The San Francisco Chronicle has a resource of an article timed for Earth Day that goes behind the scenes behind the green seal certifications you see on many products today. I've chatted in the past about "greenwashing" a product and this article explains the limits of our current regulations. For instance the word natural is basically meaningless, meaning coming from natural ingredients. TerraCycle performed some analysis that revealed that only a minority of claims down and out lie, the vast majority play fast and loose.
Regulated standards are nice, but given enforcement is sketchy and haphazard even that won't fix the problem. The best solution is to ask what are the motives of the seller? Is it a public company, than your first response should be "uh oh". I don't mean to say that all public companies are bad or deceitful, but the forces at play make it very difficult since their stock and performance will be measured against their peers, and unless all pursue the same path, the pressure to relent is just too great.
Secondly, look at the composition of the product? Is it synthetic, can you recognize the materials in the product. That's the Michael Pollan solution. The other thing is look at what the company does, if they are pro-environment. They are probably pro-good causes with other aspects including hiring, compensation and health benefits.