Titanium dioxide (TiO2) is a chemically inert inorganic compound and an insoluble white solid that occurs naturally in several minerals, including rutile, anatase, and brookite. It is created synthetically from the mineral ilmenite. It is an insoluble white solid. Anatase, when compared to brookite and routine, has the most industrial applications, but it is the most toxic form of TiO2.

Though the regulated use of titanium dioxide in food products is legal in the U.S. and Canada, it's banned in some other countries, notably throughout Europe. In May 2021, the European Food Safety Authority announced that titanium dioxide can no longer be considered safe as a food additive.