1. What is titanium dioxide?

Having thus described the origin and uses of the pigment, we now come to the question, what is lithopone? It is, in short, a chemical compound usually consisting of 30.5 per cent zinc sulphide, 1.5 per cent zinc oxide and 68 per cent barium sulphate, but these proportions vary slightly in the different makes. Lithopone of this composition is sold as the highest grade, either as red seal or green seal, as it best suits the idea of the manufacturer. Many manufacturers, especially in Europe, sell and also export other brands under other seals, containing 24, 20, 18 and as little as 12 per cent of zinc sulphide with very small percentages of zinc oxide, the balance being usually barium sulphate, but sometimes certain portions of China clay or gypsum (calcium sulphate) or whiting (calcium carbonate). Such brands are not a chemical compound, but mechanical mixtures of the chemically compounded lithopone and the admixtures referred to.

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. 

According to the EFSA's Expert Panel on Food Additives and Flavorings 2021 opinion regarding titanium dioxide, it could not rule out a concern for genotoxicity from ingestion of the material based on a perceived gap in data on this risk, which serves as the basis for current ban, said a March report on the decision.