p–Xylene (para–xylene) is an aromatic hydrocarbon. It is one of the three isomers of dimethylbenzene known collectively as xylenes.
Paraxylene is widely used as a feedstock (or “building block”) to manufacture other industrial chemicals, notably terephthalic acid (TPA), purified terephthalic acid (PTA) and dimethyl-terephthalate (DMT). TPA, PTA and DMT are used to manufacture polyethylene terephthalate (PET) polyesters, a kind of plastic.