There is some evidence that ingested titanium dioxide does not completely exit the body. A 2015 review of animal studies and a few human studies suggests titanium dioxide can get absorbed into the bloodstream and expose other organs to damage.

Our scientific experts applied for the first time the 2018 EFSA Scientific Committee Guidance on Nanotechnology to the safety assessment of food additives. Titanium dioxide E 171 contains at most 50% of particles in the nano range (i.e. less than 100 nanometres) to which consumers may be exposed.