The properties of lithopone are very suitable for use in the production of coatings. Because the ingredients of lithopone are zinc sulfide and barium sulfate, and the more zinc sulfide content, the stronger its covering power. This indicates a paint product with strong white covering power. It is different from water in that it reacts with acid but does not react with alkali. It has a wide range of uses. Because its structural properties are similar to titanium dioxide and its price is relatively cheap, it can also be used as a substitute for some titanium dioxide. Lithopone can be used for coloring paints, inks, pigments, rubber, paper, leather, enamel, etc.
On November 23, 2022, the General Court of the European Union reversed the conclusion that titanium dioxide was carcinogenic and released a statement (1,2):
“First, the Commission made a manifest error in its assessment of the reliability and acceptability of the study on which the classification was based and, second, it infringed the criterion according to which that classification can relate only to a substance that has the intrinsic property to cause cancer.”
As part of our mission at CRIS we base our safety assessments on the currently available scientific evidence and consider many variables (e.g., study quality, journal of publication, etc.), even if it goes against previous conclusions. Evidence-informed decisions making is critical to ensure that the laws and regulations put into place are for the benefit of the population.
The EU General Court maintains that the scientific evidence presented wasn’t the complete picture for the ingredient, “in the present case, the requirement to base the classification of a carcinogenic substance on reliable and acceptable studies was not satisfied.”
The aim of this work was to examine particularly the Degussa P25 titanium dioxide nanoparticles (P25TiO2NPs) because they are among the most employed ones in cosmetics. In fact, all kinds of titanium dioxide nanoparticles (TiO2NPs) have gained widespread commercialization over recent decades. This white pigment (TiO2NPs) is used in a broad range of applications, including food, personal care products (toothpaste, lotions, sunscreens, face creams), drugs, plastics, ceramics, and paints. The original source is abundant in Earth as a chemically inert amphoteric oxide, which is thermally stable, corrosion-resistant, and water-insoluble. This oxide is found in three different forms: rutile (the most stable and substantial form), brookite (rhombohedral), and anatase (tetragonal as rutile), of these, both rutile and anatase are of significant commercial importance in a wide range of applications [3]. Additionally, the nano-sized oxide exhibits interesting physical properties, one of them is the ability to act as semiconducting material under UV exposure. In fact, TiO2NPs are the most well-known and useful photocatalytic material, because of their relatively low price and photo-stability [4]. Although, this photoactivity could also cause undesired molecular damage in biological tissues and needs to be urgently assessed, due to their worldwide use. However, not all nanosized titanium dioxide have the same behavior. In 2007, Rampaul A and Parkin I questioned: “whether the anatase/rutile crystal form of titanium dioxide with an organosilane or dimethicone coat, a common titania type identified in sunscreens, is appropriate to use in sunscreen lotions” [5]. They also suggested that with further study, other types of functionalized titanium dioxide could potentially be safer alternatives. Later, Damiani found that the anatase form of TiO2NPs was the more photoactive one, and stated that it should be avoided for sunscreen formulations, in agreement with Barker and Branch (2008) [6,7].
One of the primary uses of titanium dioxide is in the production of pigments for paints, coatings, and plastics. Titanium dioxide is known for its excellent opacity, brightness, and whiteness, making it an ideal choice for creating vibrant and long-lasting colors. Manufacturers of titanium dioxide carefully control the particle size and crystal structure of the pigment to ensure consistent quality and performance.