Ammonium Nitrate Facts and Uses

What You Need to Know About Ammonium Nitrate

Cold pack placed on injured ankle to reduce swelling. Cold pack contains ammonium nitrate and water, which when mixed together produce an endothermic reaction that is cold.
Cold packs are made using Ammonium Nitrate. Matt Meadows / Getty Images

Ammonium nitrate is the nitrate salt of the ammonium cation. It may be considered the ammonium analog to potassium nitrate or saltpeter. Its chemical formula is NH4NOor N2H4O3. In pure form, ammonium nitrate is a crystalline white solid that readily dissolves in water. Heat or ignition readily cause the substance to ignite or explode. Ammonium nitrate is not considered toxic.

Options for Obtaining Ammonium Nitrate

Ammonium nitrate may be purchased as a pure chemical or collected from instant cold packs or some fertilizers. The compound is most commonly prepared by reacting nitric acid and ammonia. It's also possible to prepare ammonium nitrate from common household chemicals. While it is not difficult to make ammonium nitrate, it is dangerous to do so as the chemicals involved can be hazardous. In addition, it can easily become explosive when mixed with fuels or other chemicals.

Ammonium Nitrate Uses and Sources

Ammonium nitrate is a chemical compound used in agriculture as a fertilizer, to make pyrotechnics, as an ingredient in cold packs, and for science demonstrations. It's also used to create controlled explosions in mining and quarrying. It was once mined as a natural mineral (niter) in the deserts of Chile, but it is no longer available except as a man-made compound. Because ammonium nitrate may be misused, it has been phased out in many countries.