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Therapists can learn to use pure essential oils safely and successfully through a National Organization for Holistic Aromatherapy (NAHA) certified program of study. However, some aromatherapy information typically skimmed over and forgotten about is this: most pure essential oils don’t last forever. There are several things anyone purchasing, storing and using pure essential oils must know for aromatherapy to accomplish what it is capable of.

Luckily, pure essential oils do not go rancid. However, they do degrade through the process of oxidation. Heat, sunlight and air can all break down the chemical structure of essential oils. Additionally, the complex and varying chemistry of pure essential oils means that each oil has a different rate of degradation. Although there are too many variables to accurately predict how long an essential oil will be at its most potent, there are several tips that will help you determine your oil’s lifespan.

Buy Carefully

You can only control the environment of your oils after you purchase them. Thus, knowing what to look for when buying essential oils can help ensure their longevity.

1. Dark colored glass; no dropper – Dark colored glass helps protect the oils from the oxidative properties of ultraviolet light. Avoid purchasing essential oils that are stored in bottles with a rubber dropper incorporated into its cap. Pure essential oils can turn rubber into gum and quickly ruin the oil.

2. Evaluate your supplier – The closer to its distillation date, the more potent an essential oil will be. Suppliers specializing in aromatherapy typically have a high turnover of oils, ensuring a fresher purchase. When purchased from a store, they may have been sitting on the shelf for a long time. If you do buy from a store, make sure they are not displayed under hot lighting or in direct sunlight, and check that they don’t have a layer of dust on their caps.

Store Carefully

Once you have the essential oils, the steps you take to properly store them will either make them last long or render them useless.

3. Know their age – Although you are not likely to know the date an essential oil was first distilled, you can keep track of how long you have owned them. Devise a way to mark your oil with the date of purchase so that you can be alerted to when one might be approaching the end of its life.

4. Minimize oxidation – Since heat and light oxidize essential oils, always store essential oils inside dark glass bottles in a cool, dark place. In addition, keep your oils in the smallest possible sized bottles to reduce the amount of empty space in the container. Because the empty space in a bottle is occupied by air, more empty space hastens the rate of oxidation. For this reason, experts advise rebottling oils into smaller bottles as they are used.

Check your Stock

Again, based on the substantial number of variables in determining the viability of a pure essential oil, there are no guarantees of how long it will last. Some experts tout that well cared for oils will last for one to two years, while others claim this time frame is longer. However, terpene-rich oils such as citrus and some coniferous essential oils oxidize quicker than other oils, while the thicker viscosity essential oils, including Patchouli, Vetiver and Sandalwood mellow and improve with age. The only surefire way to know if your oil is still viable is to check it yourself.

5. Look and smell – Through a little bit of effort, you should be able to detect an essential oil that has passed its prime. Look carefully to see if your oil appears cloudy or thick, both of which indicate oxidation. Since drastic changes in odor also indicate oxidation, smell your oils to see if they have lost their characteristic odor or if they smell acidic. In either case, the therapeutic value has diminished, requiring its proper disposal.

Although the skilled application of essential oils can dramatically improve a person’s health, they must be suitably maintained to do so. Along with the knowledge gained through a NAHA certified course, careful purchasing, storage and inspection of pure essential oils allows bodyworkers to fully appreciate the therapeutic value of aromatherapy.

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