Most mints are quite safe to handle, from the roots up. Pennyroyal is an exception - it can cause fits in certain sensitive people, including pregnant women (just by smelling it).

Mint leaves should not be given to very young children to eat - they don't usually chew properly and can gag or choke on unchewed leaves. That applies, of course, to anything they might eat!

Of course, any individual can be sensitive or allergic to anything, so just keep a careful watch on those kids. I would discourage children from eating any part of the plant but the leaves - a good object lesson in Safety First with Plants, and also, it's only the leaves and flowers of mint which are usually eaten.

Don't let them eat the leaves freely. Too much mint isn't good for anybody, much less children. But a nibble or a suck won't do any harm.

Thank you, Daisy. We're not eating the mint, just doing a simple activity with various plant parts. I needed some roots and thought mint might be ok. I usually use alyssum, but the alyssum I bought was not rooty enough so I thought I could supplement with mint.

You made a good decision. Alyssum is poisonous!!