Firefighter Practice Exam

Which type of fire extinguisher should you NOT use on electrical fires?

1. Class A

2. Class B

3. Water-based

4. Class D

The correct answer is: Water-based

Using a water-based fire extinguisher on electrical fires is dangerous and can lead to severe consequences. Water conducts electricity, which poses a significant risk of electrocution to the operator and can spread the fire by creating conductive paths. Electrical fires often require specific extinguishing agents that do not conduct electricity. For instance, Class C extinguishers are designed specifically for fires involving energized electrical equipment, as they use non-conductive agents to safely extinguish the flames without the risk of electrical shock. Notably, Class A extinguishers are suitable for ordinary combustibles, such as wood and paper, and Class B extinguishers are meant for flammable liquids and gases. Class D extinguishers are used for combustible metals, which typically do not apply in electrical fire scenarios. Hence, during an electrical fire incident, it is essential to avoid water-based extinguishers to ensure safety and effectively manage the situation.