EPP or Environmentally Preferred Purchasing is a program started by the EPA to spur government purchases that helped green the federal government and its purchases. With its enormous buying power and the shear number of products and services needed by the federal government, this program now effects many vendors, contractors and even the everyday consumer.
This program helps purchasers find the green products and services that will help to create a more sustainable environment. While this isn't the only clearinghouse of such products, it is important to understand and oversee how our government is approaching green purchasing.
You can check it out for yourself at
http://www.epa.gov/epp/