For a fire to occur there must be a source of ignition, fuel and oxygen. If all three are present and in close proximity, then the fire risk could increase. In an average premise fire hazards fall into the first two categories, while the oxygen is present in air in the surrounding space.
For supper high-rise buildings, Can divide the dangers of fire has 3 types.
Type I Potential sources of fuel
Type II Potential sources of ignition
type III The failure of equipment and systems