The element titanium and the compound TiO₂ are found around the world, linked to other elements such as iron, in several kinds of rock and mineral sands (including a component of some beach sands). Titanium most commonly occurs as the mineral ilmenite (a titanium-iron oxide mineral) and sometimes as the mineral rutile, a form of TiO₂. These inert molecular compounds must be separated through a chemical process to create pure TiO2.

In general, nanoparticles have been shown to accumulate in the body, particularly in organs in the gastrointestinal tract, along with the liver, spleen, and capillaries of the lungs.