They are the only two sunscreen ingredients classified by the FDA as safe and effective. And though titanium dioxide is usually used in mineral sunscreens in the form of nanoparticles, evidence suggests that few, if any, particles penetrate the skin.

For research published in 2022 study in the journal Food and Chemical Toxicology, scientists examined “the genotoxicity and the intracellular reactive oxygen species induction by physiologically relevant concentrations of three different TiO2 nanomaterials in Caco-2 and HT29-MTX-E12 intestinal cells, while considering the potential influence of the digestion process in the NMs’ physiochemical characteristics.” They found a “DNA-damaging effect dependent on the nanomaterial,” along with the micronucleus assay suggesting “effects on chromosomal integrity, an indicator of cancer risk, in the HT29-MTX-E12 cells, for all the tested TiO2 nanomaterials.” Researchers concluded that the results showcase “evidence of concern” regarding titanium dioxide used as a food additive.

Lithopone is an inorganic white pigment, obtained from co-precipitation of Zinc sulfide (ZnS) and Barium sulfate (BaSO4). As a white pigment, it acts as a cost-effective alternative for TiO2. Some of the properties of Lithopone include high brightness and performance under UV exposure. Lithopone requires less wetting agent to achieve optimum wetting of its surface. It is commercially graded on the basis of amount of ZnS. Its grades include 28%, 30%, and 60% ZnS. As a comparatively inexpensive white pigment, Lithopone is presently used in various paint formulations, road marking paints, jointing compounds, and putties.