First MAS Vendor Meets NSF Protocol for Sustainable Services Submitted by Elizabeth Skolnik on Wednesday, March 6, 2013 - 2:11 PM GSA is pleased to announce that MAS Vendor, Marstel-Day, has become the first certified environmental management company through the protocol NSF P391: 111Tags: sustainabilitygreenServicesMASgreen servicesNSFprotocolstandard Views: 1783