Question Buses must never carry: Answers Tear gas. Any amount of solid Class 6 poisons. Bottled oxygen. Emergency hospital supplies. Explanation Buses may never be used to transport radioactive materials. Division 2.3 poison gas, liquid Class 6 poisons, tear gas, and irritating materials are also not permitted to be carried by bus. This questions appears in the following tests: Illinois Charter New Jersey Passenger New York Passenger Pennsylvania Passenger