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.
Our scientific experts applied for the first time the 2018 EFSA Scientific Committee Guidance on Nanotechnology to the safety assessment of food additives. Titanium dioxide E 171 contains at most 50% of particles in the nano range (i.e. less than 100 nanometres) to which consumers may be exposed.
Lithopone B301
On the other hand, some of the top manufacturers of titanium dioxide include Chemours, Tronox, and Kronos
. These companies have advanced chemical processing facilities that can produce high-quality titanium dioxide for various applications.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.