A listed or approved grease duct system that is four stories or less shall be provided for which type of exhaust?

• A. Ventilation hood systems
• B. Recirculated air systems
• C. Solid cooking exhaust systems
• D. General ventilation ducts

Answer: (C)

Grease-laden exhaust from solid cooking equipment requires a listed or approved grease duct system. Solid-fuel cooking generates more grease and higher heat, which raises the fire risk inside ducts. Using a grease-drated duct designed and listed for carrying grease-laden air helps contain any fire, provides proper fire stopping, and allows safe cleaning and inspection. The four-story-or-less limit indicates this is the scenario where such specialized ductwork is mandated. Other exhaust types—such as general ventilation or recirculated air systems that don’t vent heavy grease outdoors—do not present the same grease-fire hazard and therefore don’t require the same grease-duct construction.