Essential oils are not cheap to make. Pure essential oils are expensive, labor intensive, and subject to all kinds of hard work. They are pricey, as any pure product, carefully grown and extracted should be. In order to make essential oils less costly, some companies will “extend” essential oils. That means, they will stretch them by diluting them in some way.
Oils can be adulterated in several ways during the production process, from diluting with cooking oils to adding synthetic chemicals. The important thing to know is that adulteration is always intentional—you cannot accidentally adulterate an oil.
This means that a naturally-occurring chemical constituent is added to the essential oil. One example is the chemical constituent alpha-pinene, a primary constituent in Frankincense. Alpha-pinene can be taken from trees used in the paper industry and added to Frankincense essential oil.
Adding Other Oils
Common essential oils can be added to rarer or more expensive oils. Cassia, for instance, is similar to Cinnamon oil, but much less expensive. It can be added to Cinnamon essential oil and not be easily detected because the aromas and chemistry are similar. The same can be done with Lemongrass and Melissa.
In order to make a small amount of essential oil larger, it can be diluted using carrier or cooking oils such as olive, coconut, or canola. This dilution lessens the potency and effectiveness of the oil.
Many of the chemical compounds found in essential oils can be synthesized in a lab. Typically, these synthetic constituents are created out of petro-chemicals. Lavender can be produced without using a Lavender plant at all, but by synthesizing linalool and linalyl acetate from petroleum-based products.
Extended with Alcohol
Another common way to extend an essential oil, and therein making it cheaper, is by adding alcohol to the EO. Ethyl Alcohol is a common substance added to EO to extend them. It’s very hard to detect this by smell, but it is possible.
In many cases, the added substance is inferior or even harmful. Adulterations not only have the potential to alter the chemical and physical properties of an oil, but they can decrease the efficacy of the oil, to produce an allergic reaction, irritation or toxic side effects.