Science, Tech, Math › Science Ammonium Nitrate Facts and Uses What You Need to Know About Ammonium Nitrate Share Flipboard Email Print Cold packs are made using Ammonium Nitrate. Matt Meadows / Getty Images Science Chemistry Projects & Experiments Basics Chemical Laws Molecules Periodic Table Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Anne Marie Helmenstine, Ph.D. Chemistry Expert Ph.D., Biomedical Sciences, University of Tennessee at Knoxville B.A., Physics and Mathematics, Hastings College Dr. Helmenstine holds a Ph.D. in biomedical sciences and is a science writer, educator, and consultant. She has taught science courses at the high school, college, and graduate levels. our editorial process Facebook Facebook Twitter Twitter Anne Marie Helmenstine, Ph.D. Updated December 22, 2018 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 NH4NO3 or 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.