Basic Firefighter Written Practice Exam

Class B fires primarily involve what type of materials?

1. Gases

2. Solids

3. Flammable liquids

4. Electrical components

The correct answer is: Flammable liquids

Class B fires are specifically associated with flammable liquids and gases. These types of fires involve materials such as gasoline, oil, grease, solvents, and other hydrocarbon-based products. The defining characteristic of Class B fires is the presence of combustible liquids, which can create significant hazards due to their ability to ignite and spread rapidly, especially when they are spilled or aerosolized. In firefighting, the response and extinguishing methods differ significantly based on the class of fire. Since Class B fires are fueled by liquids, water is not an effective extinguishing agent, as it can spread the burning liquid and worsen the situation. Instead, extinguishing agents such as foam, CO2, or dry chemical extinguishers that can smother the flames are used. Thus, the recognition of Class B fires as involving flammable liquids informs how firefighters approach and manage these dangerous situations, making it crucial to understand the materials involved for effective firefighting strategy and safety.