What is Fire?

Fire is a powerful force. It’s hypnotic, awe-inducing, and at the same time primal and dangerous. It’s also vitally important to many of the world’s ecosystems, helping to maintain biodiversity and stabilising slopes. But what is it exactly? Fire is the visible result of a special type of chemical reaction called combustion. It happens when some sort of fuel burns and releases heat energy, destroying some of the starting material and producing other new materials such as carbon dioxide and water. For fire to occur, it needs three things: oxygen from the air, fuel, and some form of energy to initiate the chemical reaction. This is called the fire triangle. If any one of these is missing, the reaction stops.

To produce flames, the fuel must be heated to a high enough temperature for it to evaporate. This releases gases into the air that mix with oxygen from the surrounding air to form new molecules, which emit heat and produce flames. The gasses may then condense back into a liquid or solid form. If a fire is still burning, it continues to release more gases that mix with more oxygen and create more flames. This process is known as combustion and produces heat energy, and it will continue as long as the fuel and oxygen remain in supply.

The flames from a fire radiate heat in all directions, heating nearby objects and the air around them. This heat energy can be transferred in several ways: radiation, convection, and conduction. Radiation is when the heat travels through a substance without touching it; convection is when the hot gases move upwards, causing objects on lower levels to be warmer than those on higher levels. Conduction is when the heat transfers through a solid or liquid, transferring its energy to the particles of that matter.

In a burning building, the gases from the fire can accumulate in the space between the walls. This can increase the pressure inside a room and make it seem like the building is “breathing” or throbbing. It can also cause suffocation.

Fires can be extinguished by cooling the fuel to its ignition temperature, using a fire retardant such as Halon (now banned in some countries), or by introducing a catalyst to speed up the chemical reaction. The best way to prevent fires is by being vigilant, making sure that electrical equipment is not overloaded and not blocking airflow; and by regularly checking smoke alarms and having a working fire escape plan.

If you see smoke or flames, get out of the building and call 911 immediately! Keeping up with the latest information and training is essential. The best way to learn about fire is through hands-on training with a qualified professional trainer. To find one near you, visit the National Association of Fire Investigators website.