Nanoparticles: why do we use them?

Nanoparticles are very small particles. One nanometre is equal to one billionth of a metre. It is not because they are so small that they pass through the skin.  Isabelle Orquevaux, L’Oréal’s Scientific and Regulatory Director France, explains that it is perfectly safe to use them and necessary for product performance, especially for sunscreens.