Grease filters shall be

• A. Noncombustible
• B. Combustible
• C. Metalized
• D. Installed at a 90-degree angle

Answer: (A)

Grease filters must be noncombustible. In commercial kitchens, the exhaust system is exposed to high heat and flammable grease, so using noncombustible materials prevents the filter from igniting or feeding a flame. Metal filters, such as stainless steel or aluminum, meet this requirement because they resist heat and can be cleaned regularly. If a filter were combustible, it could ignite and worsen a fire. Metalized filters may still rely on a base material that could be combustible, and orientation (like 90 degrees) doesn’t affect whether the filter material will burn. So, noncombustible is the safe, code-aligned choice.