What is Titanium Dioxide?
Chemically, Titanium Dioxide is a mineral-based ingredient. A mineral sunscreen and white pigment generally regarded as low-risk (around 1) and non-comedogenic.
You may see it on labels as Titanium Dioxide, Ci 77891, so it can hide under more than one name in an ingredient list.
Where Titanium Dioxide shows up
Titanium Dioxide is commonly formulated into sunscreens, mineral makeup, and masks. Separately from clogging, its irritancy is rated 0/5 — low, so it's unlikely to sting or sensitise on its own.
Is Titanium Dioxide bad for acne-prone skin?
That low score makes Titanium Dioxide a reasonable choice even for acne-prone skin. As always, individual reactions vary, but it is not a likely cause of clogged pores.