Before we learn how to extinguish a fire, let us introduce the three elements of combustion 1. Air 2. Heat 3. Fuel All of the elements above are indispensable for a fire to burn successfully. Therefore, once any of the elements are removed, the fire will be extinguished.
The three most common ways to extinguish a fire are:
1. Suffocation The concentration of oxygen in the air is generally 21%, and when the concentration drops below 15%, the flame cannot maintain normal combustion. Therefore, as long as the oxygen in the air is excluded, isolated or diluted, the fire will be extinguished. For example, if a pot is on fire during cooking, you only need to cover the pot to isolate the fire from the air, and when the oxygen in the pot is consumed, the fire will be extinguished. Alternatively, use carbon dioxide fire extinguishers to quickly reduce the oxygen concentration in the air to achieve the same effect.
2. Cooling The flame must have a sufficient temperature to burn continuously, so when the temperature is reduced below the ignition point, combustion will stop. For instance, firefighters use a powerful water hose to cool the fire down when extinguishing fires. Water absorbs the heat energy to cool the burning medium quickly, thus the fire extinguishes.
3. Isolation The flame cannot burn with the lack of fuels. As long as the combustible material is separated ↔️ from oxygen and the flame, the combustion will be interrupted. That is why fires can be controlled or mitigated by cutting down trees to create barriers in the event of a forest fire. Since trees are their primary combustible material, combustion is terminated when the fire loses fuel to burn when it spreads to the barrier zone.