Which materials are typically defined as a Class A fire?

Which materials are typically defined as a Class A fire?

• A. Wood, paper, rubber, fabrics, and many plastics
• B. Gasoline, oils, paint, lacquer, and tar
• C. Live electrical equipment
• D. Combustible metals or alloys

Answer: (A)

Fires involving ordinary combustibles—wood, paper, fabrics, rubber, and many plastics—are defined as Class A. These materials burn with a flame and typically form ash, so the key to stopping them is removing heat. Water is effective here because it cools the fuel and surrounding environment, lowering the temperature below the material’s ignition point and halting the flame. The listed materials fit this category because they are common everyday combustibles. The other options point to different fire classes: flammable liquids like gasoline, oils, paints, lacquer, and tar are Class B and are best handled with agents that control vapors and surface burning; live electrical equipment is Class C (electrical) due to the risk of shock and arc; combustible metals or alloys are Class D and require specialized dry powders.

Fires involving ordinary combustibles—wood, paper, fabrics, rubber, and many plastics—are defined as Class A. These materials burn with a flame and typically form ash, so the key to stopping them is removing heat. Water is effective here because it cools the fuel and surrounding environment, lowering the temperature below the material’s ignition point and halting the flame. The listed materials fit this category because they are common everyday combustibles.

The other options point to different fire classes: flammable liquids like gasoline, oils, paints, lacquer, and tar are Class B and are best handled with agents that control vapors and surface burning; live electrical equipment is Class C (electrical) due to the risk of shock and arc; combustible metals or alloys are Class D and require specialized dry powders.