Titanium Dioxide: E171 no longer considered safe when used as a food additive by European Food Safety Authority, May 6, 2021

EFSA Scientific Conclusion on E171

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.

5. Geographical Availability Depending on the location of businesses, suppliers with a good logistical network can ensure timely delivery and availability of stock. Local suppliers may also provide cost advantages compared to international counterparts due to reduced shipping fees.

5. Regulatory compliance The MSDS should also include information on regulatory requirements for the safe handling and use of lithopone, including any permits or certifications that may be necessary.

In a 2022 study published in the Journal of Hazardous Materials, scientists wanted to examine the effects of titanium dioxide as a food additive on atherosclerosis in mice. (Atherosclerosis refers to a hardening of the arteries.) Researchers fed mice 40 mg/kg of the food additive every day for 4 months, and found that it not only altered gut microbiota but also led to a significantly increased atherosclerotic lesion area, especially in animals that consumed a high-choline western diet (HCD).

Titanium dioxide manufacturer: CHTI

The analysis of the supernatant by UV–Vis spectrometry showed that each gram of P25TiO₂NP is loaded with 0.17 g of vitamin B2, after washing them. This value is coherent with the thermogram (Fig. 1), which showed a loss of 19% of weight, attributed to the thermal decomposition of vitamin B2.

Studies have been carried out with both emulsion paints and powder paints, both with clear results on how the use of Lithopone 30% reduces the appearance of algae in the paint once it has been applied (see photos). 

Colorectal tumors and preneoplastic lesions

In order to evaluate the penetration of the nanoparticles, eight adult male Wistar rats (3 months old) were used for the in vivo experiments. The protocol was approved by the local University Committee for animal testing and is in accordance with the Canadian Council on Animal Care (CICUAL-RD-2021–892-E-UNC-DEC#FCQ).