CDL Hazardous Materials Endorsement (HME)Emergencies and AccidentsMedium
A truck carrying hazardous materials is involved in an accident, resulting in a fire. The material is identified as UN1075, Liquefied Petroleum Gas. What is the PRIMARY concern for firefighters approaching this scene, according to the Emergency Response Guidebook (ERG)?
- AThe rapid spread of fire to surrounding structures.
- BThe environmental contamination from the fire suppression runoff.
- CThe potential for toxic inhalation from the burning gas.
- DThe risk of a Boiling Liquid Expanding Vapor Explosion (BLEVE).
Show answer & explanationAnswer & explanation
Correct answer: D. The risk of a Boiling Liquid Expanding Vapor Explosion (BLEVE).
Liquefied Petroleum Gas (UN1075) is a flammable gas stored under pressure. When involved in a fire, the primary concern is the potential for a BLEVE, where the heated liquid inside the tank expands, causing the tank to rupture violently and release a large fireball. The ERG emphasizes this extreme hazard.
Why the other options are wrong
- A. Fire spread is a concern, but the BLEVE itself is an explosive event with a much wider and more destructive impact.
- B. Environmental contamination is a concern, but secondary to the immediate life-threatening explosion risk.
- C. While toxic inhalation is a concern, BLEVE is the immediate and most catastrophic risk with pressurized flammable gases in a fire.
BLEVE (Boiling Liquid Expanding Vapor Explosion)
A catastrophic explosion that occurs when a liquid stored above its boiling point under pressure (e.g., LPG) is heated, causing the container to rupture violently.
- Common with pressurized flammable gases (e.g., LPG, propane).
- Caused by external fire heating the tank.
- Results in a large fireball and projectile fragments.
Memory trick: Fire on a pressurized tank? Watch out, it might BLEVE!