In its 2016 opinion, the ANS Panel recommended new studies be carried out to fill the gaps on possible effects on the reproductive system, which could enable them to set an Acceptable Daily Intake (ADI ). Uncertainty around the characterisation of the material used as the food additive (E 171) was also highlighted, in particular with respect to particle size and particle size distribution of titanium dioxide used as E 171.   

The Scientific Committee on Consumer Safety issued an opinion of the safety of titanium dioxide in food, stating that it should no longer be considered as safe when used as a food additive.

Conclusion

In a study published in 2022 in the journal Particle and Fibre Technology, researchers examined the impact of maternal exposure to titanium dioxide nanoparticles in newborn offspring mice. They found that “a chronic exposure to TiO2 NPs during pregnancy alters the respiratory activity of offspring, characterized by an abnormally elevated rate of breathing.” Breathing was also shown to be “significantly and abnormally accelerated,” and the ability for neural circuitry to effectively adjust breathing rates was impaired. The researchers concluded: “Our findings thus demonstrate that a maternal exposure to TiO2 NPs during pregnancy affects the normal development and operation of the respiratory centers in progeny.”