Biodegradable packing peanuts are edible and digestible. However, they have no nutritional value and are not manufactured under food-safe conditions. The manufacturers of the peanuts generally advise against eating them. They are made out of starches derived from various grains, chiefly corn.
Chef Homaru Cantu used biodegradable packing peanuts in a dish on the TV show "The Iron Chef" in 2006. The chef explained they were edible and could be flavored to taste like anything, such as the crème brûlée he used on the show.
Biodegradable packing peanuts readily dissolve in water and can be washed down the drain. They can also be composted. Rodents do not eat them.