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 risks associated with titanium dioxide exposure depend on a variety of factors, including the form of the mineral, the route of exposure (such as being inhaled or consumed), and the duration and intensity of exposure.