From fertiliser to fireball: Chemistry that turns everyday compounds into explosives

New Delhi, Nov 11 (PTI) The investigation into Monday evening's blast near Red Fort that killed 12 people has turned the spotlight on the massive seizure of 2,900 kg of explosive materials in Faridabad -- a cache that, according to experts, could be a highly volatile mix of oxidisers, fuels and sensitisers, the same chemical principles that make up most industrial explosives.

Police are suspecting that ammonium nitrate, potassium nitrate and sulphur were among the recovered substances from Faridabad, while invoking terror-related charges under the Unlawful Activities (Prevention) Act.

The Delhi Police FIR describes the incident as a "bomb blast", while forensic experts are now analysing whether the materials seized from Faridabad match the chemical signature of the Red Fort explosion.

“All explosive compounds can broadly be classified into three components – fuel, oxidiser and sensitiser,” Manish Jain, professor in the department of applied chemistry at the Delhi Technological University, told PTI.

"Ammonium nitrate and potassium nitrate act as oxidisers, supplying oxygen for combustion, while elements such as sulphur and carbon serve as fuels.

"When a sensitiser is added, the mixture becomes easier to initiate and can rapidly transition from burning to detonating,” he said.

Ammonium nitrate (AN) is one of the most common oxidisers used in fertilisers and in controlled industrial explosives such as ANFO (ammonium nitrate-fuel oil).

However, when mixed improperly or with additional fuels, it can become dangerously unstable.

“Adding ammonium nitrate to potassium nitrate and sulphur produces a highly-volatile and sensitive mixture – much more prone to detonation than black powder itself,” Jain said.

Anand Prakash, assistant professor in the department of chemistry, Rajdhani College, University of Delhi, called the recovery “deeply concerning”.

“Ammonium nitrate is a powerful oxidiser, potassium nitrate supplies oxygen to sustain combustion, and sulphur lowers ignition temperature and helps the reaction spread. Together, these dramatically raise the sensitivity and destructive potential of a mixture,” Prakash said.

Officials said that among the seized materials, around 360 kg was inflammable and suspected to be ammonium nitrate.

Investigators suspect that the cache is linked to a white-collar terror module involving the Jaish-e-Mohammed and Ansar Ghazwat-ul-Hind networks spanning Kashmir, Haryana and Uttar Pradesh.

The experts cautioned that the chemistry of such mixtures is deceptively simple – and that everyday industrial and agricultural substances can become deadly with minor changes in formulation.

“The danger lies not just in the chemicals but in how they’re combined, stored and triggered,” Prakash said.

As forensic teams compare the blast residues from the Red Fort site with samples from the Faridabad haul, the focus now shifts from the immediate terror link to the chemistry of destruction – understanding how a few kilograms of common compounds can, under the wrong hands, turn into a catastrophic explosive. PTI MHS ARI ARI