Assess what the product is packaged with, and how it's transported to the point of purchase. Also confirm whether or not it'll release VOCs [1] (volatile organic compounds) during and after installation, how much energy it uses, and maintenance requirements.
Links:
[1] http://www.moneypit.com/question-and-answer/low-voc-paint-earth-and-human-friendly-paints-provide-great-project-results