All essential oil consumers would love a perfect supplier of the purest oils at the fairest of prices. Unfortunately, many essential oil suppliers have come to rely on immoral practices to produce adulterated Essential Oils whilst labelling them as 100% pure.

Adulteration is the practice of modifying the composition of essential oils using various methods, this is so they may be sold at cheaper prices increasing the profit of the supplier.

This is were your own due-diligence comes in to prevent being mislead.We have broken down 4 best practices for the average consumer and 3 of the best evaluation tests for professionals. 

Average Consumer Best Practices

Seller background check :

When purchasing in general and in particular from Online marketplace sellers, make sure you are purchasing from a legitimate supplier with business and contact information being clearly visible on their external website. 

Does the supplier provide Safety Data Sheets, Certificates of Analyses or test reports which are easily accessible for each essential oil product on site ? 

Check the price :

The price of a singular Essential Oil is an easy way to identify whether they have potentially been adultered or not, though this does not guarantee that well priced essential oils are pure, it does however eliminate the significantly cheaper oils, this can practically be applied by having a rough estimate of the single essential oil prices of a couple reputable suppliers and then comparing with others, if the price is significantly it can almost certainly mean the essential oil has been adultered.

The disparity in price for lower priced oils may not be so clear, however for some  essential oils such as Rose Otto, Jasmine, Neroli, Sandalwood, Ylang ylang etc this becomes very apparent. Please make sure you are comparing the exact same botanical name, origin, plant part and extraction method. Some essential oils may have the same name but are priced differently due to having different origins etc.

Compare the scent :

Train your sense of smell. Although it can take a while to become a professional in conducting an organoleptic test, you still have the basic sense of smell to recognise a stronger scent. This is by no means a definitive factor, but can be an indicator of impurity. 

Local aromatherapist :

Apart from finding a credible supplier whose purity tests you can trust, perhaps the most reliable way to assess your essential oils would be to consult an independent tester and have them professionally tested, this can be your local aromatherapist or analytical laboratory.

 

Professional Consumer top 3 Practices 

GC/MS Test:

The most accepted analytical way of evaluating the composition of an essential oil is a GC/MS Test. A GC/MS test enables the identification of the different chemical components comprising an essential oil. GC splits the oil into its individual constituent parts depending on its molecular structure, while MS analytically identifies each constituent to produce results 'spectrum'.

In this way, an evaluator can conclude which components, along with their percentages, were present in the sample, much like a chemical 'fingerprint'. By comparing the results with a spectrum that represents a known, pure sample, the purity of essential oil in question can be easily determined.

It is important to note that natural variations are possible from batch to batch; the molecular make-up based on harvest time, location, season, and soil quality of essential oils may cause variation in the results, however the values for each chemical compounds will still have to fall within a standard range to be considered very likely unadultered.

In the contrary even a slightly adultered essential oil will likely fall out of the standard range by a margin. The delicate balance of compounds that makes each essential oil unique is essential to know you are receiving the right amounts of constituents.

Organoleptic Test:

Organoleptic test involves using the senses to closely examine the quality of an essential oil. The colour, texture or consistency, and finally the aroma can be evaluated.

In order for an organoleptic tests to be accurate it must be conducted by a trained professional aromatherapist, Organoleptic tests require a high level of concentration due to these tests having to be repeated many times with a large number of samples.

Physical Test:

This involves assessing the physical or physicochemical properties of an essential oil, such as: its density, optical rotation, refractive index, solubility with ethanol, and freezing point. For example, a pure essential oil is associated with a particular density relative to water. This value can therefore be measured in order to check whether the sample oil is pure or has been adulterated, 

Similarly, essential oils display optical activity, which involves their capacity to rotate polarised light; the degree of this rotation can be measured, along with its direction, using a piece of equipment called the polarimeter. The result can then be compared to a reference value such as those published by the ISO. In this way, the identity of an essential oil can be honed in on, and consistent outliers can alert to possible impurities or adulteration.

Other secondary practices: 

Isotope analysis: 

Isotope analysis is the identification of isotopic signature, the abundance of certain stable isotopes and chemical elements within organic and inorganic compounds. 

Microbiology testing:

Microbiology testing helps to minimise the risk of potential damage by microbes and to ensure the microbiology quality of your products is maintained.

Heavy metal testing:

Heavy metal testing shows the amount of heavy metal content in any given essential oil. When properly distilled, essential oils shouldn’t contain heavy metals.

Chiral analysis:

Chiral analysis refers to the quantification of component enantiomers of racemic drug substances or pharmaceutical compounds. Other synonyms commonly used include enantiomer analysis, enantiomeric analysis, and enantioselective analysis

FTIR: 

Fourier-transform infrared spectroscopy is used to obtain an infrared spectrum of absorption or emission of a solid, liquid or gas. An FTIR spectrometer simultaneously collects high-resolution spectral data over a wide spectral range.