Buzzwords for Beginners

Adulterant - a substance, artificial or natural, added to an essential oil, which was not originally present in the oil at the oil at the time of distillation.

Base oil - (Carrier oil) vegetable or nuts oils, e.g., sweet almond, grape seed,jojoba; is used to dilute essential oils and absolutes before they are applied to the skin in massage and aromatherapy. They are so named because they carry essential oil into the skin.

Diffuser - a device that disperses essential oils into the area. The three basic types are clay, candle and electric.

Dilute - adding a small amount of essential oil to a larger amount of base oil to make it safe for use on the skin.

Distillation - method used to extract essential oil from the plant. Steam distillation is the most common form of distillation.

GC/MS (Gas Chromatography/Mass Spectrometry) - a device used by analytic chemists to determine the precise make-up of a given substance. Used in Aromatherapy to determine the precise  chemical constituents of an essential oil, and whether it is pure or adulterated with synthetic chemicals or other products.

Essential oil - highly aromatic substance found in specialized cells of certain plants. Technically, when this substance is in the plant, it is called an "essence". After distillation of a single type of plant, the aromatic substance is referred to as an essential oil. Essential oils may be used by plants for protection from predators, to attract pollinators or for other unknown uses.

Herbally infused oil - these are oils that carry the medicinal properties of certain herbs. A carrier oil is infused with the medicinal herb, the plant is strained off and the remaining oil can be used directly on the skin.

Neat - use of an undiluted essential oil on the skin.

Notes - as in top, middle and base notes. A type of classification system based on aroma, to identify certain oils.Generally, essential oils from citrus peels are top notes, essential oils from flowers, leaves and stems are middle notes and essential oils from roots are base notes.

Orifice reducer -  a device used to reduce the size of the opening of a bottle, making dispensing easier and more accurate.

Oxidation - when oxygen, light or heat interacts with essential oils, the essential oil begins to deteriorate over time. This can cause the essential oil to become skin irritating. It happens over the period of 1-3 years with oils high in monterpenes, phenols and oxides, and more slowly with the other chemical families.

Phototoxic - the use of the oil makes one's skin more prone to damage from the sun's UV rays. Primarily the citrus oils, especially Lemon and Bergamot, as well as Angelica oil, are phototoxic oils.


Volatile - describes how quickly a substance disperses itself into the air. In aromatherapy, top note essential oils may be referred to as "highly volatile", meaning that they disperse quickly out of the bottle an into the air.