Over 4,000 people have been injured and at least 100 people have lost their lives due to the explosion in Beirut, Lebanon that took place on Tuesday. 

Hassan Diab, the PM of Lebanon, stated that the massive explosion was supposedly caused by 2,750 tons of ammonium nitrate that was stored in a warehouse. 

This blast sheds light on the deadly potential of this common agricultural chemical. So, lets understand what ammonium nitrate is and how deadly this chemical can be if preventive measures are not taken.

Source: www.dnaindia.com

1. What is ammonium nitrate?

Ammonium nitrate is a industrial chemical that is mainly used for fertiliser as it is a good source of nitrogen for plants. This chemical is relatively stable under most conditions and is inexpensive to manufacture, making it a popular alternative to other, more expensive nitrogen sources.

Source: www.telegraph.co.uk

It is also one of the main components used in mining explosives, quarrying and civil construction. And, it accounts for 80% of all the industrial explosives used in U.S.

Ammonium nitrate is not dangerous or explosive on its own but, under certain circumstances it can be deadly. Gabriel da Silva, a senior lecturer in chemical engineering at the University of Melbourne said:

This chemical only ignites under the right circumstances, and these are difficult to achieve. You need extreme circumstances to set off an explosion. 

You see, Ammonium nitrate is an oxidiser, drawing oxygen to a fire, therefore making it much more volatile and intense. This is one of the major reasons why most countries have regulations to control its storage to make sure it is safe. 

So, what makes ammonium nitrate explosive?

Ammonium nitrate is classified as an 'energetic material.' This chemical generates heat as it decomposes and if there is sufficient quantity of this chemical, it can generate enough heat to catch fire and keep the fire going, without needing an external catalyst such as a flame. 

And, as it burns, this material goes through chemical changes that lead to the production of oxygen which is required to fuel the fire. 

When it heats up, the chemical fuses together, creating a seal or plug. As the space behind the plug continues to heat, the gases get trapped and have nowhere to go. 

This creates extreme pressure and the gas eventually breaks through the seal and the force of that triggers an explosion. 

Da Silva thinks this is exactly what has happened in Beirut. He says: 

While the chemicals in the air should dissipate fairly quickly, lingering pollutants can cause problems later, for example if they acidify rain. If you look at the smoke that came from the blast it’s this kind of blood red colour . That’s because of the nitrogen oxide air pollutants in it. 

Speaking about the incident Prime Minister Hassan Diab said:

It is unacceptable that a shipment of 2,750 tonnes of ammonium nitrate has been present for six years in a warehouse, without taking preventive measures. 

Two back to back explosions sent shockwaves across the city of Beirut, shattering windows and causing apartment balconies to collapse with in the radius of 10 kms. The blast took place in the city's port area.