Generally, it is the essential oil of perilla that is considered toxic as it contains high amounts of ketones. High amounts of ketones in the blood can cause shortness of breath. One would have to eat a lot of perilla (several pounds in one sitting) in order to ingest the toxic amount. Just as oil of peppermint contains high levels of menthol, which can be toxic when taken in high enough doses, but is safe when used properly.

It is guite hard to plant only non toxis plants, even edible plants like tomatoes have edible fruit but toxic leaves.

For absolute safety, teach your children to never eat any leaf, fruit, berry or seed without your permission. Read them some fairy tales that featured poison fruit (like Snow White or Sleeping Beauty), and tell some tales about children who had to get their stomach pumped to get the message across.

Thank you both so very much for your help.

Nwl_me, this is exactly the information that I needed
to make some informed decisions about
plants that might be included in a public access garden next year.
So long as children would not be endangered just by touching the plants
and then putting their hands into their eyes or mouths,
or even by the occasional nibbling of a leaf, I will feel okay about using it.

Great advise, Judy, and I think I will suggest installing some signs to that effect,
as a reminder to older children, and the supervisors of the younger ones.
A good teaching opportunity ;^)

The roots are very poisonous. Used as a rat poison.

Rain1950, I've grown perilla for many years and I've never heard of the roots being toxic, other than when they extract the essential oil from the whole plant including the roots.

Decompost, you might want to check up on it.