Firefighter Practice Exam

Sodium bicarbonate is an example of what kind of extinguishing agent?

1. Conductive wetting agent

2. Nonconductive dry chemical

3. Liquified gas

4. Foaming agent

The correct answer is: Nonconductive dry chemical

Sodium bicarbonate is classified as a nonconductive dry chemical extinguishing agent. This is due to its ability to smother flames and interrupt the combustion process by releasing carbon dioxide when it is heated. It is particularly effective on Class B fires, which involve flammable liquids and gases, as well as Class C fires involving electrical equipment. The nonconductive nature of sodium bicarbonate allows it to be safely used on electrical fires, as it does not carry the risk of conducting electricity and causing further hazards. In contrast, conductive wetting agents reduce the surface tension of water, allowing for better penetration in combating fires, but do not offer the same dry chemical properties as sodium bicarbonate. Liquified gases are typically used for different types of fire suppression, and foaming agents are designed specifically to create a barrier between the fuel and the fire, which is not the primary function of sodium bicarbonate. Therefore, identifying sodium bicarbonate as a nonconductive dry chemical is accurate based on its properties and applications in fire suppression.