Titanium dioxide (TiO2) is a fine white powder or dust that occurs naturally. It was first intentionally produced for use as a white pigment in 1923.
It is naturally opaque and bright, which makes it useful for use in paper, ceramics, rubber, textiles, paints, inks, and cosmetics. It is also resistant to ultraviolet (UV) light and is used widely in sunscreens and pigments that are likely to be exposed to UV light. It is used in a wide variety of personal care products, including color cosmetics such as eye shadow and blush, loose and pressed powders, and sunscreens.
Titanium dioxide can form several different shapes, which have different properties. Some shapes can be converted to nanomaterials. Micronized TiO2 (also called "nano" or "nanoparticles") was introduced in the early 1990s. Nanotechnology and micronization both refer to the practice of creating very small particle sizes of a given material. "Nanoparticles" usually refers to particles smaller than 100 nanometers; a nanometer is 1/1 billionth of a meter. At these small sizes, and at low concentrations, titanium dioxide appears transparent, allowing for effective sunscreens that do not appear white.
Titanium dioxide, or TiO2, will be listed on product labels, but companies are not required to list ingredient size or structure. When it is used in sunscreens to block UV light, titanium dioxide is considered an active ingredient, which means the concentration must also be listed.
