Lithopone was discovered in the 1870s by DuPont. It was manufactured by Krebs Pigments and Chemical Company and other companies. The material came in different seals, which varied in the content of zinc sulfide. Gold seal and Bronze seals contain 40-50% zinc sulfide, offering more hiding power and strength. Although its popularity peaked around 1920, approximately 223,352 tons were produced in 1990. It is mainly used in paints, putty, and in plastics.

Safety[edit]

You may be taking a second look at your favorite candy after hearing this week's news about titanium dioxide. Recently, a lawsuit was filed against Mars, Inc. based on claims that the manufacturer's popular Skittles candy is unfit for human consumption. The class-action lawsuit, filed in U.S. District Court for the Northern District of California in mid-July, alleged that the candy contained heightened levels of a known toxin called titanium dioxide — a food additive that the company previously pledged to phase out from their products in 2016, according to the Center for Food Safety.

One of the key responsibilities of titanium dioxide manufacturers is to produce high-quality products that meet the stringent requirements of their customers. This involves carefully sourcing raw materials, employing efficient production processes, and conducting rigorous quality control measures to ensure that the final product meets the necessary specifications.

Calcium carbonate is a naturally occurring mineral that is found in rocks and minerals such as calcite, aragonite, and limestone. It is commonly used in industries such as paint, paper, plastics, and rubber as a filler and pigment. The manufacturing process of calcium carbonate involves extracting the mineral from quarries or mines, crushing and grinding it into a fine powder, and then purifying it through various chemical processes.

The toxicity of P25TiO₂NPs was evaluated in both prokaryotic (Fig. 3) and eukaryotic cells (Fig. 4). The XTT assay was chosen to measure the cell viability in bacterial cultures of MSSA, a normal skin microbiota microorganism. The reduction in the viability of samples with bare NPs is notorious, possibly due to the described ROS production from the interaction of P25TiO₂NPs with light [37]. This effect seems to be avoided when they are functionalized with vitamin B2. Also, the most concentrated vitaminB2@P25TiO₂NPs sample (0.2 mg/mL) shows up to 60% more absorbance after 6 h compared to the bare NPs (due to normal cell replication). This may indicate that the antioxidant effect of the vitamin B2 coating is greater than the oxidation damage produced by the NPs. This protective capacity could be attributed to the glutathione redox cycle and the conversion of reduced riboflavin to its oxidized form [38]. Values of cell viability greater than 100% are not rare and could be understood because the XTT assay actually measure metabolic activity when reducing the tetrazole to formazan. It is usually assumed that conversion is dependent on the number of viable cells, but it could also be related to an expected increased enzymatic activity when cells are exposed to small doses of some new substance. Further analysis showed that this effect was not the only one responsible for better cell viability of vitaminB@P25TiO₂NPs treated samples.