TiO₂ is also used in oral pharmaceutical formulations, and the Pharmaceutical Excipients handbook considers nano-sized TiO₂ a non-irritant and non-toxic excipient. Despite the fact that TiO₂ submicron- and nano-sized particles are widely used as food and pharmaceutical additives, information on their toxicity and distribution upon oral exposure is very limited.

Color, compared with standard samples

Although barium sulfate is almost completely inert, zinc sulfide degrades upon exposure to UV light, leading to darkening of the pigment. The severity of this UV reaction is dependent on a combination of two factors; how much zinc sulfide makes up the pigments formulation, and its total accumulated UV exposure. Depending on these factors Lithopone B301, Lithopone B311 powder itself may vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant might be used, like small amount of cobalt salts, which would be added to the formulation. This process creates cobalt-doped zinc sulfide. The cobalt salts help to stabilize zinc sulfide so it will not have as severe a reaction to UV exposure.

A legal additive in the United States, titanium dioxide is used in everything from food to consumer goods and the U.S. Food and Drug Administration says regulated use of the product as a color additive in food is safe within certain restrictions.

It’s produced through the sulfate or chloride process, which both involve treating titanium ore with sulfuric or hydrochloric acid to produce titanium sulfate or titanium chloride. These materials are then further processed to remove impurities and produce titanium dioxide in its final form.