Firecrackers made of potassium chlorate mix are highly sensitive to friction.
In common parlance, the concluding segment of a competitive public fireworks display is known as “Asan’s choice”.

 It marks the zenith of the demonstration when leaders of competing teams try to outdo each other by putting on view the most thunderous and dazzling show for judges and spectators.

 The blast that killed over 100 people and injured 400 more in Paravur on Sunday had occurred at the start of the no-holds-barred final segment of the ill-fated fireworks competition at the local Puttingal temple, according to police.

 The premature bulk detonation of rockets and bangers stocked for controlled use in the final session had caused the blast that was felt intensely over a radius of 1.5 km.

 The competing firework display teams, like many others in their trade, had possibly used potassium chlorate, a banned explosive, to make their final set of crackers louder and brighter than that of their rivals. They had possibly sourced the chemical illegally from matchstick factories, investigators said.

 “Huge prize money and reputations were at stake. The final set of crackers that caused the blast was more powerful than those exploded earlier. Forensic experts suspect that aluminium powder and sulphur were also used with potassium chlorate to make them potent.

 One police theory was that the brusque loading of the firing tubes at the end stage of the competition could have altered their orientation, causing flaming debris from the rockets to fall on the stocked firecrackers and spectators.

 Negligent handling in the storage area could also have caused the blast. Firecrackers made of potassium chlorate mix are highly sensitive to friction, pressure and temperature, a reason why the chemical was banned in firecracker production in the 1990s.
‘The final set of crackers that caused the blast was more powerful than those exploded earlier’