December 17, 2004 - Berkeley, Calif., Adopts Green Purchasing Policies

FYI...the link below provides an interesting article outlining some of Berkeley California's positive results from their comprehensive 'Green' Purchasing Policies.
Note that unlike others, the City did IMPLEMENT an encompassing 'Green' Program, including cleaning chemicals, and they did get the job done. They did more than 'talk the talk'.
A particular finding that you should note is their experience by going to 'green' cleaning chemicals proved there were no additional costs, and in some cases, costs were reduced.
At the bottom of the article, 'More News', will provide other interesting articles.

http://www.greenbiz.com