Saginaw, Mich. — Duro-Last has achieved platinum certification under the NSF American National Standard for Sustainable Roofing Membranes – NSF/ANSI 347. Certified by UL, this standard represents that Duro-Last manufactures a product that is third-party verified as sustainable, durable and high performing. The certification applies to 40, 50 and 60 mil, white, tan, gray and dark gray as well as 50 mil terra cotta Duro-Last membranes.