Woman who use fake tan could be at an increased risk of fertility problems and having babies with birth defects, experts have warned.
Researchers have expressed fears that tanning products - seen as a safe alternative to sunbeds - could damage DNA.
Dr Lynn Goldman, dean of the School of Public Health and Health Services at George Washington University, in Washington DC, said: "What we're concerned about is not so much that reaction which creates tanning but reactions that may occur deeper down with living cells that might then change DNA, causing a mutation, and what the possible impacts of that might be."
However, cosmetics firms have argued that fake tan is safe.
Dr Chris Flower, director general of the Cosmetics, Toiletry and Perfumery Association said: "There are stringent EU laws covering the manufacture if cosmetic products."