Ammonium Nitrate Explosions: Connecting Delhi's Red Fort Blast and Beirut's Catastrophic Incident

Ammonium nitrate alone is not classified as an explosive, but can become deadly when combined with other substances.

The Delhi car explosion that claimed nine lives on Monday is being investigated with a theory that it may have been accidental. Authorities are exploring whether the suspect, Umar Mohammad, unintentionally triggered the explosion while transporting explosives in his vehicle.

This incident bears striking similarities to the 2020 Beirut disaster, one of history's largest non-nuclear explosions, which devastated more than half the city. The Lebanese capital's catastrophe occurred when approximately 2,750 tonnes of improperly stored ammonium nitrate accidentally detonated.

Recently, authorities confiscated 2,900 kg of bomb-making materials, including 350 kg of ammonium nitrate, along with timers, assault rifles, handguns, and ammunition from Mujammil Shakeel's residence, a medical professional at Al-Falah Hospital in Haryana's Faridabad. Investigators believe Mujammil and Umar were connected.

Authorities now suspect Umar was transporting an undetermined quantity of Ammonium Nitrate Fuel Oil (ANFO) - a common industrial explosive created by combining porous ammonium nitrate with fuel oil - in his Hyundai i20 when it exploded near Red Fort metro station's gate number one.

Initial investigations revealed no crater formation at the blast site, which typically occurs with high-intensity explosive devices. The absence of projectiles suggests the device wasn't configured to maximize damage.

These findings led investigators to theorize that Umar may have "panicked" following the arrest of two associates - believed to be key members of a Faridabad-based Jaish-e-Mohammed terror cell - and accidentally triggered the explosion while relocating the explosive material.

The devastating Beirut explosion occurred on August 4, 2020, at 6:07 pm when a fire erupted in a large port hangar storing fireworks and approximately 2,750 tonnes of ammonium nitrate that had been improperly stored for years. The resulting explosion killed at least 218 people and injured 7,000 others.

This catastrophic event ranks among the largest non-nuclear explosions ever recorded, causing extensive damage throughout the city with infrastructure losses estimated at over $10 billion and displacing more than 300,000 residents.

Investigators later discovered the ammonium nitrate had been stored in the hangar for over six years after Lebanese Port authorities seized it from a Moldova-flagged vessel traveling from Georgia to Mozambique.

The Rhosus merchant ship, owned by a Russian businessman, was forced to dock in Beirut due to technical difficulties at sea. Lebanese authorities subsequently impounded the vessel for unpaid port fees, and in 2014, its cargo was unloaded and stored in a port warehouse.

Despite numerous safety warnings sent to high-ranking officials in subsequent years, no action was taken.

Ammonium nitrate is an odorless, white crystalline chemical commonly used in fertilizer and explosive production. It functions as a powerful oxidizer and, under specific conditions, can cause massive explosions through rapid chemical decomposition.

The decomposition reaction in an ammonium nitrate explosion produces nitrous oxide and water vapor that expand rapidly (up to 1,000 times the initial volume), generating a supersonic shockwave causing extensive physical damage. The explosion also releases harmful gases, including nitrogen oxides (characterized by a distinctive red-orange nitrogen dioxide plume) and ammonia, posing health risks to nearby populations.

This reaction generates considerable heat, with temperatures reaching up to 2,000 degrees Celsius in proximity to the blast.

However, ammonium nitrate by itself is not considered explosive. It requires mixing with a secondary substance - fuel oil in the Red Fort bomb case - and an external detonation trigger to explode.