A vehicle contains 500 pounds each of explosives class 1.1 and 1.2. You must use:

• A. EXPLOSIVES 1.1 Placards
• B. EXPLOSIVES 1.2 Placards
• C. UN Placards
• D. No Placards Required

Answer: (A)

Placarding communicates the highest hazard on the vehicle. For explosives,1.1 indicates mass explosion danger, while 1.2 indicates projection danger. When both 1.1 and 1.2 are present, you must display the placard for the more dangerous class, which is Explosives 1.1. That’s why using the Explosives 1.1 placards is correct. The UN placard is not a substitute for the specific class placard, and you wouldn’t omit placards, as the mass-explosion hazard needs to be clearly indicated. Displaying only the 1.2 placard would fail to convey the higher risk.