[7] Ammonium nitrate is found as the natural mineral gwihabaite (formerly known as nitrammite)[9] – the ammonium analogue of saltpetre (mineralogical name: niter)[10][11] – in the driest regions of the Atacama Desert in Chile, often as a crust on the ground or in conjunction with other nitrate, iodate, and halide minerals.

One practical consequence of this is that ammonium nitrate cannot be used as a solid rocket motor propellant, as it develops cracks.

Stabilized ammonium nitrate (PSAN) was developed as a solution to this and incorporates metal halides stabilisers, which prevent density fluctuations.

Ammonium nitrate's advantage over urea is that it is more stable and does not rapidly lose nitrogen to the atmosphere.

[18]: 1  It is used in coal mining, quarrying, metal mining, and civil construction in undemanding applications where the advantages of ANFO's low cost, relative safety, and ease of use matter more than the benefits offered by conventional industrial explosives, such as water resistance, oxygen balance, high detonation velocity, and performance in small diameters.

In November 2009, the government of the North West Frontier Province (NWFP) of Pakistan imposed a ban on ammonium sulfate, ammonium nitrate, and calcium ammonium nitrate fertilizers in the former Malakand Division – comprising the Upper Dir, Lower Dir, Swat, Chitral, and Malakand districts of the NWFP – following reports that those chemicals were used by militants to make explosives.

Due to these bans, "Potassium chlorate – the material which allows safety matches to catch fire – has surpassed fertilizer as the explosive of choice for insurgents.

In 2021, King Abdullah University of Science and Technology in Saudi Arabia conducted experiments to study the potential for dissolving ammonium nitrate in water for off-grid cooling systems and as a refrigerant.

[20] It was once used, in combination with independently explosive "fuels" such as guanidine nitrate,[21][22] as a cheaper (but less stable) alternative to 5-aminotetrazole in the inflators of airbags manufactured by Takata Corporation, which were recalled as unsafe after killing 14 people.

[25][26][27] Pure ammonium nitrate does not burn, but as a strong oxidizer, it supports and accelerates the combustion of organic (and some inorganic) material.

While ammonium nitrate is stable at ambient temperature and pressure under many conditions, it may detonate from a strong initiation charge.

Molten ammonium nitrate is very sensitive to shock and detonation, particularly if it becomes contaminated with incompatible materials such as combustibles, flammable liquids, acids, chlorates, chlorides, sulfur, metals, charcoal and sawdust.

[30][25] Contact with certain substances such as chlorates, mineral acids and metal sulfides, can lead to vigorous or even violent decomposition capable of igniting nearby combustible material or detonating.

For example, in Australia, the Dangerous Goods Regulations came into effect in August 2005 to enforce licensing in dealing with such substances.

Ammonium nitrate decomposes, non-explosively, into the gases nitrous oxide and water vapor when heated.

[40] Large stockpiles of the material can also be a major fire risk due to their supporting oxidation, a situation which can easily escalate to detonation.