This kind of substances has a capability to emit easily oxygen to sustain combustion. In certain cases the materials of this kind can also cause spontaneous ignition and explosion. However they are not always combustible itself.

Peroxides are the organic substances inclined to exothermic decomposition at the normal or elevated temperature. Such decomposition can lead to formation of harmful or flammable gases or vapors. Decomposition can begin under the influence of heat, because of the contacts with impurity, by means of friction or blow. Its speed increases with temperature rise and depends on composition of organic peroxide. 

  • Division 5.1: Oxidizing agents, flammable substances which may cause or contribute to combustion, generally by yielding oxygen.
  • Division 5.2: Organic peroxides, either in liquid or solid form. Self-decomposing substances which may cause or contribute to combustion. Decomposition can begin under the influence of heat, because of the contacts with impurity, by means of friction or blow.