Cinnamon Leaf is high in a component called Eugenol, a Phenol. Phenols are considered to be the most irritating components to the skin and mucous membranes and can cause dermatitis and sensitization. If phenols are present in high concentrations in an essential oil, that oil should be used in very low dilutions on the skin (0.5% or less in a carrier) and for short periods of time. They are generally not safe for the skin in a bath. Use caution if diffusing or using in an inhaler. Phenols high oils are not used with babies and children. Not to be used neat (undiluted) on the skin. Robert Tisserand, in his book Essential Oil Safety, states that oils high in eugenol should be used with caution on those with impaired liver function.Do not use Eugenol high oils (like Cinnamon Leaf, Clove Bud & Tulsi) with people who have clotting disorders, as eugenol is an anticoagulant.
Always dilute essential oils with a carrier oil.