What are some hazardous materials you CANNOT transport by bus?

When transporting hazardous materials, specific regulations govern what can and cannot be carried by different types of vehicles, including buses. The correct choice focuses on the classification of hazardous materials labeled as ORM-D (Other Regulated Material-Domestic), which includes items like ammunition. These materials can be categorized under regulations that prohibit their transport in passenger buses due to safety concerns related to potential accidents.

Ammunition and similar items pose risks such as explosive potential or fire hazards, which can endanger passengers and the vehicle itself. The prohibitory regulations ensure that certain high-risk materials are not transported in a manner that compromises safety, particularly in a passenger-carrying vehicle like a bus, where the presence of hazardous materials could have catastrophic consequences.

Other materials listed, while they may have their own risks, do not fall under the same strict prohibitions for buses as ORM-D items do. Fuels like gasoline and acetone may be regulated but can be transported under specific conditions in other vehicles. Helium and oxygen can often be transported, as long as they are properly packaged and labeled; and flammable hair spray, while hazardous, may also have regulations that allow it to be carried under careful guidelines.