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What to look for when shopping for oils
When using essential oils for aromatherapy, it is important to choose pure, unadulterated oils. Essential oils are widely used in food and cosmetics and these industries demand consistency, so oils are sometimes altered so that they have the exact same chemical make-up year after year. In nature, this does not happen. Essential oils can be different from year to year due to different growing conditions, weather, storage conditions, and distillation. Where in the world the oil comes from can make a difference as well. As an example, Lavender oil from plants grown at high altitudes is said to be superior to oil from low altitude plants. Lavender from France and Bulgaria is also prized (and pricey) although Lavender grows in many other parts of the world as well.
So how can the essential oil consumer tell if a product is pure and unadulterated?
The short answer is it is difficult. The best way is to find a reputable retailer that you trust. Words like “pure” and “therapeutic” and even “certified pure” are thrown around a lot, but there is no certifying organization for essential oils, and an oil does not have to be 100% pure in order to be labelled as “pure.” In fact, it may contain only 10% essential oil and still be labelled pure.
Some oils are blended with other oils of the same species (e.g. blend an expensive lavender with a cheaper lavender), or even other species (e.g Melissa is very expensive and some oils that claim to be Melissa are actually a blend of lemongrass and citronella). Other oils may be adulterated by adding in components (e.g. linalool) so that the chemical makeup of the oil matches a particular standard (as happens in the food and fragrance industry where consistency is required from year to year).
Who should I buy from?
I recommend choosing companies that serve the aromatherapy market. Consider that oils from suppliers catering to the aromatherapy market are more likely to value sourcing pure, unadulterated oils than suppliers catering to soap makers. The heat generated in soap-making can evaporate off the most volatile components of an essential oil possibly leaving the remaining essential oil altered. This means that it is less imperative that soap-making essential oils be premium quality as they will not emerge from the soapmaking reaction unscathed. This is not to say that soap supply stores do not carry quality oils, but it is something to bear in mind.
What about price?
Finally, consider price. If a price is too good to be true, it probably is. Quality oils are available for reasonable prices. The most expensive oils are not necessarily better than moderately priced ones. You must compare apples to apples. Look at multiple suppliers and see what comparable oils sell for.
For example, let’s say Company A sells Lavender (Lavandula Angustifolia) from Bulgaria. When you check Company B, check that the botanical name matches (L. Angustifolia) and that it is also from Bulgaria. You cannot compare the price of one oil to an oil of a different species or from a different growing area. That is like comparing a Burgundy from France to a Washington Pinot Noir.
One final point to remember is that some essential oils are sold by multi-level marketing companies, who need to factor in commissions for many tiers of salespeople. The oils may be of good quality, but likely overpriced.
Most aromatherapy books will tell you to look for the following to identify a reputable supplier:
- Look for the Latin botanical name of the plant on the label (e.g. Lavandula officinalis) and in some cases, the chemotype (e.g Rosemary ct verbenone, Rosemary ct 1,8 cineole)
- The label should state the country of origin and method of extraction (steam, cold pressed, etc.)
- Look for oils that are in colored glass. They should not have rubber dropper caps.
- The supplier should be able to provide you with a certificate of analysis upon request. Of course the average person will not know what to look for in a CoA, but its existence is in itself a clue to the consumer that the company has gone through the time and expense to verify the constituents of the oil.
- Gas chromatography and mass spectrometry can detect adulterations and many larger, reputable companies will perform these tests on their oils. Smaller companies may not have the budget to do their own testing, but may still source excellent oils. They should at least be able to provide a CoA from their supplier.
Simple home test: You may be able to gain some information about the purity of an oil by placing a drop of oil on a piece of paper. If it evaporates completely, leaving little or no stain, it is likely pure. If you see an oily residue remaining after a couple of days, it was probably diluted with some other ingredient. This test will not work for some of the heavier, thicker oils, nor will it work with cold pressed citrus oils. Obviously it is not 100% reliable. This simple test may help to identify oils that have been cut with carrier oils.
Wild-crafted, Organic, or not?
When using essential oils for therapeutic purposes, I would recommend seeking out wild-crafted oils when possible. Why? Since essential oils are part of a plant’s defense mechanisms, it stands to reason that if a plant is in the wild and not coddled by cultivation methods it will produce superior oils in its own defense.
Organic oils are the next best option, and is strongly recommended for all cold pressed citrus oils. As an example, citrus oils such as orange, lemon, and grapefruit are extracted from the outer peel of the fruit where pesticide residue is most likely.
Another consideration is how susceptible a plant is to disease or pests. Some plants grow without much need for pesticides, in which case whether you buy organic oils or not may not make a difference. To a certain extent, price may be a clue here. The difference between an organic oil’s price and a conventional oil’s price may indicate how difficult it is to grow that plant organically. I would love to see someone develop a list of the most important and least important oils to buy organic (like the fruit and vegetable ‘dirty dozen’). If you come across such a list, please contact me with a link, I would love to both read it and share it.
Finally, conventional oils can still give therapeutic benefit. There may be a slight chance of residual pesticides, but see the link below on essential oil testing in which the conventional oils tested had no contaminants.
Does method of extraction matter?
Yes, it can. Steam distillation and cold pressed are the most common methods of extraction. Cold pressed oils will yield an oil closest to its natural state. The following are the primary methods of extraction:
- Steam distillation: Plant material is placed in a still and heated with water. The steam rises through the plant material and collects and then condenses in a chamber. A hydrosol and essential oils are the result. As essential oils are not water soluble, they can be separated from the hydrosol.
- Expression: The plant part is squeezed under pressure to extrude the oil. This process can generate frictional heat, so the label “cold-pressed” means that the heat generated was controlled to stay under 120 degrees.
- Solvent extraction: Some oils cannot tolerate the heat of steam distillation, but have too little oils to use expression. Solvents such as hexane or ethanol can be used to extract these oils. The oils “dissolve” in the solvent, and then the solvent is evaporated off. Some have concerns that solvent residue may remain in the essential oils, however that may have been an issue with older methods such as benzene extraction, but hexane leaves so little residue that it is measured in parts per million.
- CO2 Extraction: This is a newer method and is expensive, but yields good oils without solvent residue. Carbon dioxide is brought to a hypercritical state where it is neither gas nor liquid, which is achieved through temperature and pressure. The CO2 acts as a solvent to the plant material and when the pressure is removed, it reverts to a gas, leaving essential oil.
- Enfleurage: Rarely used anymore and labor intensive. Plant material is embedded in fat on trays and left for the fat to absorb the oil. Plant material is replaced a few times until the fat is saturated. Alcohol is then used to separate the fat from the plant oil. Used for some florals like Jasmine.
Dig a little deeper:
More information on purity and grading in essential oils can be found in this article at Nature’s Gift.
To read about a group of people who are putting the essential oil retailers to the test, see this article about independent testing of essential oils. The results are re-assuring!