The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
Historically, the first mentions of zinc sulfide being utilized as a pigment were approximately sixty years before the everyday use of lithopone. Originally, it was thought to be appropriate for coloring rubber. In England, a patent was granted for this process. Two decades after this, the focus shifted to zinc sulfide as a suitable pigment for paint. The year 1874 witnessed the patenting of a manufacturing process for a novel white pigment composed of zinc sulfide and barium sulfate. Dubbed Charlton white or Orr’s white enamel, this began a new era for white pigments.
Scrap zinc or concentrated zinc ores are dissolved in sulfuric acid, the solution is purified and the two solutions are reacted. A heavy mixed precipitate results that is 28 to 30% zinc sulfide and 72 to 70% barium sulfate.
Some websites maintain titanium dioxide is inferior to zinc oxide, another mineral sunscreen ingredient whose core characteristics are similar to those of titanium dioxide. The reality is that titanium dioxide is a great broad-spectrum SPF ingredient and is widely used in all manner of sun-protection products. What gets confusing for some consumers is trying to decipher research that ranks sunscreen ingredients by a UV spectrum graph. By most standards, broad-spectrum coverage for sunscreen ingredients is defined as one that surpasses 360 nanometers (abbreviated as “nm” - how the sun’s rays are measured). Titanium dioxide exceeds this range of protection, but depending on whose research you read, it either performs as well as or slightly below zinc oxide.