For that reason, the Center for Science in the Public Interest has graded titanium dioxide as a food additive that consumers should seek to “avoid.” Scientists at the nonprofit nutrition and food safety watchdog group today published a new entry for titanium dioxide in its Chemical Cuisine database of food additives.  

On the other hand, the U.S. Food and Drug Administration (FDA) in their Final Administrative Order on Sunscreen Drug Products posted in September 2021 still accepts titanium dioxide up to 25% in the list of Generally Recognized As Safe and Effective (GRASE) in the main document, without further clarification on what kind or size of particles [9]. However, on page 24 (Sunscreen containing nanomaterials) FDA clearly “distinguish nanomaterials from other forms of these ingredients'' (zinc oxide and titanium dioxide) and ask for comments on “any particular nanomaterials that you believe should not be permitted for use in OTC sunscreen products”. To the best of our knowledge, this Agency did not ban the use of nanoparticulate titanium dioxide in any form, even though it is mentioned on page 34 that the anatase form is the more photoactive one, due to the lack of evidence with real sunscreens OTC (over the counter) in vivo. Moreover, other regulations in Latin America (MERCOSUR agreement, 2006) do not state clearly their position on the use of nanoparticulate TiO₂NPs [10].

It's hard to determine the total amount of food products that have titanium dioxide because federal regulations don't require all producers to list its use on ingredient labels, but the list of foods containing the substance certainly doesn't end with Skittles.