Question The power unit of a placarded vehicle must carry a fire extinguisher with a minimum rating of: Answers 10 B:C. 30 B:C. 40 B:C. Explanation The power unit of a placarded vehicle must be equipped with a fire extinguisher with an Underwriters Laboratories (UL) rating of 10 B:C or more. This questions appears in the following tests: Delaware HazMat Hawaii HazMat Hawaii Tank Idaho HazMat Idaho HazMat Iowa HazMat Louisiana HazMat Maryland HazMat Missouri HazMat Nevada HazMat New Mexico HazMat Ohio HazMat Ohio HazMat Oklahoma HazMat Oklahoma HazMat Utah HazMat Washington HazMat