What color background is used for a Class 7 (radioactive) placard?

A Class 7 (radioactive) placard features a yellow background. This color is specifically chosen due to its high visibility and association with caution, which is particularly important given the hazards posed by radioactive materials. The design typically includes specific symbols and text indicating the material's radioactive nature, making it essential for ensuring safety and alerting responders and the public to the potential risks.

In the context of hazardous materials, the standardized use of color coding for placards helps to convey critical information quickly and effectively, aiding in emergency response and safety measures. The other colors mentioned do not represent Class 7 placards, reinforcing the need for consistent use of yellow for radioactivity to prevent confusion on the transportation of hazardous materials.