Because of their small size, nanoparticles may have unique physical and chemical properties. These properties may cause them to interact with living systems differently than larger materials with the same chemical composition (also known as bulk materials).

There are many uses of titanium dioxide that we don't know about because they were made exempt from being on the package in 1977, said Faber, who added that nothing much has changed since – other than the FDA approving some other uses of the color additive, such as expanding the use of mica-based pearlescent pigments (prepared from titanium dioxide) as color additives in distilled spirits over recent years.

Total zinc and barium sulphate

A 2012 study published in the journal Environmental Science & Technology noted that children are especially exposed to titanium dioxide because of the food that contains the food additive and is particularly marketed to children, including candy and cakes.