The industry dates back nearly 80 years, taking root in this quiet village of Kimbulapitya, 45 kilometers away from Colombo.
While work remains seasonal, peaking during Christmas and the April New Year season, production techniques have not kept pace with modern times, leaving room for health and pollution hazards and mishaps that can turn fatal.
Gunpowder wafts in the cool air, while young men with their skin stained with silver explosives, mix chlorates, phosphorous and sulphur to make popular seasonal favourites like firecrackers, sparklers and skyrockets.
Workers, many under-age, handle explosive chemicals with little or no safety equipment, while children run about the work place and also help in repetitive work like cutting paper, pasting gum or filling sand into fireworks.
"The adults do the risky work, while children help out to make the gum, cut paper and roll it. It's the way of life here," says 32-year old P Sumanasiri, who also works part-time as an electrician.
Sumanasiri, admits he does not have a license to make fireworks, but has been plying the trade nearly all his life having picked up the craft from his father.
Over 76 factories are licensed to work in Kimbulapitiya, but few dozens ply their trade illegally, with fireworks made in virtually in every home in this idyllic village.
Kimbulapitiya, incidentally, has the highest concentration of fireworks industry, (with Kandy District a distant second), giving employment to the entire village, distant relatives of family members and outside help.
"It's the mainstay of people in this area, though it's dangerous because people mishandle chemicals or don't take proper precautions," explains 85-year old B Albert, while busying himself rolling purple coloured firecrackers.
Albert, who has been in the business for over 55-years, says frequent accidents are scaring workers away from this industry, though people limit the use of potassium chloride, a highly explosive ingredient.
"So far, six people have died this year in two separate incidents, but there are daily injuries sometimes near fatal, which very often go unreported," says 27-year old Saman Nilantha, who is employed in a makeshift firework unit.
Nilantha, like dozens of others, migrate to Kimbulapitiya each year to work for around eight months, before returning to their villages.
While smoking is banned where fireworks are made, safety gear is often the bare minimum, limited to the occasional handkerchief to cover noses and mouths.
"Smoking on the sly on the work site is one of the main causes for accidents in this area," says Nilantha.
The lack of laboratory facilities, means workers test the strength of explosives by themselves, leaving room for other forms of accidents.
"We light the cracker to test the chemical strength, packaging around it. It's the same with other special jobs we undertake," says 26-year old Neville Fernando, who is in the business for the fourth year.
"There is no choice but to learn by mistake," Sumanasiri says showing us burnt marks and scars on his face and hands.
Locals report that workers suffer from chronic bronchitis, burns, skin disorders, eye and infections.
"But everyone in this village makes fireworks, it's risky but it's our way of life," says Sumanasiri.
Skyhigh raw material prices have also blown a hole to firework makers here.
"It costs over Rs. 50,000 each month now to buy chemicals, but our selling prices have not changed for two-years," complains A Malkanthi, while helping her husband G S Nishantha dip sparklers into gunpowder.
Locals also defend the use of children to work in this trade, saying the kids merely 'help parents' after school hours or during peak seasons like April and December.
"She doesn't mind helping us," gestures Malkanthi to her 7-year old daughter who fills sand into the small firecracker tube.
The fireworks industry has often featured prominently as one of the key employers of child labour, according to the International Labour Organisation.
In Sri Lanka children are also used as beggars, child soldiers, in domestic work and as commercial sex workers, the ILO said in a report.
Sri Lanka is currently partnering along with five other countries to study children working these sectors.
"The report, which comes out in a few weeks, also looks into the demand side of the fireworks industry," says Shyama Salgado, National Programme Manager of ILO's International Programme on the Elimination of Child Labour.
-Mel Gunasekera: firstname.lastname@example.org