≤0.3

In addition to controlling the reaction conditions, it is also important to carefully monitor the precipitation process to ensure that the desired precipitation percentage is achieved. This can be done through various analytical techniques, such as X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy, which can provide valuable insights into the particle size distribution, crystallinity, and purity of the titanium dioxide product.

Lithopone is rather nontoxic, due to the insolubility of its components. It has been used in medicine as a radiocontrast agent. Lithopone is allowed to be in contact with foodstuffs in the US and Europe.

Nowadays, the use of nanoparticles in pharmaceutical and cosmetic products has increased. In the last case, nano-sized components are used without proper characterization of their effects, leading to unwanted and dangerous consequences for the users [1,2].

Skin-penetration studies 

Titanium dioxide is a white food coloring agent often used in bakery decorations, soups, broths, sauces, spreads, creamers, candy, and chewing gum.

As mentioned above, these oxide NPs are harmful in part because both anatase and rutile forms are semiconductors and produce ROS. Particularly, P25 kind has band-gap energies estimated of 3.2 and 3.0 eV, equivalent to radiation wavelengths of approximately 388 and 414 nm, respectively. Irradiation at these wavelengths or below produces a separation of charge, resulting in a hole in the valence band and a free electron in the conduction band, due to the electron movement from the valence to conduction bands. These hole–electron pairs generate ROS when they interact with H₂O or O₂ [43,44]. It was described that they can cause an increase in ROS levels after exposure to UV-visible light [45]. The NBT assay in the studied samples showed that bare P25TiO₂NPs produce a large amount of ROS, which is drastically reduced by functionalization with vitamin B2 (Fig. 5). This vitamin, also known as riboflavin, was discovered in 1872 as a yellow fluorescent pigment, [46] but its function as an essential vitamin for humans was established more than sixty years later, and its antioxidant capacity was not studied until the end of the XX century [47,48]. This antioxidant role in cells is partially explained because the glutathione reductase enzyme (GR) requires it for good functionality. This enzyme is the one in charge of the conversion of oxidized glutathione to its reduced form which acts as a powerful inner antioxidant and can quench the ROS [49,50]. The cost of this action is that the glutathione is converted to the oxidized form and needs to be recovered by the GR. Consequently, the cells need more vitamin B2. Another glutathione action is the protection against hydroperoxide. This activity is also mediated by riboflavin. Therefore, local delivery of this vitamin seems to significantly help the cells in their fight to keep the oxidative balance, once they are exposed to high levels of ROS.

Titanium dioxide is used a food colour (E171) and, as with all food colours, its technological function is to make food more visually appealing, to give colour to food that would otherwise be colourless, or to restore the original appearance of food. Titanium dioxide is also present in cosmetics, paints, and medicines.

According to the manufacturer feedback, mainstream factory new single pretty price, clinch a deal market as a whole center of gravity move up. Demand side, currently has consider autumn with cargo terminal and actual transaction will increase; The supply side, the mainstream manufacturers, there are some load increase, industry actual output increased slightly. Part of the plastic and paper related downstream feedback tight type price for some goods is higher. Recent titanium pigment raw material prices strong, titanium white price support also increases, the comprehensive market all factors, the current market to maintain a valence state of titanium white.

The FDA and certain others say titanium dioxide is safe to use in foods and personal care products. The FDA provides strict guidelines on how much can be used in food. The limit is very small: no more than 1% titanium dioxide.

Titanium dioxide, or TiO2, sometimes referred to as E171, is an inorganic, solid substance used in a wide range of consumer goods including cosmetics, paint, plastic and food, according to the American Chemistry Council.

Nano-sized TiO₂ generally shows low or no acute toxicity in both invertebrates and vertebrates. However, exposure of Daphnia magna to 20 ppm TiO₂ for 8 consecutive days was found to cause 40 % mortality. Zhu et al. showed minimal toxicity to D. magna after 48 h exposure, while upon chronic exposure for 21 days, D. magna suffered severe growth retardation and mortality. A significant amount of nano-sized TiO₂ was found also accumulated in the body of the animals. Similar findings with coated nano-sized TiO₂ (T-Lite™ SF, T-Lite™ SF-S and T-Lite™ MAX; BASF SE) were reported by Wiench et al. Biochemical measurements showed that exposure to TiO₂ NPs induces significant concentration-dependent antioxidant enzyme activities in D. magna. Lee et al. showed that 7 and 20 nm-sized TiO₂ induced no genotoxic effect in D. magna and in the larva of the aquatic midge Chironomus riparius.

Certificate of Analysis (Lithopone B301, Lithopone B311 powder TDS)

Fig. 9. Selected images of damaged skin treated with P25TiO₂NPs 10% (left) and healthy skin treated with VitaminB2@P25TiO₂NPs 10% (right).