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

Class O is not a recognized class of fire under the established classification system for fire types. The widely accepted categories for classifying fires are based on the types of materials that are burning, which are essential for understanding the appropriate firefighting methods and extinguishing agents.

Class A fires involve ordinary combustible materials such as wood, paper, and cloth. Class B fires are fueled by flammable liquids, gases, and greases. Class C fires pertain to energized electrical equipment. Each of these classes has specific recommendations for extinguishers and techniques suited to the characteristics of the materials involved.

In the context of fire safety and extinguisher use, recognizing non-existent classes, such as Class O, is important for staying informed and ensuring the safety measures are suitable for actual fire scenarios. Hence, Class O's absence from the standard classification underscores the need for clear and precise understanding in fire prevention and suppression strategies.