What a 1/5 rating means
On the comedogenic scale, a 1 sits at the safe end of the scale — clogging is unlikely for most people. That places Titanium Dioxide in the range most people, including many with acne-prone skin, tolerate well.
One thing the number cannot tell you is concentration. Ingredients are listed in descending order, so Titanium Dioxide near the end of a label is present in tiny amounts and matters far less than the same ingredient near the top.
About Titanium Dioxide
It is a mineral-based ingredient, common in pigments and sun protection. A mineral sunscreen and white pigment generally regarded as low-risk (around 1) and non-comedogenic.
On a label it can read as Titanium Dioxide, Ci 77891 — worth knowing when you scan an ingredient deck.
Titanium Dioxide in makeup and skincare
It is central to mineral makeup, pressed powders, and mineral sunscreens. Its irritancy is rated separately at 0/5, which is low.