“DID YOU KNOW” A Little About Essential Oil Chemistry
Essential oil chemicals are naturally found within the plants. These chemicals are what give the oils their aroma and their natural therapeutic effects. I love the way that Aromahead Institute defines essential oils from a chemistry perspective:
“An essential oil is a collection of many molecules, and is made up primarily of carbon, oxygen and hydrogen. Every essential oil has a unique set of carbon compound ingredients. For example, the ingredients of Rose oil are different than the ones in Pine. When you smell Rose or Pine oil, what you are actually smelling – the substance that enters your nose – is a unique set of carbon compounds that your brain has learned to identify as the scent of “Rose” or “Pine”.”
Essential oils, while in the plant, are constantly changing their chemical composition. This happens so that the plant can adapt to the ever-changing environment.
Scientific research has shown that plants produce essential oils for a variety of purposes:
- to attract pollinators
- as defense against insects and other animals
- for protection of the plant due to their antibacterial and antifungal nature
- to keep away other plants competing for nutrients
As a consequence of these changes, even the same plant growing in the same area can produce different essential oils from year to year. Other factors that contribute to this adaptation of essential oil chemical components are weather, time of harvesting, and oil extraction method used. Why bring any of this up? The answer is that these differences mean that the percentages of chemical components in the plant might change and the aroma of the oil may be different. Chemical component changes may change the natural therapeutic effect desired. Have you ever noticed how oils from different sources and even the same sources year to year may smell different?
A good example is Helichrysum from Corsica is rich in specific esters that are strong antispasmodics. Helichrysum from Croatia has almost no esters but is rich in sesquiterpenes and ketones known for healing damaged skin. Looking at the two pictures below we would not see these differences, but they are definitely there from a therapeutic and aromatic perspective.
Helichrysum from Corsica Helichrysum from Croatia
How do we know what we are really getting when we buy an essential oil?
The best way to assure the quality and purity of the oil is with what is called GC/MS testing. (Gas Chromatography/Mass Spectrometry.) Don’t get lost in these big terms. But, expect that your supplier of essential oils perform these tests because the therapeutic benefits and safety issues of essential oils are primarily determined by their chemical makeup. The testing can also determine if the oil has been adulterated in any way.
Looking back at the above Helichrysum example, the only way that we can know exactly what is in an oil is by GC/MS testing so that we can know more clearly what the best natural therapeutic use of the oil will be. Are we looking for a skin healing solution or an antispasmodic? Essential oil suppliers should have GC/MS testing sheets available for you when you purchase an oil from them.
There is so very much more to the subject of essential oils and chemistry. If you are an Aromatherapist you will have been exposed to much of it. If you are not an Aromatherapist maybe now you will want to explore the art and science or aromatherapy just a little bit more.