Colorado CDL Practice Test

What type of materials are commonly involved in class-O fires?

1. Wood and paper

2. Gas and oil

3. Electrical equipment fires

4. Combustible metals

The correct answer is: Wood and paper

In the context of fire classifications, class-O fires typically refer to those involving ordinary combustibles, specifically materials such as wood and paper. These materials ignite easily and burn rapidly, which is characteristic of class-O fires. When responding to this type of fire, it is essential to use the appropriate fire extinguishing methods, such as water or foam, which are effective against ordinary combustibles. Understanding the nature of class-O fires helps ensure the correct approach is taken, both for safety and effectiveness in extinguishing the fire. The other options represent different classes of fires: combustible metals, gas, and oil, and electrical equipment fires each belong to their own specific fire classifications (like class D for combustible metals, class B for flammable liquids, and class C for electrical fires). Recognizing the differences helps in selecting the right extinguishing agent and handling procedures for each type of fire.