Titanium dioxide does not penetrate the skin

Nanoparticles provide effective protection against UV radiation

Evonik's studies show that this is not a health hazard because titanium dioxide does not penetrate healthy skin If it is applied in a water-in-oil emulsion, titanium dioxide is only found in the statum corneum, the uppermost layer of the outer skin (epidermis). Although traces of titanium dioxide are found on the upper hair follicles, they are not found in the live tissue around the hair follicles.

The epidermis acts as a barrier which prevents nanostructured titanium dioxide penetrating to the next layer (dermis). So, as long as the skin is not injured, nanostructured titanium dioxide cannot enter the blood supply and become distributed in the body. These findings were published in 2006 by the EU's Nanoderm project, which was set up to conduct a risk evaluation of nanostructured particles in cosmetics, and corroborated by a second report published by industrial scientists. (A.O. Garmer, E. Leibold, B. van Ravenzwaay, Toxicology in Vitro 20 [2006] 301-307.)