What is ammonium nitrate - the substance behind the explosion in Beirut

Lebanese Prime Minister Hassan Diab stated that the explosion in the port of Beirut on August 4 with catastrophic consequences was 2, 700 tons of ammonium nitrate stored in the port territory since 2014 with numerous violations.

Ammonium nitrate or ammonium nitrate (NH₄NO₃) is produced in the form of small porous granules and is one of the most widely used mineral fertilizers in the world. At the same time, under certain conditions, it becomes a component of explosives. What happened on August 4 in the port of Beirut?

Ammonium nitrate does not burn by itself. However, it can release oxygen, which accelerates combustion. Ammonium nitrate granules contribute to the creation of a higher concentration of oxygen than in the air around us. This is why it is effective in the production of explosives when mixed with oil and other fuels.

Ammonium nitrate

However, at sufficiently high temperatures, ammonium nitrate begins to decompose spontaneously with the formation of gases, including nitrogen oxides and water vapor, which provoked the explosion.

The decomposition of ammonium nitrate could be caused by an explosion due to a severe fire near its storage site, as was the case in Tianjin, China in 2015.

While the exact reasons for the tragedy in the port of Beirut are unknown, however, in the frames a few moments before the explosion, it is clear that there was a fire. When ammonium nitrate explodes, huge amounts of nitrogen oxides are formed. One of them, nitrogen dioxide (NO 2) - a gas with a heavy, unpleasant red odor was clearly visible in the video footage at the time of the explosion.