Under what conditions must a vehicle display placards?

• A. Always required regardless of quantity
• B. Only for radioactive
• C. Only when the material is toxic
• D. When hazmat quantity meets regulatory thresholds and the material requires placarding; placards must be on all four sides

Answer: (D)

Placards are used to warn others and emergency responders about the hazards you’re transporting. They’re required when the hazardous material you’re carrying is one that requires placarding and your total quantity meets the regulatory thresholds. If the material is exempt or the quantity is below the threshold, placards aren’t required. The placards must be displayed on all four sides of the vehicle so the hazard is visible from every approach. So the correct rule is: placards are needed only if the hazmat quantity meets the regulatory thresholds and the material requires placarding, and they must be on all four sides.