Definitely diluted if for some reason you feel it necessary. Peppermint’s menthol can cause seizures.
I’m surprised I never found this out before and thankfully only had peppermint diffused/diluted for my 8 year old.
Over 6 is usually good and ratio should be still quite diluted.
A good alternative, spearmint. It does have some menthol but not as much. We just recently got the book :