Some food products will include titanium dioxide on their nutrition label. But again, it can be hard to tell for those who don't list the ingredient. 

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.   

When E171 is part of a food product, it passes through the digestive system without causing harm because E171 combines with the other ingredients.