You can carry any hazardous materials on your bus as long as they are properly labeled.
Most hazardous materials are prohibited on buses. However, certain hazardous materials (such as small-arms ammunition labeled "ORM-D") may be allowed on a bus if the packages are properly labeled. Don't allow any hazardous material on your bus until you first make sure that the rules allow it.
B Many hazardous materials cannot be carried on a bus.
C Shippers must mark each package of hazardous materials with the material’s name, ID number, and hazard label.
D Buses may carry small-arms ammunition labeled "ORM-D."