Workers at DuPont's Marshall Laboratory at 3400 Grays Ferry Avenue were told that the plant will close at the end of June, according to sources.
The closure affects 265 employees who would be without a job.
DuPont's corporate offices didn't verify the amount of Philly layoffs. DuPont did confirm that about 2,000 jobs were cut globally as part of the company's restructuring plan.
Earlier this year DuPont announced that they would make moves to remain competitive in the global economy despite falling sales.