Relative Density Among commonly used white pigments, lithopone has the smallest relative density. Among white pigments of the same mass, titanium dioxide has the largest surface area and the highest pigment volume.

Although cosmetics are not meant for consumption, there are concerns that titanium dioxide in lipstick and toothpaste may be swallowed or absorbed through the skin.

1. What is titanium dioxide?

In a 2016 study published in Scientifica (Cairo), Egyptian researchers examined the effects of titanium dioxide nanoparticles on the organs of mice by orally administering the food additive daily, for five days. The results showed that the exposure produced “mild to moderate changes in the cytoarchitecture of brain tissue in a time dependent manner.” Furthermore, “Comet assay revealed the apoptotic DNA fragmentation, while PCR-SSCP pattern and direct sequencing showed point mutation of Presenilin 1 gene at exon 5, gene linked to inherited forms of Alzheimer’s disease.” The researchers wrote: “From these findings, “the present study concluded that TiO2NPs is genotoxic and mutagenic to brain tissue which in turn might lead to Alzheimer’s disease incidence.”

Currently, titanium dioxide as a food additive is classified as GRAS, or “generally recognized as safe.”