Class A fires involve which materials?

Class A fires involve which materials?

• A. Ordinary combustibles
• B. Flammable liquids
• C. Electrical equipment
• D. Metals

Answer: (A)

Fires are categorized by the type of fuel involved, because different fuels require different ways to stop the blaze. Class A refers to ordinary combustibles—materials that burn cleanly and leave ash. Common examples are wood, paper, cloth, rubber, and many plastics. Because these fuels can be cooled, water-based extinguishing methods are especially effective, as they absorb heat and bring the temperature of the fuel below its ignition point, halting combustion. Flammable liquids burn as vapors and are best tackled with methods that control vapors and cut off the fuel source, not by cooling with water. Electrical fires involve energized equipment and require first de-energizing the circuit and using non-conductive extinguishing media to avoid shock. Metals fires demand special extinguishing agents and techniques, since many standard extinguishing methods can be ineffective or dangerous. So the materials described are ordinary combustibles.

Fires are categorized by the type of fuel involved, because different fuels require different ways to stop the blaze. Class A refers to ordinary combustibles—materials that burn cleanly and leave ash. Common examples are wood, paper, cloth, rubber, and many plastics. Because these fuels can be cooled, water-based extinguishing methods are especially effective, as they absorb heat and bring the temperature of the fuel below its ignition point, halting combustion.

Flammable liquids burn as vapors and are best tackled with methods that control vapors and cut off the fuel source, not by cooling with water. Electrical fires involve energized equipment and require first de-energizing the circuit and using non-conductive extinguishing media to avoid shock. Metals fires demand special extinguishing agents and techniques, since many standard extinguishing methods can be ineffective or dangerous.

So the materials described are ordinary combustibles.