TiO₂ is added to lotions, creams and various cosmetics as a whitening agent and acts as a sunscreen. ZnO is added as a sunscreen and is very effective at blocking UV light. Its concentration is a factor in determining the SPF (sun protection factor) of lotions and creams. ZnO is also a mild astringent with mild antiseptic properties used in lotions and creams to help retail moisture and provide a protective layer to the skin and to prevent diaper rash in baby products. When iron oxide (Fe₂O₃) is also added the TiO₂ (white) and Fe₂O₃ (red) are blended in various proportions to create the many shades of reds and browns in cosmetics, make-up, rouge and lipsticks.