Titanium dioxide particles help light scatter and reflect, Kelly Johnson-Arbor, MD, a medical toxicology physician at the National Capital Poison Center, told Health. Because of that, we often use it as a whitening agent.

The EU expert panel did not identify an immediate health concern linked to TiO₂ when used as a food additive. However, due mainly to uncertainties concerning the safety of TiO₂ nanoparticles, the panel concluded that TiO₂ as a food additive (E171) could no longer be considered safe.