A local rubber manufacturer plans to set up a plant in Shanghai this year to recycle used tires, which pose a potential threat to the environment if not properly treated.

While environment experts say the plant will reduce pollution, the firm is worried it won't have a large enough supply to feed its appetite.

"We have talked to a few big recycling stations about their support, but the supply could still be a problem," said Hu Jiaqing, vice general manager of Shanghai Honglei Complete Equipment of Fine Rubber Powder Co.

The plant, which is scheduled to open in August in suburban Qingpu District, will be capable of recycling 50,000 tons of used tires each year, accounting for about 90 percent of the city's used tires.

The tires will be turned into fine rubber powder to make new rubber products, according to Wu.

Currently, the city produces about 6 million waste tires each year. But only about 10 percent of them are ever recycled, according to the tire division of the China Rubber Industry Association.

Many used tires are simply left in the open air, mostly in the suburbs. Some are collected by migrant workers and then transported to other provinces, while others simply pile up in warehouses.

"We have never collected tires as they don't sell well, although our staff can often encounter the old tires in suburbs during their work," said Chen Lishan, who runs a waste recycling company in the city.

The waste tires piled up in the open air don't just occupy land, they can also pollute the environment as they will break down and produce some poisonous materials after they are exposed to rainfall and sunlight for a long time, environmental experts say. "They pose a potential threat to the environment and they should be properly treated before they cause any damage," said Su Guodong, pollution control division chief with the Shanghai Environmental Protection Bureau.

Industry insiders said not recycling waste tires is a waste of resources as rubber prices have been rising at international markets for the past several years.

"They can be turned into rubber powder, which will be much cheaper than making new rubber. Some tires can simply be renewed to be used again," said Tian, the tire division vice secretary general.