- Portable fire extinguishers are classified based on the type of fuel that is burning and appropriate extinguishing agents are chosen accordingly. Common classifications include Class A for ordinary combustibles, Class B for flammable liquids, Class C for energized electrical fires, Class D for combustible metals, and Class K for cooking oils.
- Fire extinguishers are also rated based on their capabilities. Ratings identify the types of fires they can be used on as well as their relative sizes. Instruction and practice is needed to properly select, inspect, maintain, and operate portable fire extinguishers for controlling small fires.