Delhi blast: What is Ammonium Nitrate? Dangerous material once led to massive explosion in Lebanon
- MM24 News Desk
- 25 minutes ago
- 3 min read
A car explosion near New Delhi's Red Fort on November 10, 2025, killed 13 people using a suspected ammonium nitrate-fuel oil (ANFO) mixture, the same compound that caused the 2020 Beirut explosion killing over 200 people. Reports revealed that ammonium nitrate was possibly mixed with fuel oil to trigger the Delhi blast. The chemical combination has proven catastrophically lethal throughout history.
Understanding Ammonium Nitrate
Ammonium nitrate (NH₄NO₃) is a white crystalline chemical compound primarily used as a high-nitrogen fertilizer, according to PubChem, the National Library of Medicine's chemical database. The compound consists of ammonium ions and nitrate ions, making it highly soluble in water and an excellent source of nitrogen for agricultural applications.
At room temperature, ammonium nitrate appears as colorless crystals or white granules. It has a molecular weight of 80.043 g/mol and melts at approximately 169.6 degrees Celsius (337.3 degrees Fahrenheit), according to PubChem. The compound is odorless and has a slightly bitter taste.
While ammonium nitrate itself is relatively stable under normal conditions, it becomes a powerful oxidizing agent when subjected to heat or contamination. This property makes it useful in agriculture but potentially deadly in the wrong hands.
The ANFO Connection
Ammonium nitrate becomes particularly dangerous when mixed with fuel oil, creating what's known as ANFO (Ammonium Nitrate-Fuel Oil). This mixture transforms an agricultural fertilizer into a powerful explosive compound that has been used both in legitimate mining operations and, tragically, in terrorist attacks.
According to India's Petroleum and Explosives Safety Organisation (PESO), ammonium nitrate is classified under the Ammonium Nitrate Rules, 2012, which regulate its manufacture, import, export, transport, possession for sale, and use. The substance requires careful handling and storage due to its explosive potential when contaminated or heated.
The compound works as an explosive because ammonium nitrate is an oxidizer – it provides oxygen to fuel a chemical reaction. When mixed with fuel oil (which provides the fuel), and triggered by a detonator, the mixture undergoes rapid decomposition, releasing enormous amounts of energy in the form of heat and gas expansion.
The Beirut Catastrophe
The deadliest recent example of ammonium nitrate's destructive power occurred on August 4, 2020, in Beirut, Lebanon. A massive explosion at the city's port killed more than 200 people, injured over 6,000, and left approximately 300,000 people homeless.
The explosion was caused by approximately 2,750 tonnes of ammonium nitrate that had been stored unsafely in a warehouse for six years. The blast created a crater 140 meters wide and was felt as far away as Cyprus, 240 kilometers across the Mediterranean Sea.
The force of the Beirut explosion was equivalent to between 500 and 1,100 tonnes of TNT, according to experts cited by BBC. Seismologists registered it as a 3.3 magnitude earthquake. The blast wave destroyed or damaged virtually every building within a 10-kilometer radius.
Why Ammonium Nitrate Explodes
Under normal conditions, ammonium nitrate is relatively safe. However, several factors can trigger explosive decomposition. High temperatures above 210 degrees Celsius can cause the compound to break down rapidly. Contamination with organic materials, acids, or metals can lower this threshold significantly.
When ammonium nitrate decomposes explosively, it releases nitrogen gas, oxygen, and water vapor at extremely high temperatures and pressures. The reaction is self-sustaining once initiated, with the heat from decomposition triggering further breakdown in a chain reaction.
The addition of fuel oil to ammonium nitrate creates an ideal explosive mixture because the fuel provides combustible material while the ammonium nitrate supplies abundant oxygen. This combination is particularly attractive to terrorists because both components are readily available and legal to purchase for agricultural and industrial purposes.
Storage and Safety Regulations
India's PESO has established strict regulations for ammonium nitrate handling. The compound must be stored in cool, dry, well-ventilated areas away from heat sources and incompatible materials. Storage facilities require proper security measures to prevent theft or misuse.
According to PESO guidelines, ammonium nitrate should never be stored near combustible materials, and quantities above certain thresholds require special licensing and monitoring. The rules mandate regular inspections and proper record-keeping of all ammonium nitrate transactions.
Despite these regulations, the Delhi blast demonstrates the persistent challenge of preventing agricultural fertilizers from being diverted for malicious purposes. The premature detonation in this case – triggered by the suspect's haste due to ongoing police raids – likely prevented an even larger catastrophe at what may have been a more populated target location.
The Red Fort car explosion was preceded by a 20-day-long probe in Jammu and Kashmir linked to two terror outfits including Jaish-e-Mohammad (JeM). At least 20 others continue to be questioned in the Valley as investigators work to dismantle the entire terror network.
The investigation, handed to the National Investigation Agency (NIA), identified a doctor from Pulwama as the likely vehicle occupant, with eight arrests made in connection to a terror module linked to Pakistan-based Jaish-e-Mohammad (JeM).