Popular imported water purifiers produced water containing excessive levels of arsenic and colonies of bacteria, the Ministry of Health has said.
Eleven products of eight brands, including Panasonic, Mitsubishi and 3M products, were found to produce excess levels of arsenic. Most of the products were produced in the past two years, ministry officials said.
Medical experts said absorbing arsenic over a long period may increase the risk of cancers, especially skin, bladder and lung cancer.
Bacteria was also discovered in water treated by some of the purifiers.
The products will be removed from shelves. Details are listed on the ministry's website but only in Chinese.
However, Panasonic China said that no excess arsenic was found from the products during tests conducted by the company and a third party. Panasonic has submitted an application to the health ministry for a second test.
"No arsenic was used in the production of the water purifier," Panasonic spokeswoman Xu Ying said. Consumers can contact local after-sales departments to return products for a refund, she said.
3M China asked consumers to exchange filters for new ones. 3M attributed the problems to improper packaging instead of defects in the products themselves.
Meanwhile, Philips is recalling 1.75 million hair driers on the Chinese mainland, as they may catch fire in extreme conditions due to problems with switches.