Ammonium perchlorate (AP) is produced by reaction between ammonia and perchloric acid. This process is the main outlet for the industrial production of perchloric acid. The salt also can be produced by salt metathesis reaction of ammonium salts with sodium perchlorate. This process exploits the relatively low solubility of NH4ClO4, which is about 10% of that for sodium perchlorate.[6]
Like most ammonium salts, ammonium perchlorate decomposes before melting:[citation needed]
4 NH4ClO4 → 4 HCl + 2 N2 + 5 O2 + 6 H2O
The combustion of AP is quite complex and is widely studied. AP crystals decompose before melting, even though a thin liquid layer has been observed on crystal surfaces during high-pressure combustion processes.[7] Strong heating may lead to explosions. Complete reactions leave no residue. Pure crystals cannot sustain a flame below the pressure of 2 megapascals (290 psi).[citation needed]
AP is a Class 4 oxidizer (can undergo an explosive reaction) for particle sizes over 15 micrometres and is classified as an explosive for particle sizes less than 15 micrometres.[citation needed]
The primary use of ammonium perchlorate is in making solid rocket propellants.[citation needed] When AP is mixed with a fuel (like a powdered aluminium and/or with an elastomeric binder), it can generate self-sustained combustion at pressures far below atmospheric pressure. It is an important oxidizer with a decades-long history of use in composite rocket propellants (including the Space Shuttle Solid Rocket Booster), military, amateur, and hobbyist high-power rockets, as well as in some fireworks.[citation needed]
Toxicity
Perchlorate itself confers little acute toxicity. For example, sodium perchlorate has an LD50 of 2–4g/kg and is eliminated rapidly after ingestion.[6] However, chronic exposure to perchlorates, even in low concentrations, has been shown to cause various thyroid problems, as it is taken up in place of iodine.[citation needed]
^ abHelmut Vogt, Jan Balej, John E. Bennett, Peter Wintzer, Saeed Akbar Sheikh, Patrizio Gallone "Chlorine Oxides and Chlorine Oxygen Acids" in Ullmann's Encyclopedia of Industrial Chemistry 2002, Wiley-VCH. doi:10.1002/14356007.a06_483
^Boggs, T. L. (1970). "Deflagration Rate, Surface Structure and Subsurface Profile of Self-Deflagrating Single Crystals of Ammonium Perchlorate". AIAA Journal. 8 (5): 867–873. Bibcode:1970AIAAJ...8..867B. doi:10.2514/3.5780.
^Kaye, Seymour M. (1 January 1978). Encyclopedia of Explosives and Related Items. PATR 2700(PDF). Picatinny Arsenal, New Jersey, USA: U.S. Army Research And Development Command: Tacom, Ardec: Warheads, Energetics And Combat Support Center. p. P-12. Retrieved 2 August 2025.
