A placard is required for a combustible liquid at ___ pounds and more.

A placard is required for transporting combustible liquids when the total weight of the shipment reaches 1,001 pounds or more. This regulation is part of the Hazardous Materials Transportation Act, which aims to enhance safety and communication when transporting hazardous materials by requiring appropriate signage.

Combustible liquids are classified as materials that can be dangerous during transportation due to their flammable properties. Therefore, once the shipment surpasses 1,000 pounds, the risk associated with handling and transporting these liquids increases significantly, necessitating clear indicators for emergency responders and transport operators to recognize the potential hazards.

In this context, the other weight thresholds do not meet the criteria established by regulations. A placard is essential at the specified threshold to ensure compliance and promote safety throughout the transportation process.