Recent analyses of food-grade TiO₂ samples have found that a significant portion of particles may be within the nanoscale. These particles (also known as nanoparticles) range in size from 1 to 100 nm, where 1 nm equals 1 billionth of a metre (the width of a typical human hair is 80,000 to 100,000 nm).

Lithopone is a white pigment that is commonly used in a variety of industries, including the paint, plastic, and rubber industries. With 30% of the world's lithopone factories located in China, the country plays a significant role in the production and supply of this important chemical compound.

In a study published in the journal Toxicology, researchers examined the effects of exposing human colon cancer cell line (HTC116) titanium dioxide food additives in vitro. “In the absence of cytotoxicity, E171 was accumulated in the cells after 24 hours of exposure, increasing granularity and reactive oxygen species, inducing alterations in the molecular pattern of nucleic acids and lipids, and causing nuclei enlargement, DNA damage and tubulin depolymerization,” the scientists wrote. Researchers removed the additive from the culture, then examined the results 48 hours later. They found, “The removal of E171 was unable to revert the alterations found after 24 h of exposure in colon cells. In conclusion, exposure to E171 causes alterations that cannot be reverted after 48 h if E171 is removed from colon cells.”

Here it has been shown that functionalization of P25TiO2NPs with vitamin B2 was able to significantly decrease the oxidative stress produced when they are exposed to sunlight. This finding is of main importance to prevent skin damage and toxicity of sunscreens containing this form of untreated titanium dioxide and should be taken into consideration when updating the regulations mentioned above .

Fig. 2. SEM micrograph and EDS map of the same area of a vitaminB2@P25TiO₂NPs.

In recent years, environmental concerns have shaped the way lithopone is produced and used. Suppliers are now more attentive to the sustainability aspect of their operations, ensuring that lithopone is sourced from eco-friendly processes. Many suppliers have adopted responsible mining practices and have invested in technologies that reduce waste and emissions during production. This shift not only appeals to environmentally-conscious consumers but also helps manufacturers comply with stringent regulations regarding product safety and environmental impact.

All About Titanium Dioxide Pigment