• Wed
  • Oct 1, 2014
  • Updated: 12:51pm

Warning on danger peroxide levels in tooth whiteners

PUBLISHED : Sunday, 15 September, 1996, 12:00am
UPDATED : Sunday, 15 September, 1996, 12:00am

SOME teeth whiteners could wipe the smile off your face - they contain more than 100 times the recommended level of hydrogen peroxide.


The Consumer Council yesterday warned people to use only tooth whiteners prescribed by dentists.


It said using whiteners with a high hydrogen peroxide content could cause inflammation, swelling and bleeding of gums. If the chemical was accidentally swallowed it could lead to vomiting and internal bleeding.


The council's latest tests found seven samples of tooth whiteners, all from the United States and priced from $39.90 to $299, contained 2.6 per cent to 10.4 per cent of hydrogen peroxide.


Two samples from Natural White Tooth Enamel Whitening System No 302W and Professional Bleaching System No 304W, had 9.9 per cent and 10.4 per cent.


The levels were in excess of the 0.1 per cent limit under the European Union's requirement by 26 to 104 times.


Dr Lo Chi-kin, chairman of the council's publicity and community relations committee, said consumers must be careful in using these products as at present there are no laws to regulate them.


'Excessive hydrogen peroxide may pose potential health risks to the user,' he said.


'Accidental ingestion of excessive hydrogen peroxide may result in a sudden generation of large amount of oxygen gas, causing the stomach to expand rapidly that may induce symptoms of nausea, vomiting and internal bleeding.' The council said authorities in the US were evaluating whether tooth whiteners should be regulated as drugs or as cosmetics.


Public concern was raised over the use of hydrogen peroxide after Church of Zion leaders and followers claimed that drinking the chemical could cure cancer and AIDS. The Health Department has warned the chemical is only for external use. The council also found some sandwiches sold in fast-food outlets and bakeries contained bacteria exceeding the acceptable level.


Only five of the 20 samples of tuna, chicken and ham and egg sandwiches sold at 11 outlets were hygienic enough.


A chicken sandwich had an E coli count of 11,000 per gram, exceeding the acceptable level of 100 by 1,100 times.


The Health Department said it had stepped up inspections. It had tested 290 sandwiches since 1995 and more than 80 of them were satisfactory or acceptable. Two poisoning cases involving contaminated sandwiches had been reported.


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