Essential Oil Adulteration Part 3

Part 1 covers non-volatile adulteration and Part 2 covers adulteration with a similar (cheaper) essential oil. Both are worth a read, and we recommend you take a look if you haven’t already. In this part, we’ll be covering synthetic adulteration.

Type 3 is a synthetic chemical addition where petrol chemicals, such as fragrance components (which are cheap and readily available), are added to essential oils. Carbon-14 testing is a highly effective way to identify petroleum-based synthetic adulterations(1).

The idea of adulteration is to increase profits by replacing an expensive essential oil with a fake or to extend the expensive essential oil in a way in which customers will not readily recognize. Synthetic adulteration can be especially dangerous, causing adverse health effects. Using oils with these additives may produce short-term negative results depending on which chemical has been added, but long term, using them may lead to allergies, headaches, sensitivities, and/or toxicity. It simply doesn’t make sense to introduce harmful chemicals into the body at any point, much less in your essential oils you plan to use as a health aid.

Along with associated impurities and the synthetic chemical itself, another way these adulterants can have negative health consequences is the resulting incorrect enantiomeric distribution (molecules that are mirror images of each other). The therapeutic components of pure essential oils can and do vary one from another, but the same goes for enantiomers. For example, d-limonene can increase systolic blood pressure and alter alertness and restlessness whereas l-limonene only affects alertness(3). In this way synthetics can alter the overall way an oil affects the body, giving unintended, possibly harmful results.

The practice of adding a synthetic component to ‘convert’ one oil to another is another way synthetics could be used to deceive consumers. For example, a-terpineol and others can be added to Eucalyptus globulus to convert it to Eucalyptus radiata, and tangerine oil can be converted to mandarin oil through the addition of a few synthetics including perilla aldehyde and g-terpinene(4). Thorough testing is the consumer’s best protection.

Carbon 14 Isotope Testing
Carbon 14 isotope testing is a way to identify the origin of a molecule through the building blocks that make up the molecules. Carbon 14 is a radioactive isotope of carbon, meaning that it will slowly decay over time. Carbon is the building block of life, and we live in a carbon-rich environment. Plants transform carbon dioxide, through photosynthesis into sugars, then into an incredible variety of molecules within the plants, which are then taken up by animals, and so forth. Because carbon breaks down over time, and its half-life is roughly 5700 years, this means that nearly all the Carbon-14 will be gone after about 10,000 years. Petroleum, created by the decay of dead beings over hundreds of thousands of years, well shielded from our carbon-rich environment and the processes necessary to produce it, will contain no Carbon-14(2). Therefore this type of testing is a useful tool to spot the presence of petroleum adulteration through the absence of Carbon-14.

Missed Part 1 and Part 2? Or, continue reading Part 4 in our adulteration series.


1). The Essential Oils Revolution (May 13, 2015) [Video] Robert Pappas discusses essential oil adulteration. Retrieved from

2). Alexis St-Gelais (March 17, 2016) Quality Control 101. III. Is Carbon 14 Testing a Reliable Method to Detect Adulteration? Phytochemia Blog. Retrieved from

3). Satyal, P. & Pappas, R. (2016) Adulteration analysis in essential oils. International Journal of Professional Holistic Aromatherapy 5(2).

4). Burfield, T. (October, 2003) The adulteration of essential oils – and the consequences to aromatherapy & natural perfumery. Retrieved from

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