The vitaminC@P25TiO₂NPs, on the other side, did not have any effect on cell protection against ROS. This might be due to the fact that vitamin C, a well-known scavenger of ROS, could behave as prooxidant and even promote ROS and lipid peroxidation [39]. It was recently described that at small concentrations of vitamin C, the prooxidant effects dominate; while in large concentrations the antioxidant ones predominate [40]. The effect also depends on the cell state and the interaction of vitamin C with light. In this case, ascorbic acid may act as an antenna to harvest visible light when conjugated to P25TiO₂NPs. Indeed, it was previously found that this combination (in some ratios) could have an improved photocatalytic activity, possibly due to a red shift in its light absorbance [41]. Further studies on vitaminC@P25TiO₂NPs were not conducted, because of the poor antioxidant capacity [42].

Matthew Wright, chair of the authority's working group on titanium dioxide, noted that the evidence for general toxic effects was not conclusive, but that the panel couldn't rule out genotoxicity entirely. There were also some current data limitations and the assessment could not establish a safe level for daily intake of the food additive, he stated.

What is titanium dioxide? Why is it used in food products?

The European Commission banned titanium dioxide as a food additive in the EU in 2022 after the European Food Safety Authority (EFSA) conducted an updated safety assessment of E171 and concluded the panel could not eliminate concerns about its genotoxicity. 

Synthesis of vitaminB2@P25TiO₂NPs

Anatase titanium dioxide is a popular ingredient in coatings due to its excellent UV resistance and chemical stability. Many manufacturers and businesses rely on wholesale suppliers to provide high-quality anatase titanium dioxide for their coating applications.

Titanium dioxide (TiO2) is a naturally occurring compound that is mined, refined and processed into a fine powder. It is known for its exceptional opacity, brightness and high refractive index, making it an ideal ingredient in paint formulations. When added to paint, titanium dioxide scatters and reflects light, creating vibrant, long-lasting colors. It is this unique property that makes titanium dioxide the most widely used white pigment in the coatings industry.

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.  

What are the different forms of titanium dioxide in beauty and personal care products?

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.

Because of health risks, France banned titanium dioxide as a food additive in 2020. Two years later the European Union also banned titanium dioxide as a food additive. 

Titanium dioxide (TiO₂). Titanium dioxide is the most common white pigment used today. As a pigment, titanium dioxide is unique because it combines both high colouring and high opacifying capacity. This is mainly due to its high refractive index (2.7). Furthermore, titanium dioxide is an excellent UV absorber (it is used in sun protective creams). Some typical properties are: density 3.3-4.25 g/cm³; pH of water suspension 3.5-10.5; particle size 8–300 nm; oil absorption 10–45 g/100 g; specific surface area 7–160 m²/g. Most titanium dioxide is produced from the rutile (TiO₂) or ilmenite (titanate of ferrous iron). Titanium dioxide can be obtained using different processes.

It doesn’t take much to imagine what they must be doing to our poor skin each day as we layer on our sunscreen, foundation, concealers, eyeshadows & lip sticks which all contain large doses of titanium dioxide.

2C+O2→2CO2

Lithopone

In 2022, a year after the EFSA recommended against the use of E171, the Food Standards Australia New Zealand (FSANZ) conducted its own reassessment of titanium dioxide as a food additive. The agency concluded that titanium dioxide was indeed safe to use as a food additive. The United Kingdom and Canada came to similar conclusions.

1. Enhanced Durability and Performance One of the critical benefits of incorporating titanium dioxide into tire formulations is its ability to improve overall durability. Tires containing TiO2 exhibit increased resistance to wear and tear, which is essential for vehicle performance and safety. Additionally, TiO2 contributes to reduced rolling resistance, which can enhance fuel efficiency in vehicles.

Below are selected applications of photocatalytic pollutant decomposition processes on titanium oxide:
1. Self-cleaning surfaces: for the production of glass for spotlights, traffic lights, car mirrors, window panes, for road paints, for covering sound-absorbing screens and tunnel walls.
2. Air cleaning and odor removal: filters that are used in enclosed spaces (e.g. public toilets) or filters for air-conditioning equipment.
3. Water treatment: groundwater treatment installations, water purification installations in the intakes of drinking water from rivers.
4. Self-disinfecting materials: towels, linings, clothing, equipment in hospitals, wall surfaces of operating rooms.
5. Removal of lesions: anti-cancer therapy.