Skin permeation study of UV filters in cosmetics

Ultraviolet (UV) filters reduce the transmission of radiation through the skin. By remaining on the surface of the skin, they offer protection against UV rays emitted by the sun. These molecules can penetrate the skin. This depends on their physical and chemical properties, the formulation (i.e., the composition of the cream or lotion), and the condition of the skin.

UV filters are recognized as endocrine disruptors and are therefore toxic to reproduction. The ability of these substances to cross the skin barrier and induce potential toxicity in humans has not yet been clearly defined.

The ability of a molecule to penetrate the skin is studied using in vitro skin permeation experiments. This study will enable us to understand whether the most widely marketed UV filters in Europe, which are present in our cosmetics, are capable of crossing the skin barrier. And if so, at what concentration we might potentially find them in the different layers of the skin or directly in the blood. We will thus be able to classify substances according to their skin absorption capacity and link this to their endocrine disrupting activity.

Thanks to this classification, the general public as well as professionals will be able to choose the cosmetic(s) to use with the least risk to health. This new classification could be added, for example, to existing applications as additional information.