Zinc oxide is used as a bulking agent and a colorant. In over-the-counter drug products, it is used as a skin protectant and a sunscreen. Zinc oxide works as a sunscreen by reflecting and scattering UV radiation. Sunscreens reduce or prevent sunburn and premature aging of the skin.
The U.S. Food and Drug Administration (FDA) has conducted extensive reviews of the safety of zinc oxide for use as a color additive in drugs and cosmetics and as a sunscreen and skin protectant active ingredient and has stated that zinc oxide may be safely used in cosmetics. FDA also has also approved the use of zinc oxide for use in over-the-counter skin protectants at concentrations up to 25 percent, and in sunscreen drug products at concentrations up to 25 percent.