Liquids involved:
(1) liquified petroleum gas (LPG)
(2) liquid propane
Mechanism:
(1) Flammable liquid usually has a low vapor pressure, and it boils at a relatively low temperature.
(2) The heat from the fire causes the liquid to boil with generation of gas, resulting in a rapid rise in pressure within the container.
(3) When the pressure exceeds the capacity of the tank material, the container ruptures, releasing the liquid and gas into the fire.
(4) The released liquid and gas ignite, causing an explosion.
Factors determining outcomes:
(1) size of the tank
(2) flammability of the liquid and gas
(3) tank material
(4) presence of a functioning pressure release valve
(5) size of the inciting fire
(6) proximity of people at the time of the explosion
(7) ability to quench the outside fire and cool the tank, which is often dependent on having an adequate water supply
(8) compliance with safety regulations for placement of storage tanks
Hazards:
(1) The explosive blast.
(2) Shrapnel from the container.
(3) Burn injury from fireballs or fires.
(4) Occurrence in a confined space, such as a tunnel or ship.
(5) Occurrence as part of a transportation accident (train derailment, traffic accident, etc.)
Software programs are available that can model BLEVE explosions using the known parameters.
