The Sydney Morning Herald reported on the finding of nano particles in our food supply here in Australia, despite no testing every carried out on the safety of these products by our food safety body.

Zinc Oxide

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.

Likewise, the plastics industry relies heavily on titanium dioxide to enhance the appearance and durability of plastic products. With the increasing popularity of plastic packaging and consumer goods, the demand for titanium dioxide in this industry is expected to witness steady growth in the coming years. The versatility of titanium dioxide makes it a valuable additive to improve the brightness, opacity and color stability of plastic materials, ensuring improved product performance and consumer satisfaction.

Lithopone is produced by coprecipitation of barium sulfate and zinc sulfide. Most commonly coprecipitation is effected by combining equimolar amounts of zinc sulfate and barium sulfide:

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