For combustion to take place, three things must be present:

1. Fuel - the substance that burns, e.g. wood, oil.

2. Oxygen - when a fuel is burned it is reacting with the oxygen in the air.

3. Heat - this ignites the fuel and keeps the fire burning.

This can be represented in a diagram known as the fire triangle:

The three essential ingredients for a fire are shown in the fire triangle. If any one of these ingredients is removed the fire will go out.

Fire fighters will try to remove one side of the triangle to extinguish a fire. There are several ways to extinguish a fire.  Here are some:

Sand: When sand is added to a fire it removes the oxygen.

Fire blankets: Fire blankets can be wrapped around burning objects or people. The blanket stops oxygen getting to the flame.

Carbon dioxide (CO₂): Carbon dioxide fire extinguishers are sprayed onto the fire to remove the oxygen.

Water: Water can be added to fires to remove the heat. Water must never be used on an electrical fire or any burning oil. Adding water to burning oil will cause the fire to become fiercer. Shown below is a picture of what happens when water is added to burning oil in a chip pan (not good!):

If you ever experience a chip pan fire in your home place a damp towel over the pan, call 999 and leave the house.

Let's have a go at some questions now.