There's a lot grey area when it comes to claiming a product is environmentally friendly. We are only recommending products from reputable companies but sometimes a term like biodegradable has a specific meaning. It might be biodegradable under certain circumstances and not others. We don't all have the time to be material scientists and investigate every claim.
Even without getting into the specifics of how marketing copy comes to be it's worth being careful. If a product effectively strips the gunk off a dirty chain, it's probably a good idea to treat it with some caution. That means considering how it's disposed of and thinking about what is being washed away along with the cleaner. Just because a company is environmentally conscious and the cleaner is technically safe doesn't mean you should wash your bike in your vegetable bed.