I was reading this about polystyrene, which says: "Polystyrene is an odorless, tasteless, rigid thermoplastic", and got hung up on "tasteless".
I searched Chemistry.SE for "tasteless" and found this and this, but they don't exactly answer my question in the title, because polystyrene is not considered a poison and is not a natural compound. So for such a highly-used, man-made, industrial-scale-manufactured compound, how do we know its taste (or lack of it)? Was the data acquired in an official way, through intended testing, or only from "accidents" (which I cannot imagine, so just for the sake of argument)?