In an effort to curb pollution from the seemingly ubiquitous white foam plastic coolers abandoned by careless boaters and river-floaters, the Missouri State Legislature inadvertanly banned  the wrong plastic - polypropylene - instead of expanded polystyrene.

The result can potentially land you up to a year in jail if you bring Aunt Millie's potato salad in a Tupperware bowl to a river picnic. The snafu also means that boaters and river-floaters who pollute the waterways with discarded EPS foam coolers can do so without fear of reprisal.

Apparently, show me the difference between PS an PP, was not  stated in the "Show Me State." Missouri Bans Wrong Plastic From Rivers