lithopone and titanium dioxide factories

Lithopone was discovered in the 1870s by DuPont. It was manufactured by Krebs Pigments and Chemical Company and other companies. The material came in different seals, which varied in the content of zinc sulfide. Gold seal and Bronze seals contain 40-50% zinc sulfide, offering more hiding power and strength. Although its popularity peaked around 1920, approximately 223,352 tons were produced in 1990. It is mainly used in paints, putty, and in plastics.

...

In various industries such as paints, coatings, plastics, and cosmetics, the pH of titanium dioxide must be carefully controlled to achieve the desired performance. In the paint and coatings industry, for instance, titanium dioxide is used as a pigment to provide opacity and brightness to the final product
titanium
titanium dioxide ph. By optimizing the pH of titanium dioxide in the paint formulation, manufacturers can ensure uniform dispersion and excellent coverage, resulting in a high-quality finish.

...

The main concern with nanoparticles is that they are so tiny that they are absorbed into the skin more than we want them (ideally sunscreen should remain on the surface of the skin). Once absorbed they might form unwanted complexes with proteins and they might promote the formation of evil free radicals. But do not panic, these are concerns under investigation. A 2009 review article about the safety of nanoparticles summarizes this, to date, in-vivo and in-vitro studies have not demonstrated percutaneous penetration of nanosized particles in titanium dioxide and zinc oxide sunscreens. The English translation is, so far it looks like sunscreens with nanoparticles do stay on the surface of the skin where they should be.  

...