Richard Bence, who advocates the use of organic beauty products, said people should question the products they put on their skin, The Telegraph newspaper said Thursday.

"We have no idea what these chemicals do when they are mixed together; the effect could be much greater than the sum of the individual parts," he said.

The Cosmetic, Toiletry and Perfumery Association said cosmetic products are covered by European Union rules requiring them to be safe.

"The cocktail effect is an urban myth," a spokesman told the newspaper. "We do know how different chemicals react individually and can predict how they interact with each other and this is taken into account when the safety of products is assessed."