of the interposed matter among charged parts
(e.g., the air) is created and a spark accompanied by release of energy
(i.e., the heat associated with the spark) can occur. Static charge can,
therefore, be the source of ignition for flammable materials if they are
in the right concentration in air, and can even cause their explosion.2
Flammable materials can explode due to their very rapid combustion,
which causes a sudden increase in their temperature and pressure. Explosive
substances, instead, do not need to be in the right proportion
with the oxygen, and can explode even without it.