What is an exposure route? 

Benefits of Lithopone Powder:

The European Commission banned titanium dioxide as a food additive in the EU in 2022 after the European Food Safety Authority (EFSA) conducted an updated safety assessment of E171 and concluded the panel could not eliminate concerns about its genotoxicity. 

The lack of clear regulations and controls explains that P25TiO₂NPs are still found in many of the commercialized sunscreens in the market. Some of them are coated to reduce the photoactivity of the anatase form, which is known to be responsible for tissue damage, but not enough studies were made on these coated forms. The anatase photoactivity could trigger the production of reactive oxygen species (ROS) generation, as it was stated before. The ROS are chemically reactive species containing oxygen, such as peroxides, superoxide, hydroxyl radical, and singlet oxygen. They are regularly produced in the biological milieu and counterbalanced by physiological antioxidant defense mechanisms. However, an abrupt increase of ROS may result in non-reversible damage to the skin cells. The effects of coated and uncoated P25TiO₂NPs need therefore to be studied, and articles on this topic present different conclusions. [11], [12], [13] Recent literature on this topic found that TiO₂NPs inhalation provokes serious genotoxicity and DNA damage [14], [15], [16], [17]. On the other hand, some studies in rats have reported no significant harm to genetic material [18], [19], [20], [21], [22].

Another important property of Chinese anatase titanium dioxide is its photocatalytic activity, which enables it to break down organic pollutants and harmful chemicals when exposed to light. This makes it an attractive choice for applications in environmental remediation, such as air and water purification systems. Additionally, its photocatalytic properties have also been studied for use in self-cleaning surfaces, such as windows and building facades, where it can help to reduce maintenance costs and keep surfaces looking clean.

Pendant longtemps on a reproché au lithopone sa mauvaise tenue à l'extérieur, due à la dégradation photolytique du sulfure de zinc et/ou à la présence de traces de chlore, provoquant un noircissement du revêtement. Même si la recherche a permis d'éradiquer en grande partie ce problème, on réserve son emploi dans les peintures intérieures pour les raisons suivantes :

Avoiding exposure

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.

To overcome this challenge, manufacturers use advanced technology and processes to monitor and control the buff percentage of their products. This may involve the use of sophisticated equipment to measure the coating thickness of titanium dioxide particles, as well as automated systems to adjust the level of coating as needed. By carefully controlling the buff percentage, manufacturers can ensure that their products meet the specifications of their customers and maintain a high level of quality and performance.