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.

There’s also concern that exposure to the mineral over time, even in small amounts, can build up in the body, particularly in the kidneys, spleen and liver. Although most of the mineral is excreted in feces, there is evidence that a small percentage may remain in bodily organs.

If you want to avoid titanium dioxide, Stoiber and Faber urge consumers to try and avoid processed foods as best as you can.