One of the most common worries about titanium dioxide is that it could be a cancer-causing agent. The link between cancer and titanium dioxide traces back to a 1985 study where rats were exposed to high levels of titanium dioxide for two years, causing lung cancer. However, not all experts are convinced by this study.

Titanium dioxide (TiO₂) is a naturally occurring mineral that is mined from the earth, processed and refined, and added to a variety of foods, as well as other consumer products. White in color, it is used to enhance the color and sheen of certain foods and is also key for food safety applications. In its natural state it exists in different bulk crystalline forms, such as anatase and rutile, but during processing it is ground into a very fine powder.