Which of the following statements about foam is true?

Foam can smother a fire by forming a blanket over the burning material, which effectively cuts off the oxygen supply necessary for combustion. This suffocation effect is critical in extinguishing a fire, especially in situations involving flammable liquids. The foam works by creating a barrier that prevents the flames from coming into contact with the fuel, thereby inhibiting the fire's ability to sustain itself. In addition to this smothering capability, foam can also provide cooling effects, but its primary advantage lies in its ability to suffocate the fire.

While it's important to recognize that foam does have various mechanisms of action, such as cooling and sealing in vapors, the statement about smothering reflects one of the fundamental principles of foam firefighting tactics. The other statements do not accurately encapsulate the capabilities of foam in fire suppression strategies. For instance, foam does contribute to cooling, but it doesn't work exclusively this way; rather, it primarily smothers and provides a cooling effect simultaneously.