Slaked lime production faces extinction threat

Producers of slaked lime made from oyster shells, popularly known as kali chun, are leaving their ancestral profession for low demand for their product and high cost of production materials.

Over 200 makers who live in Dinajpur’s Sadar upazila had been involved in the hereditary profession of making slaked lime from oysters for centuries, and their contribution to the craft has led to their village’s name as Chuniapara, roughly translated as the village of lime makers.

However, they said that oyster scarcity in the local market, competition from industrially produced calcium hydroxide, and low demand for betel leaves and nuts which are eaten with slaked lime are the reasons behind the losses they face in their business.

The producers told The Business Post that currently, they have to spend Tk 500 to produce a maund of slaked lime, which sells for only Tk 600 to Tk 700 in the local market. Whereas they used to buy two maunds of their sole raw material, oysters, for Tk 250 a year ago, they are now buying the same volume for Tk 500, which is double the amount they used to pay.

Malini Roy, who works alongside her husband and other family members, said they have to buy oysters from shell collectors. In the past, these freshwater oysters were available in abundance in rivers, canals and other water bodies, which has become scarce now.

She said that one maund of shells costing Tk 300 is needed to produce one mound of slaked lime. With fuel and labour to fan the kiln, around Tk 500 to Tk 600 is spent for making one maund of slaked lime based on their quality and kind.

“After we collect the oysters, we boil them to help open the shells and extract the flesh. The shells are then piled for a couple of days to dry off, then burnt in an earthen kiln. Water is added to the ashes of the burnt shell to make slaked lime, Santi Rani, another slaked lime maker of the area, explained.

Besides the cost of shells, the production method needs firewood, jute stick and straw required to burn the shells, which increases the production cost, even more, she said.

“There were around 1000 slaked lime producers in Chuniapara. But as the production cost gradually rose and demand nosedived, they used to leave the profession. Now we have around 100 active slaked lime producers in the locality, and the rest 100 seasonal producers,” said Moksed Ali Rana, an influential person of the locality.

“To save the age-old profession and help the producers, the government needs to introduce incentive packages so that the producers can use improved technology for the burning process that could bring their cost down. It can also help them compete with the industrially produced slaked lime,” said Habibul Islam, executive member of the Bangladesh Economic Association.

He further said that slaked lime production from oyster shells could be considered as a small cottage industry, through which the producers would be able to collect loans with easy conditions, which will eventually save the industry from extinction.

Reduced water flow from the encroachment of rivers and canals, unplanned use of pesticides, and waste disposal in water bodies has created an adverse environment for oyster breeding, he added.