Can a bus carrying passengers transport hazardous materials?

HAZMAT ON PASSENGER BUSES: Buses carrying passengers are PROHIBITED from carrying certain hazardous materials and strictly limited on others. PROHIBITED (cannot carry with passengers): Class A or B explosives; certain poisons (Division 2.3 poison gas, Division 6.1 poison); large quantities of certain hazmat; radioactive materials over limits; LIMITED amounts of some hazmat may be allowed under specific rules; WHY: The risk to passengers from a hazmat incident (fire, explosion, toxic release) is too great; passenger safety takes priority; SMALL EXCEPTIONS: Small-arms ammunition, emergency hospital supplies, drugs, and limited amounts of some materials may be permitted under regulations; FORBIDDEN: A bus must never carry more than a small total of allowed hazmat, and never the prohibited classes with passengers aboard; DRIVER RESPONSIBILITY: Know what passengers may be bringing aboard; refuse prohibited hazardous materials; the combination of passengers and hazardous materials is heavily restricted because a hazmat incident on a loaded bus could be catastrophic; this is tested on the passenger endorsement — passengers and dangerous hazmat generally cannot travel together.