The Fire Triangle in Fire-fighting and Fire Prevention

The fire triangle represents the three elements that a fire needs to ignite: heat, fuel, and oxygen.
Removing any one of these elements will result in the fire being extinguished.
Heat provides the initial energy required to start a fire. It can be provided through friction, a spark, hot surfaces, or even sunlight.
Fuel is a combustible material that can be solid, liquid, or gas. Solid fuels could include wood, cloth, paper and certain metals, whereas liquid fuels could include petrol, diesel and alcohols, and gaseous fuels could include methane, butane, and hydrogen.
Oxygen, usually from the air, reacts with the fuel in an exothermic reaction, releasing heat and light.
When understanding fire-fighting techniques and fire prevention, the main strategy involves removing one or more of the elements of the fire triangle. For example, a water-based fire-extinguisher cools the fire (removing heat) and displaces oxygen, while a CO2 fire extinguisher displaces the oxygen.
In fire prevention, materials are chosen that are less likely to ignite or burn quickly (removing fuel), while fire doors and other barriers are used to limit the supply of oxygen.
Different types of fire require different firefighting methods due to the different kind of fuels they can involve. For instance, a grease fire in a kitchen cannot be put out with water; instead, a fire blanket or wet chemical extinguisher is used to smother the flame and cut off the oxygen supply.
Understanding the fire triangle’s components can also help in predicting and assessing the dangers of certain types of fires, such as those involving chemical reactions or flammable materials. For example, if a fire started in a room full of stored propane tanks, knowing that propane is a flammable gas that could fuel the fire helps in assessing the potential risk of the situation.