Scientists at the Sorbonne University in France have shown that popular brands of sunscreens build up over time a substance called benzophenone, which can cause cell mutations, cancer and endocrine disorders. The researchers presented their findings in an article published in the journal Chemical Research in Toxicology.
Experts have determined benzophenone concentrations in 17 sunscreens from nine French manufacturers, including Nivea, Garnier, LaRoche-Posay, and eight American firms, including Coppertone, Banana Leaf and Neutrogena. All products except Nivea contained octocrylene, which absorbs ultraviolet radiation. Samples of creams were stored in an incubator for six weeks at 40 degrees Celsius at 75 percent relative humidity. This corresponds to the storage of the cream for a year at room temperature.
All 16 octocrylene-containing creams were found to have benzophenone at concentrations ranging from six to 186 micrograms per kilogram. Benzophenone is produced from octocrylene through a retroaldol condensation reaction. Moreover, 70 percent of the benzophenone contained in creams can be absorbed through the skin.
The authors of the study argue that the circulation of funds with octocrylene should be banned until proven safe.
