Anything is toxic if you take it in huge amounts, even water!
The amount of an essential oil you would need to be considered toxic, is measured in liters. There are differing amounts for different oils.
Essential oils are usually sold in bottles around the 15ml size. There is no danger of overdosing on this amount. I cannot vouch for the intensity of diarrhea or vomiting you may experience, though!
Posted in: Essential oil safety