What is Phenoxyethanol?
Chemically, Phenoxyethanol is a preservative. A broad-spectrum preservative rated 0/5 for clogging, mildly irritating for a few.
Where Phenoxyethanol shows up
Phenoxyethanol is commonly formulated into the tail end of almost any water-containing product. Separately from clogging, its irritancy is rated 1/5 — low, so it's unlikely to sting or sensitise on its own.
Is Phenoxyethanol bad for acne-prone skin?
That low score makes Phenoxyethanol a reasonable choice even for acne-prone skin. As always, individual reactions vary, but it is not a likely cause of clogged pores.