What exploded in the AZF fertilizer factory incident in France?

• A. MCMT
• B. HCL
• C. MIC
• D. Ammonium nitrate

Answer: (D)

Ammonium nitrate is an oxidizer used in many fertilizers, and when it is stored in large quantities and exposed to heat or a fire, it can detonate rather than merely burn. In the AZF fertilizer plant incident near Toulouse in 2001, a fire spread to a storage area containing a large amount of ammonium nitrate, leading to a massive explosion that caused extensive damage and casualties. This situation underscores the well-known hazard of concentrated ammonium nitrate in fertilizer operations.

The other substances listed are not the material involved in this event. Methyl chloroformate-type compounds, hydrochloric acid, and methyl isocyanate are separate chemicals used in different contexts and do not explain the catastrophic blast that occurred at AZF.