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. 

Stability and darkening[edit]

Neutral White, 26 per cent zinc sulphide, 66 per cent barium sulphate, 5 per cent infusorial earth, 3 per cent whiting.

Infrared analysis showed that the characteristics bands for the bare nanoparticles are still exhibited in the vitamins@P25TiO₂NPs spectra, such as a wide peak in 450–1028 cm⁻¹ related to the stretching vibration of Ti-O-Ti and other peaks in 1630 cm⁻¹ and 3400 cm⁻¹, which represent the surface OH groups stretching. The IR spectrum of vitaminB2@P25TiO₂NPs showed signs of binding between compounds. The OH bending peak (1634 cm⁻¹) corresponding to bare nanoparticles disappeared, and the NH₂ bending band characteristic of vitamin B2 appeared (1650 cm⁻¹). The IR spectrum of vitaminC@P25TiO₂NPs also showed signs of successful functionalization. Bands at 1075 cm⁻¹; 1120 cm⁻¹; 1141 cm⁻¹ were observed, which are originated by CO-C vibrations present in the vitamin C. The intense band at 1672 cm⁻¹ is attributed to the C = O stretching in the lactone ring while the peak at 1026 cm⁻¹ is ascribed to the stretching vibration Ti-O-C. Wide bands at 3880–3600 cm⁻¹ are related to stretching vibration OH groups, but those disappear in the modified nanoparticles spectrum. These observations confirm the interactions between the P25TiO₂NPs and the vitamins [35].

To overcome this challenge, manufacturers use advanced technology and processes to monitor and control the buff percentage of their products. This may involve the use of sophisticated equipment to measure the coating thickness of titanium dioxide particles, as well as automated systems to adjust the level of coating as needed. By carefully controlling the buff percentage, manufacturers can ensure that their products meet the specifications of their customers and maintain a high level of quality and performance.

On the other hand, Westerhoff said, there are hundreds of studies showing no adverse effects from the substance.

The EU expert panel did not identify an immediate health concern linked to TiO₂ when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO₂ nanoparticles, the panel concluded that TiO₂ as a food additive (E171) could no longer be considered safe.