Pharmacists have warned parents about the possible deadly effects of an ingredient in a popular remedy for mouth ulcers after the Department of Health declined to provide guidance. Some 25 products sold over the counter in Hong Kong contain choline salicylate salts, including Bonjela. The ingredient can increase the risk of Reye's syndrome - a potentially deadly brain and liver disease - in children. The Society of Hospital Pharmacists yesterday issued a formal request for government guidance. The warning about the dangers of products containing the salts was issued by a medical watchdog in Britain on Thursday. There have been no confirmed cases of the disease being linked to the products. 'This is very serious because the Department of Health should be informing people about the problem,' said William Chui Chun-ming, the society's education director. 'We believe these products should be repackaged with a warning. We also recommend that parents treating mouth ulcers use salty water until further guidance is given by the government.' Products such as Bonjela Teething Gel are safe because they do not contain the salts. The Department of Health said the product registration committee would discuss what measures to take on Monday. Reckitt Benckiser, the company that makes Bonjela, said it was awaiting direction from the government before proceeding with packaging changes. A spokesman for Prowin Labs, producer of 15 out of the 25 named products, said: 'We will take immediate precautions to stop the use of these products by children.' The Practising Pharmacists Association advised pharmacists to stop recommending the products to people under 16.