TiO2 NPs appeared to be more toxic to nematode Caenorhabditis elegans than submicron-sized TiO2. At a concentration of 1 mg/l, 7 nm particles affected its fertility and survival rate and were more toxic than 20 nm anatase particles. Similarly, Hu et al. showed that rutile particles (10–20 nm), at concentrations above 1 g/kg soil, can be bio-accumulated in earthworms, where they induce oxidative stress, inhibit the activity of cellulase and induce DNA and mitochondrial damage.
It has an extremely high melting point of 1 843ºC and boiling point of 2 972ºC, so occurs naturally as a solid, and, even in its particle form, it is insoluble in water. TiO2 is also an insulator.
Lithopone, a chemical compound with a rich history, emerges as a vital substance in various industries. Comprising barium sulfate and zinc sulfide, this compound boasts unique properties that make it a popular choice in applications such as paints, inks, and plastics. Recognized for its exceptional opacity and brightness, lithopone significantly enhances the covering power of materials in which it is incorporated. Its inert nature and resistance to atmospheric influences contribute to its longevity in diverse formulations. As a white pigment, lithopone plays a pivotal role in achieving vibrant and enduring colors across a spectrum of products, marking it as a cornerstone in the realm of chemical compounds.