We've measured many different immunological markers, both in the mucosa of the intestine and the lymphoid organs part of the intestine and we didn't see any inflammation there or changes in white blood cell number, Kaminski said. They also looked at the spleen where titanium dioxide was taken up into the bloodstream. You would expect [titanium dioxide] would be filtered out in the spleen and maybe induce inflammation there, but we did not see that, Kaminski added.
Titanium dioxide as used in sunscreens is commonly modified with other ingredients to ensure efficacy and stability. Examples of what are known as surface modifier ingredients used for titanium dioxide include stearic acid, isostearic acid, polyhydroxystearic acid, and dimethicone/methicone copolymer.
For years scientists have raised concerns about the potential toxicity of titanium dioxide.