In this case, according to Lebanese officials, about 2,750 tons of ammonium nitrate had been stored in a warehouse in the port of Beirut, just a few minutes walk from the city’s shopping and nightlife district, since it was confiscated in 2014.
Prime Minister Hassan Diab said the chemical had been stored for the past six years “without precaution” and promised an investigation.
It is not yet clear what caused the warehouse in Beirut’s port to ignite with such fatal results on Tuesday night.
“Ammonium nitrate is … relatively safe by itself, although it is a strong oxidant, but very dangerous when contaminated with any form of fuel, such as oil or organic matter, even in just a few percent,”
“In the presence of heat, such a mixture can easily lead to catastrophic results,” he added.
Ammonium nitrate is not flammable in itself, said Associate Professor Stewart Walker of the School of Forensic Science, Environment and Analytical Chemistry at Flinders University in Adelaide, Australia, CNN reported.
“In this case, it appears that there was a fire and that the fire caused the ammonium nitrate that had been stored to burn, and when it is in a cramped space, it releases very hot gas,” he said.
“Because the gas takes up a higher volume than the solid material, there is a pressure build-up and due to the released heat, the hot gas is higher in volume, so you get to the point that when it is limited it will suddenly explode and will release that pressure in a shock wave, “Walker added.
Videos from Tuesday’s explosion show that “the fire starts with a gray-white cloud and then, at the explosion, there is a large column of red-orange-brown smoke and a large white” mushroom cloud “, which is the shock wave, Walker said.
The red-orange-brown smoke is characteristic of nitric oxide, a toxic gas released from ammonium nitrate, he said.
Has this happened before?
This is not the first time ammonium nitrate, which is reasonably cheap to manufacture, has been involved in deadly industrial explosions.
Perhaps the closest comparison, in terms of scale, is an explosion in Texas City in 1947. The fire caused an explosion and further fires that damaged more than 1,000 buildings and killed nearly 400 people, according to the Texas Historical Association website.
In perspective, this explosion triggered 2,300 US tons (approximately 2,087 tons) of ammonium nitrate, according to US Homeland Security.
“Poorly stored ammonium nitrate is notorious for explosions – for example in Oppau, Germany; in Galveston Bay, Texas; and most recently in the West in Waco, Texas; and Tianjin in China,” Andrea Sella, professor of inorganic chemistry at University College London, said. Science Media Center.
“This is a catastrophic regulatory failure because ammonium nitrate storage regulations are usually very clear. The idea that such a quantity would have been left unattended in six years of beggars’ beliefs and was an accident waiting to happen.”
Were other materials involved in Beirut?
The magnitude of the blast, as well as Lebanon’s troubled history, has led to speculation that military explosives may have been involved.
US President Donald Trump added to the confusion when he referred to the incident in an “attack”, although US Department of Defense officials told CNN afterwards that there was no indication that this was the case. Lebanese officials also raised concerns with U.S. diplomats about the use of the phrase “attack,” two State Department officials said.
Former British Army Major Chris Hunter, an expert on fertilizer bombs and explosives disposal, said he was “almost certain” that the main detonation was caused by an “industrial accident.”
Hunter, who continues to work in Iraq and Syria to train bomb disposal crews and was involved in operations to prevent a fertilizer bomb plot in London a few years ago, has seen many videos of the explosions.
“You can see an intense fire in the early stages, plus what could be fireworks or ammunition exploding. This is the type of heat source that would be needed to cause a large amount of ammonium nitrate to explode. It would normally burn but if ignited “Through intense fire, the white cloud that characterized this explosion is what we expect from ammonium nitrate,” he said.
“If the reports of 2,700 tonnes of the chemical are accurate, it is also consistent with the extent of an explosion and the damage,” he added.
How should ammonium nitrate be stored?
Past disasters have led to improved regulations for the safe storage of ammonium nitrate – a valuable inorganic fertilizer that has helped feed the world’s growing population – Walker said; such rules mean that it tends to be kept away from population centers.
“Both of these things will be questioned in the investigation of the Beirut explosion, because they had such a large amount of ammonium nitrate, which may not have been stored properly, and in an area where there are a large number of people,” he said.
Safe storage would mean keeping ammonium nitrate away from any source of ignition, keeping it away from all combustibles and keeping it in small enough containers, far enough away from each other, that if ignited it would not spread to the others, he said.
Given its potentially dangerous nature, governments usually restrict access to ammonium nitrate and require people to have a license to purchase it. Breivik, the Norwegian terrorist, was able to acquire and store it because he had a small farm, Walker explained.
As a result of these precautions, accidents occur more often when the chemical is in transit, either in trucks or by ship, Walker added.
Two such incidents have occurred in Queensland, Australia, he said. In 2014, a truck with ammonium nitrate exploded in Wyandra after rolling and destroying a bridge. And in 1972, three people were killed in Taroom when a truck carrying ammonium nitrate exploded after experiencing an electrical fault and fire.
Who produces it?
Russia is the world’s largest producer of ammonium nitrate, according to the United Nations Food and Agriculture Organization.
“It’s a matter of having equal terms between European producers and Russian producers,” Antoine Hoxha, chief technical officer of Fertilizers Europe, told CNN.
“Dumping is not a fair trade: there are international agreements on this. If there is a practice of dumping and it is verified, they will take steps to restore a game plan,” he said. The EU has applied the measures on a rolling basis and most recently reduced them somewhat in 2018.
Ammonium nitrate production is subject to stringent test measures in Europe, which Hoxha says were shaken after a 2001 explosion in Toulouse, France that killed dozens.
“You physically abuse the product by heating and cooling it, to really change its substance and to simulate that it is mistreated or stored or heated and cooled, which can happen under extreme storage conditions,” said Jo Gilbertson, Fertilizer Sector Manager at the UK Agricultural Industry Association, told CNN.
“We are deliberately abusing it and then trying to blow it up,” he said, adding that the same standards may not be applied outside the EU.
“It’s an industry where you can never be self-sufficient,” Gilbertson added. “The product we have with us is extremely safe when you take care of it. But if you do not take care of it, it is very easy to make a mistake.”