A new investigation has found that illegal teeth whitening kits containing more than 500 times the legal limit of dental bleach can cause permanent scarring of the gums, destroy tooth enamel, damage nerves, and cause chemical burns to the lining of the mouth.

In spite of the damaging impact of the bleach, they are being sold on social media and distributed in car parks In the UK, teeth whitening treatments that use more than 0.1 per cent hydrogen peroxide— a bleaching agent used to get rid of stains on teeth—can only be carried out by a dentist or other professional registered with the General Dental Council (GDC).

The regulations also state that any bleaching gels used for teeth whitening treatments cannot contain more than six per cent hydrogen peroxide.

However, the BBC investigations revealed that some illegal teeth whitening gels being sold on social media have in excess of 500 times the legal limit. Worryingly, they also found it was easy to obtain a fraudulent teeth whitening qualification, which could put people unknowingly at risk.

One of their reporters obtained a fake qualification and ‘extreme bleach’ from an online seller and was told to ‘practice on friends and family’.

Experts are warning people to be vigilant in checking that their treatments are being done by qualified professionals to avoid being left with painful burnt gums and in some extreme cases, tooth loss.