Philadelphia Fire Department Practice Exam

Which type of fire extinguisher is suitable for electrical fires?

1. Water-based extinguisher

2. Foam extinguisher

3. Dry chemical extinguisher

4. CO2 extinguisher

The correct answer is: Dry chemical extinguisher

The suitable type of fire extinguisher for electrical fires is the dry chemical extinguisher. This type of extinguisher is effective because it releases a fine powder, typically an ABC powder, which can interrupt the chemical reaction that sustains a fire. In the case of electrical fires, using a dry chemical extinguisher is advantageous since it is non-conductive, which ensures that the user remains safe while putting out the fire. In contrast, water-based extinguishers can pose a risk when used on electrical fires, as water is a conductor of electricity and can lead to electrical shock. Foam extinguishers are primarily designed for flammable liquids, and while they may work on some solid combustibles, they are not suitable for electrical fires. CO2 extinguishers can be effective for electrical fires as well, but they have limitations in terms of the fire’s re-ignition potential, as they do not cool the area quite as effectively as a dry chemical extinguisher, which can provide both smothering and cooling effects to prevent re-ignition. Thus, a dry chemical extinguisher is recognized for its versatility and safety, making it the ideal choice for electrical fire suppression.