More than a third of all furniture products and 14 percent of all leather goods manufactured here contain unsafe levels of formaldehyde, a chemical that can cause leukemia, a study by the city's quality and technology supervision bureau has found.

Forty-five of 132 batches of furniture and 11 of 80 batches of leather goods were not up to standard because of their high formaldehyde content, a press release issued by the bureau on Monday said.

The formaldehyde emissions from a particular type of bedstead were 3.7 times the national standard, it said.

Formaldehyde irritates the lungs and eyes, and can trigger attacks of asthma and even cause leukemia if a person is exposed to it for long periods, Jiang Chaoqiang, a doctor with the Guangzhou No 12 Hospital, said yesterday.

Last month in Shenzhen, an 11-year-old girl required hospital treatment after being poisoned by formaldehyde fumes coming from her bedroom furniture.

The toxic chemical is used to make plywood for furniture.

Dai Kunfeng, director of the bureau's quality division, said yesterday: "Cheap plywood is to blame for most of the substandard products.

"The furniture we sampled was for the domestic market."

Most of the substandard products came from small firms, whose owners buy cheap plywood to reduce costs, Dai said.

The quality and technology supervision bureau has asked manufacturers to reduce the amount of formaldehyde they use and called on them to stop selling the potentially harmful products and recall those they have already sold, he said.