- Lithopone, a crucial component in the manufacturing of various industrial products, is a mixture of zinc sulfide and barium sulfate. It is widely used as a white pigment in paints, plastics, printing inks, and many other applications due to its excellent opacity and light stability. The global lithopone market, therefore, plays a significant role in the worldwide chemical industry.
A1:
- Scattering is strong when the difference in the refractive index of particle & matrix, Δn = np - nm, is big
The refractive index of binders used in coatings and inks is around 1.55. Titanium Dioxide is preferably used as a scattering source because the pigment does not absorb visible light and it has a high refractive index.- Scattering is strong when the difference in the refractive index of particle & matrix, Δn = np - nm, is big
In summary, the Food Directorate's position is that there is no conclusive scientific evidence that the food additive TiO2 is a concern for human health. This is based on a review of the available scientific data relevant to food uses of TiO2. However, we will continue to monitor the emerging science on the safety of TiO2 as a food additive and may revisit our position if new scientific information becomes available.
Titanium dioxide (TiO2) is considered as an inert and safe material and has been used in many applications for decades. However, with the development of nanotechnologies TiO2 nanoparticles, with numerous novel and useful properties, are increasingly manufactured and used. Therefore increased human and environmental exposure can be expected, which has put TiO2 nanoparticles under toxicological scrutiny. Mechanistic toxicological studies show that TiO2 nanoparticles predominantly cause adverse effects via induction of oxidative stress resulting in cell damage, genotoxicity, inflammation, immune response etc. The extent and type of damage strongly depends on physical and chemical characteristics of TiO2 nanoparticles, which govern their bioavailability and reactivity. Based on the experimental evidence from animal inhalation studies TiO2 nanoparticles are classified as “possible carcinogenic to humans” by the International Agency for Research on Cancer and as occupational carcinogen by the National Institute for Occupational Safety and Health. The studies on dermal exposure to TiO2 nanoparticles, which is in humans substantial through the use of sunscreens, generally indicate negligible transdermal penetration; however data are needed on long-term exposure and potential adverse effects of photo-oxidation products. Although TiO2 is permitted as an additive (E171) in food and pharmaceutical products we do not have reliable data on its absorption, distribution, excretion and toxicity on oral exposure. TiO2 may also enter environment, and while it exerts low acute toxicity to aquatic organisms, upon long-term exposure it induces a range of sub-lethal effects.
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.
Some food products will include titanium dioxide on their nutrition label. But again, it can be hard to tell for those who don't list the ingredient.