A bit of info that many emergency responders do not know! A Boiling Liquid Expanding Vapor Explosion (BLEVE) can occur with non-flammable materials such as cryogenics like liquid Oxygen, Nitorgen, etc. All we need to have in place for a BLEVE to occur is a material with a high vapor pressure (thus a low BP), a pressurized container, and an external fire impinging on the container walls. Granted, a BLEVE involving a flammable material such as LPG will generate more energy when the container fails, but a BLEVE is the actual failure of the container due to the boiling liquid inside generating more pressure than the relief valve can handle, all the while the liquid level is dropping and thus leaving the metal walls to absorb all the heat, thus weakening the wall to a point of failure. Once the wall fails, we have the hot liquid already well above it’s boiling point inside the vessel, which is under a high pressure already. Once the breach allows the gas on top of the liquid to escape we have an almost instantaneous transformation of the liquid to a gas (which some have expansion ratios 1,000’s to 1). This rapid transformation will launch the container and send out a pressure shock wave a long ways (up to 1500 feet). If the gas happens to be flammable, then we will have ignition of the gas/vapor, thus producing even more energy. If you watch some of the videos on Youtube of BLEVE’s and stop the video at the point of container failure you will see a rapidly expanding white cloud. This is the “boiling liquid expanding” to a vapor state. Basically…we can not think of a fire ball type explosion in a BLEVE as the explosion can be just the catastrophic failure of the container that produces the “explosion” of the BLEVE. I have reviewed the Wikipedia page on BLEVE’s and feel it is one of the best and CORRECT explanation of a BLEVE.