Background

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.

Now if your an Aussie, I am sure you have seen the Bluescope Steel add about how it stands up to the test of time & the elements – but a little bit of titanium dioxide & it’s all over!!!

Declaration of Competing Interest

Drobne et al. used the terrestrial arthropod Porcellio scaber as a test organism for determining the cytotoxic effect of TiO₂ NPs (anatase). The animals were exposed to TiO₂ NPs of two different sizes (25 nm and 75 nm) in the concentration range 10–1000 μg TiO₂/g dry food for 3 to 14 days. No adverse effects, such as mortality, body weight changes or reduced feeding, were observed. In fact, quite the opposite, an enhanced feeding rate, food absorption efficiency and increase in catalase activity were observed. The intensity of these responses appeared to be time- but not dose-dependent. It should also be noted that the concentrations tested in this study were much higher than the predicted concentration (4.8 μg/g soil) at high emission scenario of nano-sized TiO₂. Using the same test organism another group showed that exposure to TiO₂ NPs induced destabilization of cell membrane in the epithelium of digestive glands isolated from exposed animals. They also showed that this effect can be observed after just 30 minutes of exposure.

As a food additive, titanium dioxide and its nanoparticles in particular have been associated with DNA damage and cell mutations, which in turn, have potential to cause cancer. When used as a food coloring, it is known as E171.