The H2O extinguisher is suitable for which type of fires?

• A. Class B fires
• B. Class C fires
• C. Class A and PED fires
• D. Class D fires

Answer: (C)

Water extinguishers work by absorbing heat, cooling the burning material until it can no longer sustain combustion. That cooling action makes them effective on fires involving ordinary combustibles like paper, wood, and fabric. In a cabin setting, a fire contained within a portable electronic device (PED) can also be tackled with water because cooling the device can stop the ignition and prevent the flame from spreading to nearby materials, provided the device can be isolated from power. This combination—cooling for Class A fires and effective control of a PED fire when power is or can be disconnected—explains why water extinguishers are considered suitable for these scenarios. They’re not used for fires involving flammable liquids, energized electrical equipment, or metal fires, which require different agents.