A judge has been asked to force DuPont Co. to allow a science panel to study workers at a West Virginia plant where a chemical used to produce Teflon is the subject of a multistate health screening.

The health screening is part of a 2004 class action settlement of a lawsuit filed by West Virginia and Ohio residents over the contamination of their water supplies by the chemical ammonium perfluorooctaonate, also known as C8 or PFOA. The chemical is used by the company’s Washington Works plant near Parkersburg.