The length of time an essential oil will last without deteriorating is what is referred to as shelf life. The shelf life of aromatic oils is known to vary greatly, and their lifespan can be altered by a good number of external factors. The deterioration period may be somehow difficult to state, since there are too many factors involved.
To begin with, the shelf life of aromatic oils is dependent on the substance constancy, and anything that may modify or interfere with the chemical stability. The most common external factors that are known to pose threat to the chemical stability of aromatic oils include: air, heat and sunlight. A large percentage of essential oils have shelf life of no less than a couple of years, if stored and maintained in favorable conditions.
Why Essential Oils Deteriorate
All aromatic oils are not the same as far as their volatilities and chemical compositions are concerned. You will probably agree with the fact that aromatic oils made of the most volatile and most reactive chemicals will be the ones to fade easily. For instance, citrus oils are known to be famous for not lasting long. You should know that needle oils and citrus oils are made of high chemical constituents that are known to react readily with oxygen, making them have a shorter shelf life as far as aromatherapy oils are concerned. There are some aromatic oils that possess similar smell as lemon, but they are not citrus. These oils definitely have a high chemical composition that reacts easily with oxygen; thus they have a shorter shelf life. These oils do include the following: eucalyptus, Melissa, and lemongrass.
Shelf Life of Aromatic Oils
The easiest way to determine the shelf life of an essential oil is by simply considering its volatility. According to research, oils that deteriorate easily are normally irritating to the skin, and you need to buy them in small quantities, and use them within the shortest time possible. You should give a shelf life of not more than eighteen months to essentials oils that are highly volatile, such as peppermint and citrus.
Therefore, you should buy these oils in small quantities and provide them with the best storage conditions. Make certain that you will exhaust them within a year, and at most eighteen months. Essential oils that have mid-level volatility, such as clary sage and rosemary can have a shelf life of two to three years. On the other hand, aromatic oils with stable volatility will last indefinitely. Aromatherapy oils that show excellent stability and prolonged shelf life include patchouli, Vetiver and sandalwood.
Estimated Essential Oils Shelf Life Based on Volatility (Estimated Duration)
6-8 years: Vetiver, Sandalwood, Patchouli, Myrrh, Cedarwood
4-5 years: Ylang-Ylang, Roman Chamomile, Petitgrain, Peppermint, Palmarosa, Lavender, Ginger, German Chamomile, Geranium, Clary Sage, Basil
3-4 years: Vanilla, Tea Tree, Neroli, Clove, Black Pepper, Bergamot
2-3 years: Lemongrass, Thyme, Laurel, Juniper Berry, Frankincense, Helichrysum, Pine, Fir Needle, Eucalyptus, Cypress
1-2 years: Grapefruit, Lemon, Orange, Mandarin, Lime, Nutmeg
Storing Essential Oils
The key factor to prolonging the shelf life of aromatic oils is by providing them with proper storage conditions. Storing them can be simple when some careful precautions are observed. While aromatic oils do not go bad, they can easily lose their usefulness and fade. Some of the oils may oxidize and at the same time lose both their fragrance and therapeutic benefits. The most recommended storage bottles should be amber or blue in color. These two colors will diffuse light that may try to get into the oils.
Dark glass bottles are considered the best for storing essential oils. You should avoid buying oils that are packed in clear bottles. Since you are not in any position to be able to tell how long the oils have been in such containers. And how long have the containers been exposed to light. Chances are that the oils’ chemical compositions might have been tampered with. And the worst case scenario is that their shelf life may have been tremendously reduced.
Not all essential oils have limited shelf life, as you have seen in the table. Basically, the shelf life of aromatic oils varies accordingly with respect to their volatility. Therefore, you choice of essential oils should factor in their volatility. And how long you will use them. You should always remember to store your essential oils in dark glass bottles. If possible, you can store the bottles in essential oils case or box.