What is fire?

Fire, pretty essential really and something we often take for granted, but what exactly is it? Well to create fire you need three things – some fuel, a heat source and oxygen. If we remove any one of these, then the fire will go out. When we apply sufficient heat to the fuel for it to reach its ignition point, the material will combust in the presence of oxygen.

Combustion is actually the process by which the fuel decomposes, its molecules breaking down, releasing and recombining with the oxygen to produce water, carbon dioxide, carbon monoxide and all sorts of other things.

The flames which we see are composed of incandescent soot, this is not fire, as ethanol for example, can produce fire without visible flames. Incandescence increases with temperature and so we can estimate the heat of the flames moving from red, through orange, to the hottest of all – white heat.