PHYSICAL APPEARANCE/COLOR – Colorless or white to gray hygroscopic crystals
INITIATION – Lead azide 0.20 g, Tetryl 0.25 g along with a substantial booster
SENSITIVITY – Very low, unaffected by friction, impact, or shock, unaffected by 7.62mm (.30 cal.) rifle bullet impact, an impact test with a 2 kg (4 lb 6 oz) weight requires a drop of 221 cm (87 in) to initiate a reaction
STABILITY – Extremely hygroscopic, Stable in storage when kept very dry
DETONATION VELOCITY – 2,700 m/s (8,858 fps)
RE FACTOR (BRISANCE) [TNT=1.0] – 0.42
TOXICITY – Very low toxicity
MELTING POINT – 169o C (334o F.), decomposes at 210o C.(410o F.)
IGNITION POINT – 465o C. (869o F)
SOLUBILITY – Very soluble in water, 213 g AN per 100 g water at 25o C. (77o F.)
APPLICATIONS – PRINCIPLE USES – Used as a major component of explosive mixtures
Though first discovered in 1659, Ammonium nitrate was not considered as an explosive until 1867, when it was included in a formulation for dynamite. When under sufficient confinement and pressure, straight Ammonium nitrate can be made to detonate. But the material is so insensitive that it cannot be easily used as a stand-alone explosive unless initiated by a relatively large booster charge. Normally, Ammonium nitrate is combined with other ingredients to make up an explosive mixture such as binary explosives, some dynamites, and ANFO (Ammonium nitrate/Fuel oil). In the older US military cratering charge, the Ammonium nitrate main explosive is faced against a large central booster explosive of TNT to insure detonation. The low shattering effect (brisance) of Ammonium nitrate makes it most suitable for use when a heaving or pushing force is needed, such as in mining, quarrying, or making craters as obstacles. When combined with Nitromethane, Ammonium nitrate makes the commercial binary explosive Kinepak. In Kinepak, the Ammonium nitrate is considered an oxidizing rather than an explosive component of the mixture. The Nitromethane is considered a flammable liquid for the purposes of transportation and storage. The unmixed component can be more easily transported and stored prior to use than a standard high explosive. When mixed with other fuels, such as standard home heating fuel oil, Ammonium nitrate makes the explosive mixture known as ANFO. Since Ammonium nitrate can be obtained in bulk quantities much more easily than conventional explosives, ANFO has become an explosive of choice for terrorist use in improvised explosive devices when a very large explosion is desired.
