An important characteristic of a good essential oils is that the oil is pure.
PURITY
Purity comes through how the essential oil is produced, starting with the plant itself, the extraction process, then culminating in the bottling process. Purity can be monitored by thorough testing. Without rigorous testing, there is no way to achieve purity–because you would be flying blind. There are too many factors. There are so many ways that you can get it wrong, and only one way to get it right, every time. Testing is your guide to achieve pure.
WHAT’S PURE?
First, what does a pure essential oil mean? Pure means it is free from fillers, pesticides, solvents, and additives. It also means that it contains only essential oils produced by the plant it purport to be from, and that the compounds are in the right ratios and percentages. Pure means it is what you want it to be. It is what you need it to be.
To put it simply:
Purity means (1) free from fillers, pesticides, solvents, and additives; and (2) is natural (not synthetic).
Impure means there is either (1) other stuff in there or (2) it is not the way nature made it.
WHY PURE?
If an essential oils is pure, you are more likely to get the therapeutic value you are seeking (assuming the oil has been properly obtained from a therapeutic source).
If the essential oils is not pure, you may not receive the therapeutic benefit you desire. Moreover, if the oil is not pure (whether produced synthetically in a lab or carelessly stripped from contaminated plants), it may even be potentially toxic.
Thus Purity is very important to justify the very purpose of having an essential oil.
WHY TESTING?
Producers can monitor and thereby ensure purity through consistent and sophisticated testing. Testing can detect many impurities:
1) Harmful traces of ingredients
2) Chiral oriented constituents
3) Constituent percentage range
4) Adulteration
These are all problems that come with making (or adulterating) essential oils in a laboratory.
THE PROBLEM WITH SYNTHETICALLY PRODUCED ESSENTIAL OILS
TRACE INGREDIENTS
Here is an example of an essential oil compound produced in a lab:
Methyl Salicylate is one of the main active constituents found in Wintergreen essential oils. This compound is commonly synthetically produced and added to muscle rubs. However, when producing this compound in a laboratory, it is impossible to produce an end product that does not have trace amounts of the ingredients used to make the product. Here is a very simplistic representation of the formula to make Methyl Salicylate.
Phenol(Strong Acid)+Carbon dioxide(poisonous)+sodium hydroxide(Very Caustic)+hydro-sulfuric acid(Very Dangerous)+methanol(Poisonous) = > Methyl salicylate (with trace poisons and acids)
As these chemicals are mixed together in order, trace amounts of the ingredients remain in the final solution. There may also be assisting catalysts or solvents. Many of these ingredients are so dangerous, the scientists mixing the solutions must wear protective clothing and work under a fume hood.
These compounds are very inexpensive to produce in a laboratory. Sometimes they are cheaper to produce than water. Thus synthetically produced essential oil compounds are very widely used in the market today. But they are impure because of the small trace elements, which will always be present when making the constituent in a laboratory.
Nature uses a different method.
Nature produces essential oils on a cellular level through DNA instructions with the assistance of proteins. Although the end molecule is in most cases exactly the same, there are no traces of harmful chemical solvents or caustic acids.
CHIRALITY
Regardless of the harmful trace ingredients, most of the time the molecule produced in a lab is exactly the same as the molecule produced by nature. There are sometimes a difference, however.
As it turns out many molecules (not all) have a left and a right-hand orientation. This is called Chirality – non-superimposable mirror images. It is similar to your right and left hands, they are mirror images that cannot be superimposed on each other.
The interesting thing is that if we synthetically produce the molecules in the lab, we get an exactly even left-hand right-hand orientation mix. Nature, however, only produces one orientation.
This is important because the differently oriented molecule may often have different characteristics or traits. This can lead the synthetically produced solution of essential oil particles to be less therapeutic. In some cases the opposing molecule orientation may be harmful or counter effective or even dangerous.
CHEMICAL CONSTITUENT PERCENTAGE RANGE
Yet another problem with synthetically producing essential oils in a lab. You only make one constituent at a time. A nature-produced essential oil has anywhere from 30 to 300 essential oil compounds in the solution.
It may be true that just a few of these seem to provide the bulk of the therapeutic benefit, but the natural combination of all the constituents has proven over and over again to have superior therapeutic results.
Scientists have tried for years to select one compound from an essential oil, and just produce that compound in hopes to capture the therapeutic benefit without all the other “junk” nature has thrown in there.
However, it has been shown over and over that the minor compounds interact with the main compounds to produce a more complete result. The “junk” was actually working – nature was producing it for a reason. That is, when the essential oil has just the right amount of each constituent, it works much better – provides a higher therapeutic result.
ADULTERATION
Essential oils produced by nature may also become impure. There are many reasons for this.
- Enterprising essential oil companies may seek to change, enhance, or substitute an essential oil by adding an essential oil from another (albeit similar). For example Cassia is an essential oil very similar in aroma and therapeutic qualities to Cinnamon. Testing from trained scientists have discovered that some companies are replacing or “spiking” their Cinnamon essential oil with Cassia.
- Another way essential oils can be adulterated is through the use of pesticides or plant contaminants. These pesticides find their way into the essential oil, and contaminate the oil with potentially harmful chemicals.
- Cheap producers use additives and fillers to thin out or somehow change an essential oil sample. This may lower the cost of the essential oil, but it also decreases the therapeutic value.
- Sometimes a cheap way to extract essential oils is through the use of solvents. However, these solvents end up in the essential oil solution and ultimately on or in the bodies of the end user.
Essential oil tests can be carried out by trained scientists can detect these adulterations.
TESTING
Here are just a few of the tests that can be performed on essential oils:
-
Core Tests
- Organoleptic-sensory evaluation
- Specific gravity
- Refractive index
- Optical rotation
- Gas Chromatography Mass Spectrometry (GCMS)
- Fourier Transform Infrared Spectroscopy (FTIS)
- Isotope Carbon 14
- Heavy Metals / Pesticides
- TPC/Microbial
-
Additional Testing
- Stability Testing
- Biochemical Pairing
- Taxonomy
- VOC
- Thin Layer Chrom
- LC/LCMS
ORGANOLEPTIC OR SENSORY EVALUATION
The first method of testing is very simple and doesn’t require any equipment—although training and experience improves the test.
It is simply using your raw senses. And many people do this naturally. For instance, when people smell Lavender, they can tell right away whether it is likely good quality or pure. How an essential oil smells, the feel of it, it’s thickness, the color or look of it, and if it is safe for tasting, the taste of it.
This method of testing seems obvious, but it is a simple first step, and sometimes it can quickly detect if something is wrong. More testing is necessary, but this is a notable starting point for any scientist.
SPECIFIC GRAVITY
Specific Gravity is the density of a substance (that is how much mass is contained in a fixed volume). This is measured at a specific temperature and atmospheric pressure.
The specific gravity of water is 1.0 g/ml.
Oil is usually less than this and floats.
Not all, however. Clove, Wintergreen, and Cinnamon sink depending on their quality.
This test can easily detect when something is not right about the sample.
REFRACTIVE INDEX
As light passes through a substance, it slows down. The ratio of the speed of light in a vacuum compared to the speed of light as it passes through a substance is the refractive index.
This ratio is responsible for light seeming to bend as it passes through water, glass, or a lens.
Each substance will have a different ratio.
When this ratio is compared with historical records of good samples, those administering the test can determine whether something is impure and has been adulterated.
OPTIC ROTATION
Optic rotation merely sends polarized light through a substance and then measures how that light rotates.
Polarized light means light waves that oscillate in a synchronized direction.
When this direction or angle changes as light passes through a substance, we can learn things about the molecular makeup of the substance.
Important here is we can detect the chirality of molecules in an essential oil solution. Chirality means whether the molecule is in left-hand or right-hand version. Nature curiously only produces one orientation, so this test can inform scientists whether the molecule was made by nature or man, or whether it has been changed in any way.
GAS CHROMATOGRAPHY MASS SPECTROMETRY (GCMS)
The Gas Chromatography Mass Spectrometry (GCMS) is the test most relied upon by essential oil scientists. It gives scientists so much information.
It works by injecting the essential oil sample into the apparatus where it is vaporized and propelled through a tube, which separates compounds based on volatility. As these groups of compounds pass through electric and magnetic fields the specific compounds are measured in terms of mass and quantity.
A typical graph is produced, which tells the scientists how many molecules of a specific mass are found in the sample.
Can you see how super helpful this is to scientists to see how pure the substance is?
Impurities can be detected and measured.
The quantity of each type of molecule is measured.
This test can also detect the ratio of a certain molecules compared to others in the sample, which gives us clues as to the therapeutic benefit we can expect from that sample. This ratio can also tell us if the essential oil is pure. Typically an essential oil will contain a certain ratio of a particular molecule found in that essential oil. When a molecule is discovered outside this ratio, it is a sign that something is wrong and the sample is impure, contaminated, or adulterated.
For example: the ratio of terpinen-4-ol found in Melaleuca is normally between 30% and 55%. If it is not, the abnormal is an indicator that something is wrong, that the sample is impure.
FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIS)
The Fourier Transform Infrared Spectroscopy (FTIS) is another test that projects light through a substance. It gives data like a Gas Chromatography Mass Spectrometry (GCMS) test.
It works by projecting Infrared light through the substance. This test can detect the characteristics of the bonds between the different atoms in the sample. It does this by measuring patterns in what infrared radiation is absorbed by the sample and what passes through.
With computer analysis, this test can detect the types of and quantity of molecules present in the sample, and their chirality.
This test substantiates what scientist learn from other tests and can help give a better picture of the quality of the essential oil as it actually is.
CARBON 14
Carbon 14 is regularly used to date an object. The theory is that the different levels of Carbon 14 an object has is an indicator of when the object was alive. Synthetically produced essential oil compounds use carbon from sources that are sometimes very old, and this test will illustrate that. This is an indication that the essential oil is likely synthetically produced from carbon found in mineral sources or fossil fuels.
HEAVY METALS/ PESTICIDES
Simple tests can be done to determine whether the sample contains heavy metals or pesticides.
TCP/MICROBIAL
Samples should also be tested before and after bottling to ensure they are safe from microbes.
CONCLUSION
This science behind the purity label is what gives me confidence in the essential oils that I choose to use. I will only use the best, most pure essential oils produced by nature in the form nature intended.
There are more tests that can be performed, but these are the main ones and they will give you an idea or the rigor a quality essential oil company will go through to ensure that essential oils are produced in the most pure form.
To sum up Testing and Purity, think about the reason you want to use essential oils. You want them to make you well (to provide a therapeutic benefit).
It is very important that your essential oils are pure because purity helps make them safe to use. And in some cases, it also means they will work.
But purity is only halfway there. If the essential oil is pure, but not therapeutic, it is essentially useless.
Next we will talk about the importance of sourcing and producing potent and therapeutic essential oils.
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