What method used to extinguish fires involves cooling and excluding oxygen?

The method used to extinguish fires that involves cooling and excluding oxygen is smothering. This technique is effective because it cuts off the fire's supply of oxygen, which is necessary for combustion.

When an oxygen source is eliminated or significantly reduced, the fire cannot sustain itself and is effectively extinguished. Smothering is commonly achieved by covering the fire with a material that prevents air from reaching the flames, such as dirt, foam, or a fire blanket. Additionally, while the smothering material may not significantly cool the fire itself, the primary mechanism at work is the restriction of oxygen, which leads to the cooling of the flames as they extinguish.

The other methods, while relevant to fire suppression, do not combine both cooling and oxygen exclusion in the same way. For example, blanketing involves covering the fire with foam to prevent combustion but may not necessarily remove oxygen. Similarly, dilution involves mixing the burning material with water or another substance to lower its concentration, which does not focus primarily on shutting off the oxygen supply. Wetting, on the other hand, primarily employs water to cool the fire and the burning material, but does not effectively exclude oxygen.

Therefore, the process of smothering is uniquely characterized by its dual function