According to Lebanese authorities, the devastating explosion in the country’s capital on Tuesday would have been caused by ammonium nitrate, which is commonly used as a fertilizer.

A huge explosion in the port area took place in Beirut on Tuesday night, lifting a huge cloud of smoke into the city sky and causing a wave of pressure to destroy buildings. At least 70 people have died and thousands have been injured in the blast.

Odorless, crystalline ammonium nitrate has been the subject of several industrial explosions over the past decades. The explosion of a fertilizer plant in Texas, USA, in 2013, was due to ammonium nitrate. An explosion declared intentional killed 15 people.

The same substance was also to blame for the 2001 explosion at a chemical plant in Toulouse, France. A factory accident in Toulouse killed 31 people.

When ammonium nitrate is combined with fuel oils, it becomes a highly effective explosive that is widely used in the construction industry.

However, in addition to more legitimate uses, the same explosives are also used by rebel groups. Improvised explosives using ammonium nitrate have been used by the Taliban, among others.

Ammonium nitrate was also one of the ingredients in the bomb used in the 1995 Oklahoma City bombing. According to news channel CNN, 168 people died in the attack, 19 of whom were children. In addition, hundreds were injured.

In agriculture, ammonium nitrate fertilizer is used as granules that dissolve rapidly under the influence of moisture. This releases nitrogen from the fertilizer into the soil, which is crucial for growth.

A smaller explosion could ignite the reaction from ammonium nitrate

According to Tukes, ammonium nitrate is not a combustible substance, but it accelerates the combustion of other substances. Pure ammonium nitrate can also explode under certain conditions. The possibility of an explosion can be increased by strong heating, for example in a fire.

However, under normal storage conditions, it is difficult to ignite ammonium nitrate without the effect of high heat, Jimmie Oxley, a professor of chemistry at the University of Rhode Island, tells AFP news agency.

- If you watch the video (of the Beirut explosion), you see black smoke, you see red smoke, it was an imperfect reaction, he said.

- I assume there was a minor explosion that fueled the ammonium nitrate reaction, he goes on to point out that he has no information on whether the small explosion was an accident or something intentional.

Very strict rules have often been laid down for the storage of ammonium nitrate. For example, it should be kept away from fuels and heat sources. In many EU countries, calcium carbonate has to be added to ammonium nitrate to produce calcium ammonium nitrate, which is safer than ammonium nitrate alone.

In the United States, regulation was tightened considerably after the Oklahoma City bombing.

Despite the dangers of ammonium nitrate, its uses in the agricultural and construction industries have made it invaluable, Oxley says.

“We wouldn’t have this modern world without explosives, and we wouldn’t feed today’s population without ammonium nitrate fertilizer,” he said.

- We need ammonium nitrate, we just have to pay good attention to what we do with it.

Ammonium nitrate had been stored for six years

According to Lebanese Prime Minister Hassan Diab, about 2,750 tons of ammonium nitrate exploded in the port of Beirut, the capital of the country. According to the Prime Minister, it is not acceptable for 2 750 tonnes of ammonium nitrate to have been in storage for six years without taking into account the necessary safeguards.

According to AFP sources, there were two explosions, but only one major explosion has also been reported in many media outlets.

The country's health ministry said at least 73 people were killed and more than 3,700 injured in Beirut, according to AFP news agency, just before the turn of the day.

According to the New York Times, among others, the figures reported by the Department of Health would later have risen to at least 78 deaths and 4,000 injuries.