Zinc oxide is a white powder that naturally occurs on the outside of zinc metal when it is exposed to oxygen and water. A mild astringent and topical protectant with some antiseptic action. It is also used in bandages, pastes, ointments, dental cements, and as a sunblock. Zinc oxide is a natural sun protecting (SPF) mineral that blocks harmful UV rays. It also soothes irritated skin due to its anti-inflammatory properties and closes fissures due to its astringency.