What technique is often used to suppress flammable liquid fires?

Smothering is an effective technique used to suppress flammable liquid fires because it involves depriving the fire of the oxygen it needs to maintain combustion. Flammable liquids burn in the presence of oxygen, and by covering the liquid with a suitable material, such as foam, or using dry chemicals, you can create a barrier that prevents oxygen from reaching the burning liquid. This interrupts the combustion process and helps to control or extinguish the fire.

In the context of flammable liquids, techniques like cooling, starvation, and breaking may not be as effective. Cooling can reduce the temperature of the liquid and surrounding materials but might not necessarily eliminate the flame if there is still adequate oxygen. Starvation, which involves cutting off the fuel supply, is less applicable in a situation where the liquid itself is the fuel source. Breaking generally refers to the disruption of a fire, which does not effectively address the need to limit oxygen availability. Thus, smothering stands out as the most appropriate and commonly utilized technique for flammable liquid fires.