An inorganic chemical, titanium dioxide is used as a dye to help products achieve a certain appearance, including whitening a product. Some experts and publications have described it as being akin to a paint primer that's used before the color is added to food in order to give products a uniform shine. Its presence is common in many items beyond Skittles including coffee creamers, cake mixes, and chewing gum. It's also used for pigment and in cosmetics manufacturing.
However, they did find that minor levels of 0.01% were absorbed by immune cells — known as gut-associated lymphoid tissue — and may be delivered to other organs. Currently, it’s unknown how this may affect human health (17Trusted Source).