I'm always amazed at the number of consumer items that are labeled "do not eat". Things like packets of silica gel or Silly Putty (which is probably edible).
Years back a guy had an idea to vacuum dropped popcorn from movie theaters, bag it, and sell it as packing material. It would remain in small plastic bags when used as packaging.
The FDA said that, for him to do so, he would need to paint the popcorn black so that people would know not to eat it. I don't think the FDA considered that people might think it was licorice flavored popcorn, much like brown popcorn is caramel flavored. Nevertheless, the cost of painting the popcorn made the idea too expensive.