What type of fire extinguisher uses CO2 and leaves no residue?

The correct answer is that a Class C fire extinguisher uses carbon dioxide (CO2) as its extinguishing agent and leaves no residue. Class C fire extinguishers are specifically designed for electrical fires, where non-conductive agents are necessary to safely extinguish the flames without the risk of conducting electricity. CO2 is particularly effective because it displaces the oxygen around the fire, suffocating it while also being safe for use on equipment and surfaces that could be damaged by other types of extinguishing agents, such as foam or water.

In addition to leaving no residue, which is crucial for protecting sensitive electrical components, CO2 extinguishers are lightweight and easy to operate, making them suitable for quick action in emergency situations. The focus of Class C extinguishers on electrical hazards emphasizes their unique purpose and application in areas with electrical equipment, clearly distinguishing them from the other classes of extinguishers.

Classes A, B, and D extinguishers are used for different types of fires. Class A is for ordinary combustibles, Class B is for flammable liquids, and Class D is specialized for combustible metals, each of which utilizes different agents that may leave residues or may not be suitable for electrical application.