Chennai, Aug 06: Two days after unsafely stored ammonium nitrate that killed at least 135 people and injured thousands in Beirut, Lebanon, concerns have been raised about stored nearly 700 tonnes of the explosive ammonium nitrate for years under the custody of the Customs Department, outside Chennai, Tamil Nadu.
Referring the fatal Beirut tragedy, PMK chief Dr Ramadoss demanded safe disposal of the explosive chemical and its safe use in making other products.
"There is a risk of a similar explosion. To avert that the explosives ought to be disposed safely and used for manufacture of fertiliser and other needs," Ramadoss tweeted.
But Chennai port officials have denied and said the pile of explosives is no longer stored in the harbor.
"Around 36 containers, each with around 20 tonnes of ammonium nitrate, have been shifted long time ago and now they are under the Customs Department's control," an officer from Department said.
What is ammonium nitrate and why it is explosive
Ammonium nitrate is a chemical compound containing the element nitrogen, as well as hydrogen and oxygen, and is commonly used in agriculture as fertilizer. Nitrogen is an essential element for plants and ammonium nitrate is particularly good, compared with other fertilizers.
Ammonium nitrate is also an explosive compound and is used around the world in mining and construction operations in the times of detonations.
The chemical is highly stable under normal conditions.
But it can explode after exposure to contaminants or fuel oil and then heated.
If the chemical heated with above 170 degrees Fahrenheit, it begins to undergo decomposition. With rapid detonation, chemical reaction can occur that converts ammonium nitrate to nitrogen and oxygen gas and water vapor. And the process releases huge amounts of energy.
Though burning ammonium nitrate in an open field is not likely to result in an explosion in confined space high energy explosion can occur.
In the Beirut explosion, not all of the ammonium nitrate used exploded in the explosion.
Some of it decomposes slowly creating toxic gases like nitrogen oxides which are responsible for the red-brown plume of smoke seen in the aftermath of the explosion, says specialists.
As ammonium nitrate is potentially explosive, countries and unions impose strict regulations on storing and processing it.
"It is generally kept under controlled conditions and modified volumes to minimize chances of explosion," says Brent Kaiser, a plant biologist at the University of Sydney.
Notably, in 2015, explosions partly caused by the detonation of around 800 tons of ammonium nitrate rocked the Beijing port in China, killing 173 people.
In 1947, the worst industrial accident in US history that killed 581 people when a ship in the harbor of Texas City, Texas, carrying approximately 2,300 tons of ammonium nitrate caught fire.
Notably about 2,750 tonnes of ammonium nitrate were stored in a Beirut port warehouse that exploded on Tuesday.