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Which of the following is not commonly listed as a prohibited material on buses?

  1. Radioactive material

  2. Combustible metals

  3. More than 500lbs of allowed hazardous material

  4. More than 100lbs of solid class 6 poisons

The correct answer is: More than 500lbs of allowed hazardous material

The correct choice indicates that “more than 500lbs of allowed hazardous material” is not commonly listed as a prohibited material on buses. Buses have specific regulations concerning the transportation of hazardous materials that might pose a risk to passengers and the driver. While certain hazardous materials are strictly regulated or prohibited, there are cases where limited amounts of certain hazardous materials may be allowed. The limitation of allowing up to 500 pounds of hazardous material acknowledges that not all hazardous materials are equally dangerous and that some might be safe to transport within regulated limits. In contrast, radioactive materials, combustible metals, and significant quantities of solid class 6 poisons pose inherent risks during transportation, and as such, are generally prohibited due to their potentially dangerous nature, which can impact both the vehicle occupants and the general public. Understanding the nuances of these regulations is crucial for maintaining safety standards in commercial driving.