Balloons are probably one of the toys most popular with children but the recent blast from a balloon vendor’s gas cylinder at the capital’s Mirpur has once again raised the question: how safe are gas balloons?
The explosion at Rupnagar on Wednesday (Oct 31) has killed seven children and injured more than 14 pedestrians. Amongst them, seven children are still in critical condition at the Dhaka Medical College Burn Unit.
Throughout the world, balloons are filled with the non-reactive helium gas, but in Bangladesh, vendors use hydrogen, a highly combustible gas when it comes in contact with oxygen.
Although the vendors use small cylinders in hopes of more profit, they are unaware that they are carrying a death trap that experts compare to a bomb.
Experts say that that helium is the preferred gas for balloons in the whole world but Bangladeshi vendors go for hydrogen as it’s much cheaper.
Rupnagar police OC Abul Kalam Azad said that they arrested the balloon vendor Abu Syed immediately after the explosion. He was undergoing treatment at Shaheed Suhrawardy Medical College and Hospital.
According to OC Azad during primary interrogation, Syed admitted to producing the gas himself from chemicals obtained from Old Dhaka’s Chawkbazar. “He started the balloon trade 15-20 days ago.”
Explosions from gas balloons are not new. Last year 10 people were burnt following an explosion in a bus on the way to a Chhatra League rally.
Those injured said that everyone on the bus had a balloon which went off when it came in contact with something flammable or hot.
Experts are of the view that a cigarette is enough to set off a hydrogen gas balloon and helium being non-reactive does not pose the same risk.
Former Bangladesh University of Engineering and Technology (BUET) professor and BRAC University Pro Vice-Chancellor Mohammad Tamim says that hydrogen is preferred to helium as its much cheaper.
“It’s always risky if hydrogen is used in balloons,” he said.
Meanwhile, Chief Inspector of Explosives Shamsul Alam told Bangla Tribune that what the balloon vendors use are not actually cylinders but gas-producing reactors which are completely banned by the Department of Explosives.
“Gas cylinders have been modified so that the hydrogen gas is produced inside,” he said.
He added that hydrogen is produced while the balloon is being filled through the reaction of caustic soda and aluminium powder in the cylinder.
“When there aren’t any customers, they [vendors] close the knob. But hydrogen gas keeps on being produced, increasing pressure inside the cylinders.”
Alam said that the increased pressure keep eroding the insides of the cylinders which at one point becomes weak and explode.
“The police should detain anyone using with these cylinders but they don’t. We have written to them countless times regarding this,” he said.
A top police official said that the concerned division was working to see whether the police can stop these businesses.