The power unit of a placarded vehicle must have a fire extinguisher with a UL rating of _____ B:C or more.

• A. 5
• B. 10
• C. 15
• D. 20

Answer: (B)

When carrying hazardous materials, you need a fire extinguisher on the power unit that can handle the kinds of fires you might encounter there. A UL rating of 10-B:C means the extinguisher is capable of fighting a hydrocarbon (liquid fuel) fire up to a certain size and is suitable for use on electrical fires. The B rating shows it’s effective against flammable-liquid fires, and the C indicates it won’t conduct electricity or cause shock when used on energized equipment. The power unit area (engine compartment) can have both fuel/oil ignition risks and electrical components, so having at least 10-B:C ensures enough capability to control a small fire quickly and safely. Higher ratings would also meet the requirement, but 10-B:C is the minimum specified.