The dishonest practice of intentionally increasing the quantity of an essential oil by adding synthetic chemicals, cheaper substitute oils, or fractions of other distilled products. Adulteration causes dilution of the original pure oil with a corresponding decrease in its quality or, worse, the addition of potentially toxic components. Inferior therapeutic benefit and/or fragrance results. The oil is rejected for production use since it does not meet industry standards for quality criteria.
Due to the high cost of many Essential Oils, the practice of adulteration is tempting for some manufacturers as an effort to either reduce their prices or increase their profits. It is impossible for a 1/2 oz of Jasmine to cost less than $10 unless it has been adulterated or diluted in some way. Melissa is another commonly adulterated oil.