When using foam, which method is appropriate for applying it to a fire?

Using foam effectively on a fire involves specific techniques that maximize its potential for suppressing flames. The method identified as "Roll on and rain down" is the most appropriate for applying foam to a fire because it promotes effective coverage of the burning surface, ensuring that the foam smothers the fire and prevents re-ignition.

This technique allows the foam to flow onto the fire, creating a blanket that suffocates the flames by cutting off the oxygen supply. The "roll on" part ensures that the foam is applied directly onto the burning material, which is essential for effective fire suppression. The "rain down" aspect further helps to disperse the foam over a wider area, providing additional coverage and enhancing the foam's ability to suppress hot spots or flare-ups that may occur.

In contrast, other methods like "Spray and leave" do not provide sustained coverage and can lead to re-ignition since the foam is not adequately applied to the fuel. "Mix and dump" lacks control and precision, thus increasing the risk of ineffective application. The "Direct and mist" method may lead to inadequate foam suppression, as it may not cover the fire effectively enough to extinguish it.

Therefore, "Roll on and rain down" is the proven method