In a small warehouse in Cambodia's capital, a group of workers sit and spin waste plastic bottles into strips, turning them into bristles for brooms, of which they churn out 500 each day.

For the past 11 months they have transformed around 40 tonnes of discarded plastic bottles, about 5,000 bottles per day, by "upcycling" them into brooms they say are more robust than regular brushes.

Those sell for 10,000 riel ($2.50) and 15,000 riel ($3.75) each.

Plastic strips from the empty bottles are collected into a bundle on a machine, before being softened in hot water and sliced evenly to be sewn with metal wires into the ends of a bamboo stick.

Cambodian entrepreneur Has Kea, 41, wants to reduce plastic pollution in his community, in a city that produces up to 38,000 tonnes of all types of waste each day, according to its environmental department.About a fifth of that is single-use plastic that ends up in landfills and waterways.

"This broom is quite solid, not easy to break," said Suon Kosal, a 26-year-old Buddhist monk whose temple bought 80 of the brooms last month.

Kea buys empty plastic bottles from trash collectors and garbage depots. With the seemingly endless supply, he is confident about the longevity of his business.

He is also open to competitors stepping in to the market.

"This also help reduce pollution to the environment and encourages people to collect plastic bottles to sell to us at a higher price, which in turn, could earn them a better living," he said.