Class 4: Flammable Solids

Materials in Class 4 consist of flammable solids that are:

  • Self-reactive substances
  • Solid desensitized explosives
  • Substances liable to spontaneous combust
  • Materials that, when in contact with water, emit flammable/toxic gases
A red and white vertically striped diamond placard with a black flame at the top, the words flammable solid in the middle, underneath that the number 4.