Not only is O.Šun made from all-natural ingredients, but we also only use Zinc Oxide in its non-nano form. This means that the particles of Zinc Oxide are bigger than 100nm and therefore the safest option for marine life and coral reefs. This is because the particles are too big to penetrate through marine wildlife's skin or the membranes of marine organisms. Non-nano Zinc Oxide is also the safest form of UV protection for humans too.