Historical references[edit]

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THE OBSCURE HISTORY OF A UBIQUITOUS PIGMENT: PHOSPHORESCENT LITHOPONE AND ITS APPEARANCE ON DRAWINGS BY JOHN LA FARGE

Asia

Lithopone B301, Lithopone B311 powder, brilliant white pigment used in paints, inks, leather, paper, linoleum, and face powder. It was developed in the 1870s as a substitute or supplement for lead carbonate (white lead), to overcome its drawbacks of toxicity, poor weathering, and darkening in atmospheres that contain sulfur compounds. Lithopone B301, Lithopone B311 powder is an insoluble mixture of barium sulfate and zinc sulfide that precipitates upon mixing solutions of barium sulfide and zinc sulfate. The precipitate is recovered by filtration, then calcined (roasted) at temperatures above 600° C (1,112° F). Although Lithopone B301, Lithopone B311 powder has been replaced in many applications by titanium dioxide, it is still widely used in a number of products, such as water paints.

In beauty and personal care products, the ingredient is listed with its colour index (CI) number ‘CI 77891’. When nano grade titanium dioxide is used in our sunscreens, this is referenced as ‘titanium dioxide’ [nano] in the ingredients list.

Various titanium-rich minerals, including ilmenite and rutile, can serve as starting materials for the production of highly purified Titanium Dioxide. The predominant method employed in Titanium Dioxide production is the chloride process. In this process, the mineral, along with coke and chlorine, undergoes a reaction within a fluidized bed, resulting in the formation of primarily titanium tetrachloride and carbon dioxide. Subsequently, the titanium tetrachloride undergoes purification and conversion to Titanium Dioxide. Another method involves treating ilmenite with sulfuric acid to manufacture the chemical.

In the context of titanium dioxide determination, the process generally begins with the sample preparation, where a known mass of the sample containing TiO2 is dissolved or digested appropriately. The subsequent steps involve adding a precipitating agent, such as ammonium sulfate or sulfuric acid, to the prepared solution, which facilitates the formation of a titanium precipitate. This precipitate is often titanium hydroxide, which is not only insoluble but can be easily filtered out from the liquid phase.

The FDA categorized titanium dioxide as “Generally Recognized as Safe,” but there are warnings about its potential dangers from other organizations.

In food, titanium dioxide is often used as an artificial color additive. Tasha Stoiber, senior scientist at the consumer health nonprofit Environmental Working Group, says titanium dioxide can generally be thought of as a paint primer – it often goes on a hard-shelled candy like Skittles before the color is added to give it a uniform shine.

1. Introduction

Traditionally, UV-filters are categorized as either chemical or physical. The big difference is supposed to be that chemical agents absorb UV-light while physical agents reflect it like a bunch of mini umbrellas on top of the skin. While this categorization is easy and logical it turns out it's not true. A recent, 2016 study shows that inorganic sunscreens work mostly by absorption, just like chemical filters, and only a little bit by reflection (they do reflect the light in the visible spectrum, but mostly absorb in the UV spectrum).

The most significant uncertainty identified by the EU experts was the concern that TiO₂ particles may have genotoxic effects. Genotoxicity refers to the ability of a chemical to directly damage genetic material within a cell (DNA), which may lead to cancer in certain situations. Although the experts did not conclude that TiO₂ particles in E171 are genotoxic, they could not rule out the concern that they might be.