if you compare the levels—which went as high as 50,000 milligrams/killigrams per day— to what humans are actually exposed to, we're talking orders of magnitude. It was a huge amount, Norbert Kaminski, PhD, a professor of pharmacology & toxicology and director of the Center for Research on Ingredient Safety at Michigan State University told Health.

Some websites maintain titanium dioxide is inferior to zinc oxide, another mineral sunscreen ingredient whose core characteristics are similar to those of titanium dioxide. The reality is that titanium dioxide is a great broad-spectrum SPF ingredient and is widely used in all manner of sun-protection products. What gets confusing for some consumers is trying to decipher research that ranks sunscreen ingredients by a UV spectrum graph. By most standards, broad-spectrum coverage for sunscreen ingredients is defined as one that surpasses 360 nanometers (abbreviated as “nm” - how the sun’s rays are measured). Titanium dioxide exceeds this range of protection, but depending on whose research you read, it either performs as well as or slightly below zinc oxide.