Officers from Northamptonshire Trading Standards seized the kits, which have more than 100 times the legal amount of the chemical, from a firm in the town.
The authority has warned anyone who may have bought one of the kits not to use them, claimi
ng high levels of hydrogen peroxide can act as a "weak cancer promoter", stimulating the growth or multiplication of cancer cells.
Northamptonshire County Council's cabinet member for community safety, Coucillor Liz Tavener (Con, Duston) said: "Tooth whiteners have increased in popularity over the past few years and people may have chosen one of these kits believing them to be safe to use.
"But anyone getting tooth whitening done should ask whether the product they are using contains hydrogen peroxide over 0.1 per cent.
"Anyone who thinks they may have bought these items should not use them and contact trading standards for advice."
The kits were being imported to the UK by the Northampton-based company then sold over the internet as well as to dentists and other businesses.
Trading Standards has told all businesses found selling the product to stop and warned them any further sales will lead to enforcement action.
Dentists have also warned people who may have bought the teeth whitening kits over the internet not to use them.
Dr Atif Qureshi from the British Academy of Cosmetic Dentistry, said: "If anyone has bought a kit containing 10 per cent levels of hydrogen peroxide, that is extremely high.
"People could very easily end up burning their throats with that.
"Shops can't legally sell anything above 0.1 per cent so they're right to have seized these kits.
"If people are using them on themselves the worry is how much of it could go down their throats."
However, Dr Qureshi questioned the link between teeth whitening and cancer, adding: "I think concerns about cancer are pretty baseless.
"Hydrogen peroxide does have a risk, just like any other chemical. But quite frankly most people contract mouth cancer by drinking spirits."
The county council has not named the company which was supplying the teeth whitening kits, but anyone who is concerned about any treatment they have had can call Trading Standards on 08454 040506.
wayne.bontoft@northantsnews.co.ukThe full article contains 406 words and appears in Northampton Chron & Echo newspaper.
