By Alaa Al Mikkawi

Photo by ANWAR AMRO/AFP via Getty Images

“Chemistry ought to be not for chemists alone.” – Miguel de Unamuno

Standing there.. praying .. I felt the ground shake. Thinking it was a minimal earthquake, I resumed prayer until a booming sound struck out of nowhere sending shivers down my spine… Directly, I turned to my bestfriend and her family in confusion asking what just happened. All of us rushing to the balcony we saw red smoke covering the wide blue sky. At that moment, we knew an explosion just occurred in dear Lebanon. Assumptions ran our minds … presuming who might be the new target now. The next thing we knew, we were calling loved ones making sure they were okay. Lives paused in these few devastating minutes awaiting explanations and clarifications. Reported on the TV, the Beirut port blew up, shaking the whole city. Homes were damaged, glasses were shattered, hearts were broken, faces became heart-breaking.

            Our story begins here…

A group of final-year analytical chemistry students meeting online found themselves in a situation that none could have forseen: discussing their own safety and survival through the lens of their discipline. So they started to read into the chemistry of the explosion, processing what had happened in their own words.

The incident has been a catastrophe that the whole world spoke of. It caused the devastating destruction in neighbouring areas, where sadly some were only salvageable. This sprung much attention to the core of the problem. A few hours after the explosion, officials announced it was due to a reaction between ammonia and nitric acid (forming ammonium nitrate). However, the fundamental chemical aspect was rarely addressed in an appropriate and complete manner in the countless news articles that have been written to describe and analyze what happened.  

In order for a fire/explosion like this to occur, the substances need to be confined in a small area. A question that must be tackled here is: Why did ammonium nitrate react so vigorously and lead to such a devastating explosion? In order to answer this question a deep dive into the reaction and decomposition of ammonium nitrate is required.

The first thing that comes to mind when talking about a chemical substance is its chemical formula. Ammonium nitrate is formed from ammonium NH⁴⁺and nitrate NO^3-giving the molecular formula, NH₄NO₃. It was first synthesized in 1659 by a German chemist. Back then, NH₄NO₃was mainly used for agricultural needs in which its most abundant benefit is stimulating plant growth. It was not until World War I (1914) that Ammonium Nitrate was used to develop explosives. Weaponry design often coupled NH₄NO₃ with TNT to produce cheaper bombs. Ever since, the ammonium nitrate has been responsible for at least 30 disasters: some were accidental, and others intentional. An overlooked fact in this reaction was the presence ofcatalytic agents—substances used to increase the rate of the reaction. Furthermore, the driving property that makes ammonium nitrate an explosive material is that it belongs to a class of oxidizers. An oxidizer is a substance that has the ability to accept electrons from other substances. As a result of that, oxygen molecules become more concentrated in a specific place thus more heat can be contained for a longer period of time causing it to increase its flammability. Nevertheless, it is important to note that ammonium nitrate decomposition includes multiple dangerous gases if dealt in a sensitive environment. 

Storage of ammonium nitrate plays a major role in keeping the substance stable thus safe to handle. Storing this chemical for a long period of time (or as happened in Beirut’s port, for a period of 7 years) might facilitate the process of degradation causing it to be more volatile and dangerous. Ammonium nitrate can degrade from heat, for instance, to produce nitrous oxide (N₂O) and water. Correspondingly, metal corrosion, which is the destruction of metals by chemicals or/and their surroundings, is bound to happen in this poor storage condition. This leads to the production of explosion catalysts (chlorides and chromates for example). These facilitate ammonium nitrate to burn faster. That being said, contamination of ammonium nitrate could have easily caused an even more powerful explosive. Moreover, according to the Lebanese authorities, ammonium nitrate was not stored on its own in the warehouse where it was stored; Warehouse 12 also contained fireworks which have contaminated the substance stored. As a result, storage facility managers must reconsider their guidelines and provide safety data sheet for each stored chemical in order to ensure security to the people and their country. In Lebanon, this caught the eye of many offices and agencies of the UN which encouraged them to respond to the aftermath. The UN urges the people in charge to respect and abide by rules and regulations put by International Maritime Dangerous Goods Code and International Labour Organisation (ILO) code of practice on safety and health in ports. Still it is not enough to only state the rules, but the government should abide by them otherwise there will be gaps.

Since all the products following the NH₄NO₃burn were in a gaseous phase, a large amount of pressure traveled outwards at a supersonic speed causing the shockwaves emitted after the initial impact of the blast. These shockwaves were visible in the form of a mushroom cloud. Following that cloud was a reddish-orange smoke making its way into the atmosphere. This color signified the presence of nitrogen dioxide (NO₂) which is one of the byproducts of NO^3-(a chemical often associated with air pollution). The release of NO₂ in the air presents a risk to the people especially with respiratory issues causing severe damage to the extent of death. In fact, the whole area near the explosion should have been evacuated for two days as said by some scientists.

That being said, it is ironic how a dozen of undergraduate chemists can provide enough background about the topic of interest—ammonium nitrate—just from their background and knowledge and a bit of searching online, yet a whole ‘supposedly’ grown-up government was not even capable of correctly handling such a substance. This begs the question: Why is our government so incompetent of such essential skills? 

What happened in Lebanon was sadly not the first NH₄NO₃ catastrophe. In 1921, more than 500 people were killed after the detonation of about 4,500 tons of ammonium nitrate in Oppau, Germany. In 1947, 581 people were killed when more than 2,000 tons of the chemical detonated at Galveston Bay.In 2015, an explosion in Tianjinkilled 173 people after flammable chemicals and ammonium nitrate were stored together at a chemicals factory in eastern China.

Each individual living in Lebanon at that moment experienced this and all shared one fear, one rage. Now people know what this explosion was made of, maturing their ideas towards it. This story will remain indefinitely on the tongues of Lebanon from the materialistic aspect to the core chemical aspect. Despite the challenges, the land and its citizens will rise again from the ashes fuelled with one love.

 References:

– Sarah Gibbens,(2020), The deadly history of ammonium nitrate, the explosive linked to the Beirut blast, from https://api.nationalgeographic.com/distribution/public/amp/science/2020/08/deadly-history-ammonium-nitrate-explosive-linked-to-beirut-blast

– Laura Howes,(2020), The Chemistry behind the Beirut explosion, from https://cen.acs.org/safety/industrial-safety/chemistry-behind-Beirut-explosion/98/web/2020/08

– Rehab Abdalmohesen,(2020), ‘You can’t imagine the disaster we’re living in’:Lebanon’s researchers struggle to cope with explosion aftermath, from https://www.nature.com/articles/d41586-020-02437-8

– Gabriel da Silva,(2020), What is Ammonium Nitrate, the Chemical That Exploded in Beirut?, from https://www.scientificamerican.com/article/what-is-ammonium-nitrate-the-chemical-that-exploded-in-beirut/

– Tom Edgingtion,(2020),Beirut Explosion: What is ammonium nitrate and how dangerous is it?, from https://www.bbc.com/news/explainers-53664064

– Han, Z., Sachdeva, S., Papadaki, M., & Mannan, S. (2015, December 17). Effects of inhibitor and promoter mixtures on ammonium nitrate fertilizer explosion hazards. Retrieved September 13, 2020, from https://www.sciencedirect.com/science/article/abs/pii/S004060311500492X

– Al Arabiya, (2020), Beirut Explosion Equivalent of 200 to 300 tons of high explosives, from https://english.alarabiya.net/en/News/middle-east/2020/08/15/Beirut-port-explosion-equivalent-of-200-to-300-tons-of-high-explosives-Experts.html

– Rachel Lance,(2020),The Tragic Physics of the Deadly Explosion in Beirut, from https://www.wired.com/story/tragic-physics-deadly-explosion-beirut/

– Malak Jaafar,(2020), How can the UN help prevent another Beirut disaster?, from https://news.un.org/en/story/2020/08/1070582