It is hard to find a birthday party without a few floating balloons.
But in order to get the balloons to defy gravity, one needs a gas that’s lighter than air, namely hydrogen or helium.
Since hydrogen is the cheaper of the two gases, most vendors in the country use it to inflate balloons.
However, the method in which most of the vendors produce the inflammable gas has proven to be risky on many occasions.
A cylinder used for inflating balloons exploded last week in the capital’s Rupnagar killing seven children and injuring 20 others. Six of the injured children are being treated at Dhaka Medical College Hospital.
Besides, a hydrogen balloon can cause mishaps if it catches fire.
“There is neither any act nor any regulation regarding the use of hydrogen in balloons,” Samsul Alam, chief inspector of the Department of Explosives, told The Daily Star.
Officials and balloon sellers said that the vendors collect old and discarded LPG and CNG cylinders and, with some modifications, use them for producing hydrogen.
They modify the cylinders to be able to put aluminium powder, sodium hydroxide and water inside, and then seal it, said Samsul.
The mixture produces hydrogen which is trapped inside the cylinder.
When they inflate the balloon, they use a valve on the cylinder to let gas out.
But they cannot control the production of hydrogen inside the cylinder, he said. As hydrogen continues to be produced, the cylinder gets hot due to the pressure and at one point, the cylinder explodes, he said.
Experts said hydrogen is an unstable and inflammable gas and there is great danger associated with hydrogen balloons.
Alam said public awareness and police action could change the situation.
“Hydrogen is not the problem; the problem is the way the balloons are inflated,” he said.
It is not possible to formulate law for everything, he said. “We have to be aware and if we see vendors use such things, we should inform police,” he said.
Alam also said this method of inflating balloons is not safe. “We have brought the issue to the attention of the administration several times. We published advertisements in newspapers, making people aware.”
Experts, however, called on the government to ban hydrogen balloons.
“Helium does not explode. Even if it comes into contact with fire, it just pops. But hydrogen is highly inflammable,” Mohidus Samad Khan, associate professor of the Department of Chemical Engineering of BUET, said.
“There are many incidents where people got injured in other parts of the world due to hydrogen-filled balloons,” he said.
It should be brought under a legal frame, Brig Gen Sazzad Hussain, director general of Bangladesh Fire Service and Civil Defence, told The Daily Star.
On January 25, a balloon vendor was killed and two others were injured when their cylinder exploded on Dhaka Shikkha Board Laboratory School and College campus in the capital’s Mirpur.
Two balloon vendors died and two others were wounded in a cylinder explosion in Jatrabari on February 5, 2017.