Titanium (IV) dioxide (TiO2) is one of the most well-known and commercially important inorganic pigments. It is used to provide white color and opacity to paints and coatings, plastics, paper, inks, food products and pharmaceuticals. While TiO2 is often incorporated as a colorant and an opacifier in cosmetics and personal care products, its most important applications are as a sunscreen active and as a component of specialty pigments for color cosmetics. Both the INCI and established drug names for TiO2 are titanium dioxide; however, when used as a colorant in the EU, it is identified by the Colour Index (CI) number 77891.1
Chemistry and Manufacture
TiO2 is a naturally occurring mineral found in three forms: anatase, brookite and rutile, which differ by crystal structure and the number of titanium and oxygen atoms per unit cell of the crystal lattice.2 These TiO2 forms also differ by density, hardness and refractive index due to the differences in their structure. The TiO2 found in nature contains small amounts of impurities such as iron, chromium or vanadium; therefore, it must be chemically refined to obtain the high purity required for most applications, including cosmetics and personal care. TiO2 also may be derived from the naturally occurring mineral ilmenite, a crystalline iron titanium oxide (FeTiO3). In this case, the ilmenite ore must be smelted to remove the iron oxides before the remaining titaniferous slag can be converted into TiO2.