Plans for a huge and controversial new chemical plant in Antwerp, Belgium, are drawing attention to several European countries’ growing imports of chemicals from the United States: by-products of fracked natural gas and oil that would fuel plastic production, even as the European Union rolls out aggressive plans for reducing plastic waste and battling climate change.

The U.S.-to-Europe trade in petrochemical by-products, coming as global demand for plastic climbs, could potentially undermine the European goals on both waste and carbon emissions.

The expansion of hydraulic fracturing, or fracking, in the United States has created a plentiful supply of ethane, an ingredient for making plastic which flows as a by-product of fracking for oil and