Polyquaternium-10
Polyquaternium-10
Cellulose-derived conditioner in shampoos.

How solid is the pore-clogging number
Polyquaternium-10 rates 1 of 5 — unlikely to clog pores for most people. The rating is graded moderate. Reasonably supported, but from fewer or less direct sources than the best-established ratings.
It describes the raw ingredient in isolation. In a finished product, how much is present and where it sits in the list matter just as much. Check a whole label to see it in context.