Which of the following is NOT a class of fire extinguisher?

The classification of fire extinguishers is based on the types of fires they are designed to extinguish. Class A extinguishers are used for ordinary combustibles such as wood, paper, and cloth. Class B extinguishers are effective against flammable liquids like gasoline, oil, and paints. Class C extinguishers are for energized electrical equipment, whereas Class D extinguishers are designed for fires involving combustible metals.

Although options A, B, and C represent valid classes of fire extinguishers, Class E is not recognized as an official designation in the NFPA classification system. Typically, fires that would be categorized under a Class E designation are actually addressed by Class C extinguishers, which cover electrical fires. This understanding helps clarify why Class E is not considered a distinct class of fire extinguishers within the established standards.