In vitro, in the hemocytes of the marine mussel Mytilus hemocytes, suspension of TiO₂ NPs (Degussa P25, 10 μg/ml) stimulated immune and inflammatory responses, such as lysozyme release, oxidative burst and nitric oxide production. Vevers and Jha demonstrated the intrinsic genotoxic and cytotoxic potential of TiO₂ NPs on a fish-cell line derived from rainbow-trout gonadal tissue (RTG-2 cells) after 24 h of exposure to 50 μg/ml. Reeves et al. demonstrated a significant increase in the level of oxidative DNA damage in goldfish cells, and suggested that damage could not repaired by DNA repair mechanisms. Another suggestion from the mentioned study was that hydroxyl radicals are generated also in the absence of UV light. It has been shown that fish cells are generally more susceptible to toxic/oxidative injury than mammalian cells.

However, it can cause photosensitivity, which is why it’s often combined with silica or alumina to prevent cell damage.

Lithopone, C.I. Pigment White 5, is a mixture of inorganic compounds, widely used as a white pigment powder. It is composed of a mixture of barium sulfate and zinc sulfide. These insoluble compounds blend well with organic compounds and confer opacity. It was made popular by the cheap production costs, greater coverage. Related white pigments include titanium dioxide, zinc oxide (zinc white), zinc sulfide, and white lead.^[1]

Typically, this mineral is produced in two forms. The primary type is pigment-grade titanium dioxide, which utilizes its pigment to provide a look of sensitivity and brightness.