Quality control of essential oils is the single most important issue for any reputable company trading in aromatics. Every company likes to make claims about the purity of their oils but the uncomfortable fact is that there are a number of unscrupulous suppliers who are willing to adulterate their products. Simply using the price of an essential oil as a guide to its purity is no guarantee … it is not true that a high price will ensure a high quality product. This is because there are many other factors to be considered; how well sourced an oil is, the quantities bought, the overall efficiency of a company, their marketing and advertising budgets and their ethical standpoint to name but a few.
In fact there is no 100% certain way of testing an essential oil for purity! Essential oils, like all other natural products, will vary from one year to another. In some cases, like geranium, there can be extreme variations in oil extracted from plants growing in different parts of the same field, as well as variations within the same area from one year to another. The plant, the soil, the weather and the micro-climate all affect the odour profile and the constituents in the oil. So how do we define and measure the quality of an essential oil?
One way of trying to define quality is to identify a characteristic odour profile, against which you can compare the oil. But how do you determine what that odour profile should be? For example, bergamot oil from Sicily has a completely different profile to that of bergamot from the Ivory Coast: so should there be one standard for both or two different standards for bergamot? Lavender is a Mediterranean species and as such it needs hot sun and well- drained soil. If lavender oil doesn’t get enough sun the camphor content in the oil remains too high and the floral characteristics do not develop: it will also have different therapeutic properties. Conversely peppermint likes moisture and grows well in damp conditions.
At Aqua Oleum we believe that climate should be taken into account when defining characteristic odour. At present, international standards do not recognize the origin of an essential oil as a factor. Due to the difficulties described, quality parameters for essential oils are very wide. It follows that the wider the parameters are, the more scope there will be for adulteration. We have therefore developed our own strict definition of characteristic odour using our own company records and having had over 30 years of experience in the field. We also work closely with trustworthy suppliers and growers to ensure the quality of our oils, which includes examination of their GC / MS traces (see EDUCATION). Thus, we ensure that all our oils meet the following criteria:
- 1. The plant must be the mother species.
- 2. The plant must be grown in an area where the species is indigenous.
- 3. The oil must be extracted from 100% named botanical species.
- 4. The extraction technology should extract the complete oil rather than a fraction (as shown in the GC/MC trace).