The idea is certainly good, but there’s a lot of bookkeeping that will need be done within the myriad supply chains that create the products, that isn’t getting done now. Does California have enough clout to force it to be done? Seems unlikely (even if we are the Nth largest economy on earth, where N is small). Really we need to partner with the EU, and other like-minded bodies to come up with a single standard we can all adhere to. This is the kind of thing the WTO should (for instance) be about.