Most essential oils worldwide are produced for the flavor, fragrance and toiletry industries. Because these industries have no need for a natural product, these oils are usually industrially processed. It is common for "nature-identical" synthetic substances or other compounds not originating from the plant to be added. We strongly recommend that you use essential oils that are produced for aromatherapy only.
Therapeutic Effectiveness
For an essential oil to be useful therapeutically, it must be of very high quality. This depends upon the climate and geography where it is grown, what kind of farming methods the farmer uses, how the plant was harvested and how the oil was distilled.
Many flowers like violet, gardenia, freesia or lilac are not available as an essential oil because they are too delicate for distillation, too expensive or spoil too easily. Artificial oils may smell surprisingly real to an untrained nose, but they are not therapeutic. The best way to be sure of purchasing a true essential oil is to read the label, ask questions and find a company that is trustworthy.
Ask your retailer what he or she knows about the supplier:
1. Is the country of origin known?
2. Does he or she know the botanical species?
3. From which part of the plant was the oil distilled?
4. How was the oil produced?
Ask about the extraction method used to produce the essential oil:
Most essential oils are steam distilled. During distillation, the fragrant plants are exposed to steam until the essence evaporates. The oil-laden steam then rises through tubing, where it is cooled. When the steam condenses, the oil is found floating on top of the water and can be easily separated out. Master distillers know the right pressure, temperature and duration for each kind of oil.
Citrus oils are often cold-pressed to derive a better aroma. The peel is shredded and then mechanically pressed. The resulting liquid is filtered or passed through a centrifuge to skim the oil off the top of the liquid. Because many growers spray pesticides directly on the peel of citrus fruits, it is important to look for organic, cold-pressed citrus oils.
Oils like Coriander and Ginger, which are made from dried plant material, are sometimes extracted under pressure, using liquid CO2.
Blossoms that are too delicate to withstand high temperatures are sometimes extracted by solvents. Jasmine and Rose are sometimes solvent extracted. The plant material is put in a solvent like hexane. The solvent is then removed by evaporation; the product is mixed with alcohol to remove waxes and then distilled to remove the alcohol. Absolutes retain a miniscule trace of solvent.
How to read the label
A supplier of good-quality essential oils will include information about the source of the oil on the essential oil label:
Latin Binomial – to avoid confusion, the label should contain the two-word Latin botanical name (Latin binomial) for the plant from which the oil was derived. For example, all Eucalyptus oils are not alike. Eucalyptus globulus is a great decongestant and antibacterial oil, but it is too strong to use in a baby's room. Eucalyptus radiata is wonderful and safe for keeping your baby's nasal passages clear so you both can have a good night's sleep. Eucalyptus citriodora is a good insect repellent. Moreover, Thyme, Pine, and Chamomile are several commonly used oils that have different subspecies.
How It Was Grown?
Certified Organic oils – are distilled from plants grown without the use of pesticides. An organic certifier gives organic certification to the farms that follow strict guidelines (in the U.S. these guidelines are set forth by the USDA's National Organic Program (NOP).
Wildcrafted oils – are made from plants collected in the wild. Many people consider these oils to be the most potent.
Select-farmed oils – come from farms that are working toward organic certification or that take particular care in the growing process.
Toxic oils – a few oils can be very toxic. These oils should have a caution on the label and should only be used by trained aromatherapists. White Birch, Sassafras, Thymus zygis, Hyssop and Camphor are a few of these.