Combustibility is a measure of how easily a substance bursts into flame, through fire or combustion.  This is an important property to consider when a substance is used for construction or is being stored.  It is also important in processes that produce combustible substances as a by-product. Special precautions are usually required for substances that are easily combustible.  These measures may include installation of fire sprinklers or storage remote from possible sources of ignition.
Substances with low combustibility may be selected for construction where the fire risk must be reduced, such as apartment buildings, houses, or offices. If combustible resources are used there is greater chance of fire accidents and deaths.  Fire resistant substances are preferred for building materials and furnishings.