Placard Requirements:
There are nine classes of Hazardous Materials. Vehicles transporting any quantity of explosives (1.1, 1.2, 1.3), Poison Gas, Dangerous When Wet, Organic Peroxide, Poison Inhalation Hazard or Radioactive Materials require placarding for even trace amounts. Vehicles transporting Other Explosives, Flamable Gas, Non-flammable Gas, Combustible, Flammable Solid, Spontaneously Combustible, Oxidizer, Organic Peroxide, Poison, Keep Away from Food or Corrosives require placards when transporting over 1,000 lbs. of the substance.