Explosive materials are used for many military and industrial purposes. These are chemicals and mixtures which, when affected by strong mechanical force (hitting, shock, friction) or starting ignition, suddenly transform to gases of large volume through an extremely rapid oxidizing reaction (e.g., 1,000-10,000 m/s). The volume of these gases is the multiple of the volume of the explosive material already exploded, and they will exert very high pressure on the surroundings. During an explosion, high temperatures can arise (2,500-4,000 °C) that promote the ignition of the combustible materials in the zone of explosion.
Manufacture, transport and storage of the various explosive materials are governed by rigorous requirements. An example is NFPA 495, Explosive Materials Code. Besides the explosive materials used for military and industrial purposes, the inductive blasting materials and pyrotechnical products are also treated as hazards. In general, mixtures of explosive materials are often used (picric acid, nitroglycerin, hexogene, etc.), but mixtures of materials capable of explosion are also in use (black powder, dynamite, ammonium nitrate, etc.). In the course of acts of terrorism, plastic materials have become well-known, and are, in essence, mixtures of brisant and plasticizing materials (various waxes, Vaseline, etc.).
