Passing legislation without the latter is meaningless, and if you have the latter, you don't necessarily need legislation; the free market will force a correction (although politicians will follow the will of the people anyway).
You cannot achieve that across the countless toxins and/or potential toxins that exist in our world; the public does not have enough attention to spare for that.
Or to put it more simply, regular people don't have the time or energy to spare on worrying about every little thing that could potentially, maybe be toxic, in some tiny way over decades.
