ABSTRACT
According to the chemical denition, an essential oil (EO) is a concentrated hydrophobic liquid containing volatile aromatic compounds from plants and is characterized by its volatile properties; this last characteristic justies other terms used to dene EO, such as volatile oil, ethereal oil, aetherolea, or simply “oil of” the plant from which it was extracted, for example, eucalyptus oil and rose oil. Among the herbal materials, according to the denition of the World Health Organization (WHO), the essential oils are “the scented liquid taken from certain plants using steam or pressure. Essential oils contain the natural chemicals that give the plant its ‘essence’ (specic odour and avour). Essential oils are used in perfumes, food avourings, medicine, and aromatherapy.”
