TiO₂ comes in many different forms. However, only a few of these forms are considered food-grade (acceptable to be added to food). Many studies that raised concern about the safety of TiO₂, including the concern for genotoxicity, used forms of TiO₂ that are not considered acceptable for use in food and have different properties than food-grade TiO₂. Other studies did use food-grade TiO₂, but took steps to break the material down into smaller particles than what would normally be found in food.

Nanoparticles

Here it has been shown that functionalization of P25TiO2NPs with vitamin B2 was able to significantly decrease the oxidative stress produced when they are exposed to sunlight. This finding is of main importance to prevent skin damage and toxicity of sunscreens containing this form of untreated titanium dioxide and should be taken into consideration when updating the regulations mentioned above .