To know which placards to use, you need to know: Question To know which placards to use, you need to know: Answers The hazard classes of the materials. The types of containers holding the materials. The destination. The shipper. Explanation To determine which hazardous materials placards to use, you must know the hazard class of the materials; the amount of hazardous materials being shipped; and the total weight of all classes of hazardous materials in the vehicle. This questions appears in the following tests: District Of Columbia HazMat Georgia HazMat Indiana Tank North Dakota HazMat Utah HazMat West Virginia HazMat Wisconsin HazMat Wisconsin Tank Wyoming HazMat