I'm excited about answering this question because I recently discovered a systematic and easy way for homeowners to get this kind of information from vendors.
The U.S. Green Building Council (USGBC) and the American Society of Interior Designers (ASID) in 2008 partnered in the development of a set of green "best practice" guidelines called the Regreen Program. One of the features of the program is a Green Product Checklist, available as a free download, that has all the questions you would never think of asking about what makes a product green. The checklist covers manufacturer commitment to sustainability, product composition, VOC emissions, product lifecycle (whether the product is durable, biodegradable, and/or recyclable), and so on.
The Green Product Checklist is a wonderful resource that I give to everyone to distribute to their vendors and suppliers when applying green strategies in any type of construction. Not all the questions need to be answered or are applicable to every project. But if a vendor/installer hesitates about completing the checklist, it's a red flag. You do not have to apologize for having vendors fill out the checklist. You are only asking them to help educate you about what they are selling or installing. You can then compare the completed checklists of different vendors that you are seeking bids from.
The Regreen Program is not a formal certification process, and it does not endorse any specific products or brands. But the website is an excellent resource in language that is easy to understand. In addition to the Green Product Checklist, the site also includes green remodeling project case studies and home renovation webinars.