The Rabbinical Assembly, which represents Conservative rabbis, has endorsed the idea of a hechsher tzedek ("certificate of justice"), a Jewish seal of approval that would go beyond the usual dietary rules to include the compensation and working conditions of people who produce kosher food. It's the brainchild of Minnesota rabbi Morris Allen, who was upset by reports that immigrant workers at a kosher slaughterhouse in Iowa are poorly paid, receive meager health benefits, and get inadequate safety training. Not surprisingly, Orthodox rabbis, who have long dominated the business of certifying food as kosher, are not pleased with Morris' idea.
Although some of Morris' critics may have a vested interest in resisting competition, they do have a point: The question of whether food was "justly produced," unlike the question of whether it's kosher, is not a uniquely Jewish issue, and it is open to a lot more interpretation and argument. I doubt that imponderables such as what constitutes a "just" wage, "just" fringe benefits, and "just" hours can be resolved even by the most conscientious application of Jewish law.
I assume the hechsher tzedek would not be arbitrarily limited to meat, that it would apply to all kosher food, including processed foods, in which case the certifying authority presumably would have to investigate not just one factory for any given product but all the factories that make the ingredients used in that product. For that matter, why limit the hechsher tzedek to food? Shouldn't Jews also be concerned about how their sneakers and T-shirts are produced, for instance? No doubt some Jews also would demand that the criteria for a just product include factors such as environmental sensitivity and local production. Then the hechsher tezedek would start to poach on "organic" territory.
To convince manufacturers that the hechsher tzedek is worth paying for, I think its advocates would have to demonstrate a market wider than the subset of observant Jews who make purchase decisions based on how well a manufacturer treats its workers. I'm sure there are a lot of non-Jews who are interested in the subject. But that raises the question of what makes this a specifically Jewish project to begin with.