However, humans are not exposed to E171 in drinking water at any significant quantity over a long duration, so this potential effect is irrelevant to the human experience. It’s important to understand that a potential hazard is not the same thing as an actual risk. 

Where It’s Hiding

A 2022 review on past studies of titanium dioxide and rat lung cancer, for instance, said the original study was under extreme conditions and its effects were not replicated in other animal species. Additionally, the review concluded that the few studies which did directly focus on titanium dioxide's impact on humans did not end up showing any increased cancer risk.

Nano, or ultrafine, TiO₂ comprises primary particles sized less than 100nm. In this grade, titanium dioxide is transparent (colourless) and boasts improved UV scattering and absorbing properties compared with larger particle-size pigmentary TiO₂.

Nanotoxicology 

When asked about the recent Skittles lawsuit, the FDA said the agency does not comment on pending litigation.

Other food products that list titanium dioxide are Lucerne cottage cheese, Beyond Meat's chicken plant-based tenders, Great Value ice cream and Chips Ahoy! cookies.

That being said, most experts tell us that these potential health risks shouldn’t trouble us, because titanium dioxide has been used in the market for decades, and no adverse reactions have been reported by users. The bottom line is that when used correctly, titanium dioxide should be a safe ingredient that’s safe for all skin types, every day