Class 5 Boiler Practice Exam

What type of fire is fueled by electrical sources?

1. Class A fire

2. Class B fire

3. Class C fire

4. Class D fire

The correct answer is: Class C fire

Class C fires are specifically fueled by electrical sources, including energized electrical equipment such as wiring, circuit breakers, and appliances. The unique aspect of Class C fires is that the fire involves flammable materials that are electrical in nature and not simply combustible solids, liquids, or gases. When dealing with a Class C fire, it is crucial to understand that using water or foam to extinguish it is not safe, as these can conduct electricity and create a risk for electrical shock. Instead, specialized extinguishing agents like carbon dioxide or dry chemical extinguishers that are effective for electrical fires should be used. This distinction emphasizes the importance of recognizing the source of the fire in order to apply the correct safety measures and methods for extinguishment. In contrast, Class A involves ordinary combustibles, Class B pertains to flammable liquids and gases, and Class D relates to combustible metals. Understanding these classifications helps ensure safe and effective fire management practices.