves, deep fryers, and woks to the outside of a building or mobile food preparation trailer.

Grease ducts are part of the building's passive fire protection system.

The cleaning schedule is typically dictated by fire code or related safety regulations.

Purpose-designed fire suppression systems inside the hoods must also be routinely maintained.

[1][better source needed] Hazards associated with improperly maintained hoods include, but are not limited to, poor ventilation, excess heat and smoke, and the potential risk of fires.