Which of the following best describes foam extinguishers?

Foam extinguishers are specifically designed to tackle flammable liquid fires, which typically fall under Class B fires. They work by forming a blanket of foam over the burning liquid, creating a barrier that prevents oxygen from reaching the fuel and effectively smothering the flames. This capability makes foam extinguishers particularly effective for fires involving substances like gasoline, paint, and other common flammable liquids.

The physical properties of foam, including its ability to minimize the release of flammable vapors and provide cooling as it expands, contribute to its effectiveness in suppressing flammable liquid fires. Understanding this function is crucial for safe fire control strategies, as appropriate extinguisher selection is a key component in successfully managing different types of fires.