I just heard about something similar to my smart phone application that rates products holistically for health and sustainability already exists. It is called GoodGuide.
GoodGuide rates all sorts of food and household items based on research in a number of factors. Products are rated on categories of health, environment and society and then given a final score out of ten. They provide data on the company's environmental practices, human rights standards, how they treat their employees, ethical principles, the health of the product and more. What i like is the variety of information and how they present it all in one easy to understand package.
I downloaded the iphone app and started scanning everything in my cupboard. Even in Canada, buying mostly off-brand, a few things were in their database. Quite a helpful tool.