EU ban on titanium dioxide
Due to its low binder requirement, lithopone provides paints with good flow and application properties. In the plastic processing industry, it is added to plastics to increase the plastic product’s UV tolerance, thus increasing its outdoor life. In the leather industry, it is one of the sulfide-based white pigments. It is also used in the production of linoleum floorings.
This article discusses the discovery of phosphorescent lithopone on watercolor drawings by American artist John La Farge dated between 1890 and 1905 and the history of lithopone in the pigment industry in the late 19th and early 20th centuries. Despite having many desirable qualities for use in white watercolor or oil paints, the development of lithopone as an artists’ pigment was hampered by its tendency to darken in sunlight. Its availability to, and adoption by, artists remain unclear, as colormen's trade catalogs were generally not explicit in describing white pigments as containing lithopone. Further, lithopone may be mistaken for lead white during visual examination and its short-lived phosphorescence can be easily missed by the uninformed observer. Phosphorescent lithopone has been documented on only one other work-to-date: a watercolor by Van Gogh. In addition to the history of lithopone's manufacture, the article details the mechanism for its phosphorescence and its identification aided by Raman spectroscopy and spectrofluorimetry.
Fig. 8. Selected images of skin stratus treated with P25TiO2NPs 10% (left) and VitaminB2@P25TiO2NPs 10% (right) under light, showing no penetration of the nanoparticles (white arrows) beyond the outer stratum corneum.
A safety review conducted by the EFSA in 2021 assessed thousands of studies published on titanium dioxide.