Experts are warning a chemical used in sun creams and moisturisers can trigger allergic reactions.

The chemical, methyldibromo glutaronile, is used in a range of cosmetic products, but it is these 'leave-on' products which are causing dermatologists concern because exposure to the product is greater.

The European Union licenses the product for use in such products, but its advisors are now calling for restrictions on its use.

There are concerns it could cause reactions such as swelling, itching and painful dermatitis.

Dr Ian White, chairman of the EU's Scientific Committee on Cosmetic and Non-Food Products and consultant dermatologist at St Thomas's Hospital, London, said the chemical had been used for many years, but it has become more widely used recently.

The industry was warned a year ago about this but did nothing

Dr Ian White,

The committee wants investigation into the safe dosage levels for the chemical.

Brands including some used by Boots and Marks and Spencers include the chemical.

Data from across the EU has shown a 400% rise in the number of people with eczema who had an allergy to the chemical, rising from 0.7% in 1991 to 3.5% in 2000

Concerns

Dr White told BBC News Online: "We heard the alarm bells ringing, so we warned about the situation."

He said the committee felt exposure to the chemical should be reduced to a safe level.

Dr White said the cosmetics industry has already been made aware about doctors' concerns.

"The industry was warned a year ago about this but did nothing."

It is up to individual EU states to act on the committee's recommendations.

In addition to its use in cosmetic products, the chemical is used in detergents, though a difference in labelling rules means it is not always identified.

Safety

A spokeswoman for Boots told BBC News Online: "The safety of our customers is of paramount importance and we continuously review the ingredients in all our products.

"Methyldibromo glutaronitrile (MDBGN) is currently licensed for use in cosmetics within the European Union. It is used by Boots and widely in the toiletries industry.

"The Boots products that do contain MDBGN, do so at lower than permitted levels."

She added: "We will continue to review and monitor the situation, working closely with the European Commission.

A spokesman for Marks and Spencer told a national newspaper: "Materials can be withdrawn if new research shows they are liable to cause damage to human health."