A sunscreen filter frequently found in sunscreen and anti-aging cream is degrading into a hormone-disrupting compound suspected of being carcinogenic, according to researchers who call for banning it from personal care products.
The ingredient, octocrylene, found in many cosmetics (moisturizing creams, self-tanning creams, shampoos, etc.), is transformed into benzophenone, which accumulates rapidly with the aging of the product, shows a Franco-American team. She analysed about fifteen sunscreens and anti-aging creams purchased in France and the United States.
Their work is published on Monday in a specialized journal of the American Society of Chemistry, Chemical Research in Toxicology.
Octocrylene is accused of being harmful to marine life, especially for corals. 'Some manufacturers have removed it from their sunscreens for environmental reasons,' says Philippe Lebaron, a biologist at the Biodiversity and Microbial Biotechnology Laboratory at the Banyuls-sur-Mer Observatory (Sorbonne University/CNRS, France). co-author of the study.
Territories with coral reefs, such as the US Virgin Islands or the Republic of the Marshall Islands, have banned octocrylene in sun protection products, the researchers say.
Benzophenone is classified as 'possibly carcinogenic to humans (Group 2B)' by the WHO International Agency for Research on Cancer (IARC). And according to this health agency, there is sufficient evidence in laboratory animals of the risk of benzophenone-induced cancer.
In animals, exposure to benzophenone induces liver cancer and lymphoma, note researchers who also point to dermatological problems.
The products purchased have undergone an accelerated aging process validated in the United States, and equivalent to one year spent at room temperature. They were then analyzed using a high-performance mass spectrometer, says Lebaron.
'Initially, there is very little benzophenone in the products. But gradually as the product ages, there is more and more benzophenone,' he told AFP.
'Increases in benzophenone in excess of 100% and even up to 200% were observed,' the biologist adds. 'This is the first time that the degradation of octocrylene into benzophenone has been shown. ' Another argument, according to him, to ban it in personal care products.
Stressing that this substance is easily absorbed by the skin, the researchers believe that octocrylene-based products, and therefore contaminated with benzophenone, can pose a threat to health as well as the environment.