Which of the following are used to suppress paper or wood fires? Each correct answer represents a complete solution. Choose two.

Question

Options

• ASoda acid
• BKerosene
• CWater
• DCO2

• A
  86% (18)
• B
  10% (2)
• D
  5% (1)

Explanation

Soda acid (A) and water (C) are both effective against Class A fires - the classification for ordinary combustibles like paper and wood. Water works by cooling the burning material below its ignition point, directly halting combustion, while soda acid extinguishers use a chemical reaction between sodium bicarbonate and sulfuric acid to generate CO2 pressure that propels water onto the fire, achieving the same cooling effect.

Kerosene (B) is a flammable liquid and would feed the fire rather than suppress it - never use flammables as fire suppressants. CO2 (D) displaces oxygen and is effective for Class B (flammable liquid) and Class C (electrical) fires, but it is not suited for deep-seated paper or wood fires because it provides no cooling, allowing the material to re-ignite once CO2 disperses.

Memory tip: Think "Class A = water-friendly" - A is for Ash (what paper/wood leaves behind), and water puts out ash-producing fires. Soda acid extinguishers are essentially pressurized water, so both A and C deliver the same core mechanism: cooling.

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