Tennessee Wastewater Operator Practice Exam

Which of the following should not be used to extinguish electrical fires?

1. Water extinguishers

2. Foam extinguishers

3. Class C extinguishers

4. Dry powder extinguishers

The correct answer is: Water extinguishers

Using water extinguishers on electrical fires is highly unsafe because water is a conductor of electricity. If water is applied to an electrical fire, it can lead to the risk of electrocution for the person extinguishing the fire and can also exacerbate the fire by conducting electricity to nearby conductive materials or surfaces. On the other hand, foam extinguishers, Class C extinguishers, and dry powder extinguishers are specifically designed to tackle electrical fires without the risks associated with water. Foam extinguishers can be effective on some flammable liquid fires but are not suited for electrical fires. Class C extinguishers are designated for electrical fires, using non-conductive agents to extinguish the flames safely. Dry powder extinguishers are versatile and can also be used effectively on electrical fires because they do not conduct electricity and can smother the flames. It's crucial to choose the correct type of extinguisher to ensure safety and effectiveness when dealing with different types of fires.