Essential oils are plant extracts, so many of use believe them to be totally safe. They can be dangerous if used improperly. The safest bet is to dilute them to their safest concentration. Sauce Ondulée uses essential oils for fragrance and antibacterial and antimicrobial purposes. They occur in the formulation at a combined concentration of 2% or less. #plantbased #cosmetics #safety #reaction #allergies #rosemary