When selecting a fire extinguisher, what factors determine the appropriate class?

• A. The type of fuel and the associated fire class (A, B, C, D, K)
• B. The room size and occupant density
• C. The color of extinguisher and its location
• D. The brand and price of extinguisher

Answer: (A)

When choosing a fire extinguisher, you match the extinguisher to the fuel that could burn. Extinguishers are labeled with fire classes that describe the kind of fire they’re designed to suppress (A for ordinary combustibles, B for flammable liquids, C for electrical fires, D for metals, K for cooking oils). The right extinguisher either covers the specific class you expect to encounter or is a multi-class type (like ABC) that covers several hazards. Factors like room size, occupant density, or brand don’t determine the class—they influence other aspects like capacity or placement, but not which class is appropriate. Using the correct class is also a safety issue: using the wrong type can be ineffective or dangerous, such as using a water extinguisher on an electrical fire. So the key is identifying the fuel source and selecting the extinguisher rated for that fire class (or for multiple applicable classes).