What rating of fire extinguisher must a power unit used to transport hazardous materials have, according to the Federal Motor Carrier Safety Regulations?

A power unit used for transporting hazardous materials is required to have a fire extinguisher rated at a minimum of 10 BC according to the Federal Motor Carrier Safety Regulations. This rating indicates the effectiveness of the extinguisher for fighting fires involving flammable liquids and electrical equipment, which are critical considerations when dealing with hazardous materials.

The "B" rating refers specifically to flammable liquids, while the "C" rating refers to live electrical equipment. Therefore, a 10 BC rating signifies that the fire extinguisher is effective for certain sizes of fires involving both types of hazards. This requirement ensures that drivers have the proper equipment to respond to potential fire hazards that may arise during transport, thereby enhancing the overall safety of operations involving hazardous materials.