After 3 years of age
Popcorn, nuts and similar items can be inhaled into babies lungs, go unnoticed for days, then trigger life threatening pneumonia
The item may have to be retreived thru a special scope in the operating room if you are lucky enough to figgure out what happened. They don't show up on xray. Until your child is old enough to talk and tell you this happened you are better off using something else.