I use polyurethane on most of the things I build including a dining room table made of cherry.
I have never worried about "food safe" as we use plates and silverware to eat with and seldom lick food off the table. (Although I'm sure my grandkids probably have.
)
My understanding is that most, if not all finishes sold in the United States of America is food safe once it is cured. How long the "curing" time is up for debate but, I would think that 30 days is WAY MORE than adequate and is probably overkill.
I also think that the amount of finish ingested would have to range of a ounce or so to cause any serious health issues and eating glue or chewing on a wooden pencil or eraser would be far more dangerous to a child's health. (Know anyone who has ever done that? Did it cause brain damage or death? Other than choking on it I mean.)
There is far too much concern on paint and finishes as far as I'm concerned. Lead paint was outlawed several years ago. To be honest, when I was a baby, I'm sure my baby bed was painted with lead paint and I'm equally sure I chewed on it when I was cutting teeth.
NO! I'm not going to ask if you think it affected me, so just keep your comments to yourself!
Rog
PS I've lived to be 70 years old so far.