Zinc Oxide (ZnO) is powdered, oxidized zinc derived from the naturally occurring mineral, zincite, and routinely used in a wide range of consumer products. When used in sunscreen products, ZnO acts as a physical block to the sun's ultraviolet (UV) radiation, helping to reduce or prevent sunburn and premature aging of the skin. Preventing sunburn is an important factor in reducing skin cancer risk. Zinc oxide is the broadest spectrum UVA and UVB reflector approved for use as a sunscreen by the FDA and is allowed in concentrations up to 25%. When used as an ingredient in sunscreen, zinc oxide screens both UVA (320–400 nm) and UVB (280–320 nm) rays of ultraviolet light.