Titanium Dioxide, also known as TiO2, is a naturally occurring mineral used as a coloring agent, opacifier and a physical sunscreen in cosmetic formulations.
Coloring Agent: It's a white pigment, so it's often used in products like foundations, concealers, and other color cosmetics to create the desired shade when mixed with other pigments.
Opacifier: Titanium dioxide is also used to increase the opacity of cosmetic products, reducing the transparency or translucency and giving them a more substantial, solid appearance. This is particularly useful in products like sunscreens, where it can help visually indicate where the product has been applied and if it's been spread evenly.
Physical Sunscreen: Titanium dioxide is a broad spectrum UV filter, which means it protects the skin from both UVA and UVB rays. Unlike chemical sunscreens which absorb UV light and convert it into heat, titanium dioxide is a physical sunscreen that reflects and scatters the UV light, reducing the amount of radiation that reaches the skin. It is often used in products labeled as "mineral" sunscreens.
In its raw form, titanium dioxide can have a whitish cast on the skin. To avoid this, it is sometimes coated with other materials or used in its nano-sized form, though there is some debate around the safety of nano-particles in cosmetics.