Lithopone is manufactured by a process (Fig. 1) in which barium sulfide solution is prepared by reducing barite ore (BaSO 4) with carbon and leaching the resulting mass.
A dense, white, opaque pigment composed of a mixture of Zinc sulfide (30%) and Barium sulfate (70%) with trace amounts of Zinc oxide. Lithopone, first produced in 1874, was called Orr's white. The mixture of the two components is so intimate that it is hard to distinguish microscopically. Lithopone is an inert, transparent pigment which is often used as a filler or as a base for lake pigments. Lithopone was widely used in house paints in the first half of the 20th century. It was also used for some artist grounds, inks and as a filler in Paper, Leather, and Linoleum. Now lithopone has mostly been replaced by Titanium dioxide.
All samples (n = 6) were irradiated in a 96 well plate using an LED panel on top for 3 and 6 h before analysis. An identical set of samples were kept in the dark as controls. The temperature was checked and did not go over 37 °C. The intensity of light was also measured and was constant at 19,500.10 lux. (43.33 W in 0.2 m2), about 5 times less than actual solar light intensity on Earth's surface Therefore, these findings are indicative of even greater danger in real life.
Titanium dioxide R-5566 can be widely used in indoor and outdoor coatings, latex paints, powder coatings, inks, papermaking, rubber, plastics, masterbatches.
