Titanium dioxide nanoparticles may accumulate and cause DNA damage

Solids were stable and did not show visible signs or changes in their spectra after being kept at room temperature for over 60 days. The absorbance at the maximum absorbance wavelength remained unmodified.

Micronized titanium dioxide doesn’t penetrate skin so there’s no need to be concerned about it getting into your body. Even when titanium dioxide nanoparticles are used, the molecular size of the substance used to coat the nanoparticles is large enough to prevent them from penetrating beyond the uppermost layers of skin. This means you’re getting the sun protection titanium dioxide provides with no risk of it causing harm to skin or your body. The coating process improves application, enhances sun protection, and prevents the titanium dioxide from interacting with other ingredients in the presence of sunlight, thus enhancing its stability. It not only makes this ingredient much more pleasant to use for sunscreen, but also improves efficacy and eliminates safety concerns. Common examples of ingredients used to coat titanium dioxide are alumina, dimethicone, silica, and trimethoxy capryl silane.

Zinc oxide. Zinc oxide is a popular cross-linking agent for rubber and for various resins. It is essential in the formulation of solvent-borne polychloroprene adhesives. Furthermore, zinc oxide is a good UV stabilizer, has biocidal activity and has a relatively high refractive index (2.0) which makes it an efficient white pigment. Some typical properties are: density 5.6 g/cm³; particle size 0.036-3 μm; oil absorption 10–20 g/100 g; specific surface area 10–45 m²/g. Zinc oxide is produced by reaction of the metal in the vapour state with oxygen. Zinc oxide is nonporous and is quite pure. Thus, the high surface area of some grades is due to the small particle size of zinc oxide. Some grades, especially for use in the rubber industry, are surface modified by deposition of 0.2-0.4% of stearic acid, propionic acid, or light oil [47].