How does a foam-type fire extinguisher accomplish its function?

How does a foam-type fire extinguisher accomplish its function?

• A. By releasing dry powder
• B. By cooling and smothering
• C. By spraying water
• D. By releasing carbon dioxide

Answer: (B)

A foam-type fire extinguisher is designed to combat certain types of fires, particularly those involving flammable liquids and solids. Its method of operation is primarily through cooling and smothering. When the foam is discharged, it forms a thick blanket over the burning material. This foam cools a fire by absorbing heat and consequently lowering the temperature of the combustible material. At the same time, the foam smothers the flames by creating a barrier that restricts the oxygen supply needed for combustion. This dual action is effective in suppressing fires, minimizing the likelihood of reignition and ensuring that the fire is extinguished thoroughly. The other options do not accurately describe the method used by a foam-type fire extinguisher. While dry powder extinguishers might release powder to smother flames, foam specifically works by both cooling and creating a barrier. Spraying water is effective for different classes of fire, particularly those involving solid combustibles, but it is not the function of a foam extinguisher. Lastly, releasing carbon dioxide is characteristic of CO2 extinguishers, which primarily work by displacing oxygen, not by cooling and forming a barrier like foam extinguishers do.

A foam-type fire extinguisher is designed to combat certain types of fires, particularly those involving flammable liquids and solids. Its method of operation is primarily through cooling and smothering.

When the foam is discharged, it forms a thick blanket over the burning material. This foam cools a fire by absorbing heat and consequently lowering the temperature of the combustible material. At the same time, the foam smothers the flames by creating a barrier that restricts the oxygen supply needed for combustion. This dual action is effective in suppressing fires, minimizing the likelihood of reignition and ensuring that the fire is extinguished thoroughly.

The other options do not accurately describe the method used by a foam-type fire extinguisher. While dry powder extinguishers might release powder to smother flames, foam specifically works by both cooling and creating a barrier. Spraying water is effective for different classes of fire, particularly those involving solid combustibles, but it is not the function of a foam extinguisher. Lastly, releasing carbon dioxide is characteristic of CO2 extinguishers, which primarily work by displacing oxygen, not by cooling and forming a barrier like foam extinguishers do.