Inedible as in anything that isn’t food (ranging from something that would be dangerous, like glass, poisonous plants, or uranium, to something that is safe to eat but unpleasant with no nutritional value, like cardboard.) Eating the thing will be safe and painless.
Starch packing peanuts
You can already mostly safely eat those, it was one of my party tricks at my previous job. Don’t follow medical advice on the internet, ofc, myself included.
The starch ones are edible. Maybe the styrofoam peanuts?