However, since it’s photosensitive — meaning it can stimulate free radical production — it’s usually coated in silica or alumina to prevent potential cell damage without reducing its UV-protective properties (7Trusted Source).

In food, titanium dioxide is often used as an artificial color additive. Tasha Stoiber, senior scientist at the consumer health nonprofit Environmental Working Group, says titanium dioxide can generally be thought of as a paint primer – it often goes on a hard-shelled candy like Skittles before the color is added to give it a uniform shine.