What dangerous event occurs when a pressurized liquid rapidly vaporizes and expands, potentially causing an explosion?

• A. Flashover
• B. Runaway cracking
• C. Boiling Liquid Expanding Vapor Explosion (BLEVE)
• D. Thermal Runaway

Answer: (C)

The phenomenon described in the question is known as a Boiling Liquid Expanding Vapor Explosion (BLEVE). This dangerous event occurs when a pressurized liquid, typically contained in a vessel, is heated to the point where it vaporizes rapidly. The increase in temperature results in a corresponding increase in pressure within the vessel. If the pressure exceeds the vessel's design limits, the vessel may fail catastrophically. When the liquid rapidly vaporizes, it expands significantly, and this expansion can lead to an explosion, causing potential damage to the surrounding area and significant safety hazards for people nearby.

BLEVEs are particularly concerning because they can happen without warning and can result in the release of flammable gases and the ignition of these gases, leading to fires and additional explosions. Understanding this process is critical for emergency responders and hazardous materials professionals, as it helps them recognize the signs of an impending BLEVE and take appropriate safety measures.