Duan et al. administered 125 mg/kg BW or 250 mg/kg BW of anatase TiO₂ (5 nm) intragastrically to mice continuously for 30 days. The exposed mice lost body weight, whereas the relative liver, kidney, spleen and thymus weights increased. Particles seriously affected the haemostasis of the blood and the immune system. The decrease in the immune response could be the result of damage to the spleen, which is the largest immune organ in animals and plays an important role in the immune response. Powel et al. demonstrated that TiO₂ NPs may trigger immune reactions of the intestine after oral intake. They showed that TiO₂ NPs conjugated with bacterial lipopolysaccharide, but not TiO₂ NPs or lipopolysaccharide alone, trigger the immune response in human peripheral blood mononuclear cells and in isolated intestinal tissue. This indicates that TiO₂ NPs may be important mediators in overcoming normal gut-cell hyporesponsiveness to endogenous luminal molecules, which may be particularly relevant to patients with inflammatory bowel disease, which is characterized by an abnormal intestinal permeability.

In beauty and personal care products, the ingredient is listed with its colour index (CI) number ‘CI 77891’. When nano grade titanium dioxide is used in our sunscreens, this is referenced as ‘titanium dioxide’ [nano] in the ingredients list.

Titanium dioxide (TiO2) is used in a variety of personal care products, including sunscreens, pressed powders, and loose powders, as a UV filter or whitening agent. In lotions and creams (dermal exposure), it is not a risk for adverse health effects. However, when titanium dioxide is inhalable—as it may be when in powder form—it is considered a possible carcinogen by the International Agency for Research on Cancer.Titanium dioxide nanoparticles do not appear to confer any unique health hazards.

Molecular Weight: 412.207

In summary, the gravimetric determination of titanium dioxide is an invaluable technique in industrial applications. Offering precision and reliability, this method supports various sectors that rely on the quality and consistency of titanium dioxide in their products. By employing effective gravimetric analysis, manufacturers can enhance their operations and maintain competitiveness in a demanding market. As industries continue to evolve, the importance of accurate material analysis remains a cornerstone of successful production practices, ensuring that titanium dioxide remains a key player in future innovations.

Titanium dioxide comes in the form of a white powder and is sometimes used in cosmetics to adjust a color to a lighter shade. This is also why it can produce a white cast.

FDA’s response

Food safety experts in the European Union (EU) have recently updated their safety assessment of TiO₂ as a food additive. In Europe, TiO₂ is referred to as E171, in accordance with European labelling requirements for food additives. The EU expert panel took into account toxicity studies of TiO₂ nanoparticles, which to this point had not been considered relevant to the safety assessment of TiO₂ as a food additive.  

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.

Hemolysis was studied on suspensions of P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL), vitaminB2@P25TiO₂NPs (0.2 mg/mL and 0.02 mg/mL) and vitamin B2 (0.2 mg/mL and 0.02 mg/mL) were prepared and mixed with 500 μL of anticoagulated blood (donated by Laboratorio de Hemoderivados, UNC) in a rate of 1/10. A solution of NaCl 10% was used as the positive control and PBS as the negative control. Then, the samples were irradiated using the LED described above for 3 and 6 h to simulate the light penetration into the skin. Also, a set of samples was kept in the dark as control. Finally, the samples were centrifuged and the absorbance at 540 nm was measured in the supernatants. The experiment was reproduced twice; the standard deviation was calculated and p-value < 0.05 were considered significant.

Moreover, the gravimetric method's inherent accuracy makes it a preferred choice for regulatory compliance. Many manufacturing processes are subject to stringent quality regulations, and having reliable methods for determining material composition is fundamental to meeting these standards. Accurate gravimetric analysis assists manufacturers in minimizing waste, optimizing formulations, and ensuring that end products are both effective and safe.

In India, purchasers took a wait-and-see strategy because of the concerns about an unpredictable demand pattern following the second wave of the pandemic around the end of September. Whereas in China, producers were heard operating at optimal rates even though export orders were low in July.