How are fire extinguishers matched to fire classes (A, B, C, D, K)?

• A. Extinguishers are selected based on the fuel and electrical class of the fire they are designed to control (A, B, C, D, K).
• B. They are selected based on the color of the extinguisher.
• C. They are selected by the building's age.
• D. They are selected randomly.

Answer: (A)

Extinguishers are matched to fire classes based on what’s burning and whether electricity is involved. Each class describes a specific hazard: Class A for ordinary combustibles like wood and paper; Class B for flammable liquids; Class C for energized electrical equipment; Class D for certain reactive metals; Class K for cooking oils and fats. The extinguishing agent must interrupt the flame without creating a new hazard or conducting electricity. That’s why you choose a medium that is appropriate for the class: water or water-based agents work well on Class A fires, but are unsafe for Class B, C, D, or K. For liquids, foam or dry chemical extinguishers are common; for electrical fires, non-conductive agents like CO2 or dry chemical are preferred; for metal fires, a specialized dry powder is used; and for kitchen oil fires, a wet chemical extinguisher is designed for that specific hazard. Many extinguishers are rated for multiple classes, so they can handle several kinds of fires they might encounter.

Color alone isn’t a reliable indicator of what class an extinguisher can combat, and the age of a building or choosing a extinguisher at random doesn’t relate to fire safety.