MONACA, Pa. — Economic “game changer” is not a phrase often used in Appalachia and rarely a phrase proclaimed in unison by politicians from both parties at the same time on any subject. Yet since 2016, when Shell Chemical announced it was building a $6 billion ethane cracker plant here, an economic revolution began that is far from reaching its potential.

Mention “cracker plant” in most parts of the country and people think you are making a Nabisco product, but the cracker plant in Beaver County is all about a molecular “cracking,” in which extreme heat “cracks” ethane molecules to form new ones that will eventually produce more than a million metric tons of polyethylene, a type of plastic used in all kinds of common household products.