At what weight must hazardous materials be placarded according to regulations?

Hazardous materials must be placarded when they are transported in amounts that exceed 1,000 pounds. This regulation is in place to ensure safety during the transportation of hazardous substances, as larger quantities pose a greater risk in the event of an accident or spill. The requirement for placarding at this weight allows for quick identification of the nature of the materials being transported, which is crucial for emergency response teams to manage potential risks effectively. This system helps to inform first responders about the presence of hazardous materials and the appropriate precautions that need to be taken. The weight threshold of 1,001 pounds specifically indicates the point at which the regulatory requirements trigger the need for visible placarding to enhance public safety and environmental protection.