A reaction associated with over-pressurization of closed containers that occurs at a rate of 1 second or less is a __________.

• A. BLEVE (Boiling Liquid Expanding Vapor Explosion)
• B. Deflagration
• C. Detonation
• D. Runaway Reaction

Answer: (A)

When a closed container holding a pressurized liquid is heated beyond what its strength can handle, the liquid starts to boil and flash into vapor, causing a rapid rise in internal pressure. If the vessel bursts, the hot liquid and vapor are expelled violently in a very short time—often about a second or less. This explosive rupture and rapid release is the defining feature of a BLEVE (Boiling Liquid Expanding Vapor Explosion). Deflagration and detonation describe combustion waves, with deflagration being slower, subsonic flame spread and detonation being a shock-driven, supersonic event; a runaway reaction describes an uncontrolled chemical reaction inside equipment. None of those capture the specific sudden rupture of a sealed, pressurized vessel due to overheated liquid, which is characteristic of a BLEVE.