At least two skin-whitening products sold in Hong Kong contain dangerous levels of mercury. The two products contain mercury levels that are 24,000 and 550 times the recommended dosage, according to tests conducted by the Customs and Excise Department. A department spokesman said officers were still investigating the suppliers 'with a view to prosecuting five parties for importing and supplying offences'. But Chinese University's Professor Chris Lam Wai-kei and his research partner, Prince of Wales Hospital doctor Michael Chan Ho-ming, found eight brands manufactured on the mainland or Taiwan exceeded the United States Food and Drug Administration safety limits. One of the creams contains 65,000 times the recommended guideline of one part per million of mercury. Professor Lam said the discrepancy between his results and those of the Customs Department were due to the fact they probably had tested different products because he had not released the brand names in question. The Customs Department and Professor Lam refused to name the brands containing mercury. The toxin can damage the bones and nervous tissue. It even causes kidney failure, psychiatric problems and cerebral palsy. Mercury compounds in the cream can also deposit in the skin and produce a dark or rusty-grey colour. Products that use mercury work by inhibiting the production of melanin. Professor Lam's tests on 38 brands of skin-whitening, bleaching and anti-freckle creams were carried out late last year, but the results have only been recently released. He said one mainland supplier approached about the toxic content replied: 'What is wrong with a little mercury in the cream, as long as it can make ladies beautiful?' Professor Lam and the Consumer Council have called on the Government to strengthen regulations on product labelling and purity requirements for cosmetics, herbal medicines and other consumer products that may contain toxic ingredients or contaminants. 'At present our Customs service does not seem to require compulsory product labelling or a certificate from a local or overseas laboratory to certify purity,' Professor Lam said. Manufacturers, suppliers and importers are responsible for ensuring their cosmetic products are safe. Consumer Council head of research and surveys Connie Lau Yin-hing said it had conducted a similar test in 1994 on 21 creams that found traces of mercury in six samples. The toxin was presumed to be a contaminant so prosecutions could not be launched. Ms Lau said the council received almost 70 complaints a year about cosmetics but did not keep figures relating to skin-whitening problems.