Some consumer advocacy groups and health agencies — particularly, those at the Environmental Working Group — have been pushing federal officers at the Food and Drug Administration (FDA) to reconsider their existing rules on the additive, which is commonly found in processed snacks and sweets.

Titanium dioxide has many purposes in both food and product development.

The EU expert panel did not identify an immediate health concern linked to TiO₂ when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO₂ nanoparticles, the panel concluded that TiO₂ as a food additive (E171) could no longer be considered safe.

Lithopone’s historical significance is further accentuated by the advancements and modifications that followed its inception. The 1874 patent by J.B. Orr, for instance, ushered in a new white pigment—Orr’s Zinc White. This innovation was attained by co-precipitating zinc sulfate and barium sulfide, followed by a calcination process. Further refinements marked the subsequent decades, the most notable being the enhancement of lightfastness achieved in the 1920s by introducing small amounts of cobalt salts before calcination.

While the FDA maintains that the regulated use of titanium dioxide is safe, the European Food Safety Authority and some other experts warn of potential, serious health risks.

While the FDA maintains that the regulated use of titanium dioxide is safe, the European Food Safety Authority and some other experts warn of potential, serious health risks.

The major restraint to the global Lithopone market is the availability of numerous white pigment substitutes. It can be replaced by other inorganic white pigments such as Titanium Dioxide (TiO2) and Sachtolith. Among these substitutes, the introduction of TiO2 has reduced the commercial importance of Lithopone white pigment. Compared to other white pigments, TiO2 has high brightness and refractive index, which results in lower pigment loading. 

The presence of so many lithopone factories in China has also led to advancements in production technology and quality control. Chinese manufacturers have invested heavily in research and development to improve the performance of their lithopone products, leading to higher quality and more consistent products on the market. This has helped to cement China's reputation as a leading producer of lithopone on the global stage.

No acute effects of nano-sized TiO₂ were observed in Danio rerio (zebrafish) embryos. Exposure of rainbow trout to TiO₂ NPs triggered lipid peroxidation, influence on the respiratory tract, disturbance in the metabolism of Cu and Zn, induction of intestinal erosion  and accumulation in kidney tissue. Linhua et al. exposed juvenile carp to 100 and 200 mg/ml of particles and TiO₂ observed no mortality. However, the fish suffered from oxidative stress and pathological changes in gill and liver. In the infaunal species Arenicola marina, exposure to TiO₂ NPs in sediment caused sub-lethal effects including decrease in casting rate and increase in cellular and DNA damage. Aggregated particles were visible in the lumen of the gut, but no uptake through the gut or the skin was observed.

Sulphate process. The ilmenite is reacted with sulphuric acid giving titanium sulphate and ferric oxide. After separation of ferric oxide, addition of alkali allows precipitation of hydrous titanium dioxide. The washed precipitate is calcined in a rotary kiln to render titanium dioxide. The nucleation and calcination conditions determine the crystalline structure of titanium dioxide (e.g. rutile or anatase).

In addition to its pharmaceutical applications, barium sulphate is extensively utilized in the production of paints and coatings, where a bright white pigment is essential. The opacity and brightness provided by barium sulphate make it a popular choice in formulations for white and colored paints. Its non-toxic nature and excellent stability enhance its appeal in these products.

Biointerfaces, Biomimicking, and Biohybrid Systems

Declaration of Competing Interest

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 the pigment itself can vary in shade over time, ranging from pure white all the way to grey or even black. To suppress this effect, a dopant may be used, such as a 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 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.