Some teeth-whitening kits have been taken down from online retailers after they were found to contain illegally high levels of hydrogen peroxide.
More than 20 products for home use were found to exceed the legal limit of the chemical, which can burn gums and cause dental damage, as part of an investigation carried out by consumer group Which?.
One of the 36 kits tested was found to contain 300 times too much of the active ingredient.
Teeth-whitening products for use at home are allowed to contain up to 0.1 per cent hydrogen peroxide, while the legal limit for application by professional dentists is 6 per cent.
Which? said the unsafe products have now been removed from online marketplaces after the consumer group flagged the results of its investigation to the relevant companies.
Sue Davies, head of consumer protection policy, said: “It’s worrying that our tests have revealed so many of these products sold on online marketplaces – and often hyped on social media – are breaking legal limits for hydrogen peroxide and putting the health of users at risk.
“It’s clear that self-regulation is not working, leaving people exposed to a flood of unsafe products online.”
The worst offender found by Which? was a bleaching gel kit containing 30.7 per cent hydrogen peroxide on AliExpress.
AliExpress told the group: “We take product safety very seriously and after being notified by Which? of its findings, we took prompt action and removed the third-party product listings identified to be in violation of our listing policy.”
Dr Paul Woodhouse from the British Dental Association said: “Hydrogen peroxide is a seriously strong chemical and not to be messed with.
“Dentists are trained in its usage and they also know what whitening products are effective to use and safe for teeth and gums.
“If you destroy gum tissue, you are never going to get it back and you lose your teeth. If it penetrates the surface of your tooth, which is likely, it’s probably going to lead to the death of that tooth.”
