Titániumdioxid

Titániumdioxid, also known as titanium dioxide (TiO2), is an inorganic compound widely used as a white pigment. It occurs in nature as minerals such as ilmenite and rutile, but most industrial TiO2 is produced synthetically. The two principal crystalline forms are anatase and rutile; rutile is more chemically stable and gives better opacity, while anatase is often used in specialized applications and can transform to rutile with heat.

TiO2 pigments have a very high refractive index, which makes them exceptionally effective at scattering light and producing brightness and opacity. Pigment-grade TiO2 is manufactured by sulfate or chloride processes from titanium-containing ores and is milled to achieve the desired particle size and dispersion. The material is chemically inert and non-flammable, contributing to its versatility in various media, including paints, coatings, plastics, and paper, as well as in ceramics and inks.

Common applications include interior and exterior paints, coatings for automobiles and construction products, plastics formulations, paper whitening, and cosmetics, including sunscreens where TiO2 acts as a UV filter. In some regions TiO2 has been used as a food additive (E171) for whitening, but regulatory restrictions have increased due to safety concerns about nanoparticle forms.

Safety and regulation: TiO2 is generally stable and inert, but inhalation of fine TiO2 powder can irritate the respiratory tract. The International Agency for Research on Cancer classifies titanium dioxide as possibly carcinogenic to humans (Group 2B) for inhalation exposure in occupational settings. Regulatory status varies by region and application; consumer products typically pose minimal risk when used as intended, though nanoparticle considerations continue to be studied.