Do Zinc Oxide Nanoparticles Penetrate the Skin or Cause Skin Toxicity?

Zinc oxide is a very effective sunscreen and is used in both chemical and physical barrier sunscreens. The nanoparticle formulation (ZnO-NPs) helps minimize the appearance of zinc on the skin, so it is popular in cosmetic use. There are consumer concerns that nanoparticles may not be safe. A 2017 National Sun Protection Survey by Cancer …