A few non-dietary studies have reported adverse effects in the gastrointestinal tract of laboratory animals given food-grade TiO₂. However, these same effects were not seen when the same or higher doses of food-grade TiO₂ were administered in the animals' diet. Dietary studies best reflect how humans are exposed to TiO₂ from food. Thus, the Food Directorate placed the most emphasis on the results of these studies in the state of the science report.

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.