Why investigators are tracking ammonium nitrate link between Delhi blast and Faridabad haul, Pg4.

Key Highlights:

• Investigators are analyzing evidence from the Red Fort blast to confirm if ammonium nitrate was used.
• The analysis aims to link the Delhi blast with the Faridabad terror module, where 358 kg of ammonium nitrate was seized.
• Ammonium nitrate has been widely used in terror blasts in India, especially before 2012.
• Access to ammonium nitrate is regulated, requiring permission from a District Magistrate for up to 30 metric tonnes or PESO approval for larger quantities.
• SETT (System for Explosive Tracking and Tracing) monitors licensed transactions of explosives.

Detailed Insights:

• Before 2012, ammonium nitrate was a key component in almost every major terror attack in India; today, terror groups still use it in IEDs (Improvised Explosive Devices).
• A blast with 350 kg of ammonium nitrate could severely damage over a hundred vehicles in the vicinity.
• Even after a blast site is washed, traces of ammonium nitrate can be detected through highly sensitive chromatographic tests on residues clinging to dust, clothing, or surfaces.
• ANFO (Ammonium Nitrate Fuel Oil), typically composed of 94% ammonium nitrate and 6% fuel oil, requires a detonator to initiate the blast.
• Elevated levels of nitrate ions (NO₃⁻) in the environment can indicate the prior presence of ammonium nitrate, as nitrogen oxides from the explosion dissolve in water to form nitric acid.
• Establishing a direct link between ammonium nitrate found in a suspect's house and the blast is challenging, often relying on circumstantial evidence due to the availability of explosives in areas with mining activities.
• Confined blasts involving ammonium nitrate can produce detectable brownish nitrogen oxides like nitric oxide (NO) and nitrogen dioxide (NO₂) immediately after the event.

Scientific/Technical Concepts Involved:

• Ammonium Nitrate: A chemical compound used in fertilizers and explosives, regulated due to its potential for misuse.
• ANFO (Ammonium Nitrate Fuel Oil): A widely used explosive mixture of ammonium nitrate and fuel oil, requiring a detonator for ignition.
• Chromatography: A laboratory technique used to separate and analyze complex mixtures, enabling the detection of minute traces of substances.
• Nitrogen Oxides (NOx): Gases produced during ammonium nitrate explosions, which can be detected to identify the use of such explosives.