Many of us consider our essential oils an investment in our health, a way to naturally keep our bodies and homes in tip-top shape. Storing your essential oils correctly is the best way to protect that investment.
The Shelf Life of Essential Oils
You may have heard the myth that essential oils with expiration dates on them are not “pure” essential oils. But the FDA requires any essential oil that may be used internally (that is, put inside your body) to carry an expiration date, just like medications and vitamins. That’s because over time, the chemical composition of all these items changes, eventually leaving you with a different substance than what you started with. This goes for all essential oils, not just those that come with an expiration date on the package.
Different kinds of essential oils change at different rates. For example, sandalwood and patchouli actually get more potent over time, while oils derived from wood or roots can last up to ten years. It pays to know a little chemistry when it comes to determining an essential oil’s shelf life. The numbers below represent the average shelf life of essential oils when they are stored properly:
- Essential oils high in monoterpenes or oxides have the shortest shelf life, usually about 1-2 years.
- Those with more prenols can last up to 3 years.
- Oils higher in ketones, monoterpenols, and/or esters generally last about 4-5 years.
- Essential oils that contain high levels of sesquiterpenes or sesquiterpenols usually last up to 6 years.
What’s the difference with these ingredients? Their evaporation rate. Essential oils are considered volatile, which means they are easily evaporated at normal temperatures. Lighter components, such as monoterpenes, evaporate more quickly than do heavier ones like sesquiterpenols. Essential oils are also prone to oxidation, so any interaction with oxygen will begin to change their chemical composition. Proper storage helps protect against both evaporation and oxidation.
How to Store Essential Oils
Even if you’re relatively new to using essential oils, you know that a little goes a long way. So one bottle could last a very long time—if it’s properly packaged and stored. Your essential oils have three primary enemies:
- Air: Any exposure to air will cause oxidation, which usually progresses more and more rapidly over time.
- Light: Although not enough research has been conducted to understand exactly why, exposure to sunlight and other UV light will cause essential oils to break down.
- Heat: Heating essential oils above normal room temperature accelerates evaporation, quickly leaving you with an entirely different compound than you started with.
You’ve probably noticed a running theme here: essential oils are prone to chemical interaction with their environment—which also includes their containers. This is why it’s best not to store essential oils in plastic: the essential oils can interact with certain kinds of plastic, potentially causing the plastic to break down or melt over time. Again, the essential oil’s composition determines how it will interact with plastic; citrus oils are particularly well known for interfering with the chemistry of plastics. doTerra uses only HDPE plastics for its plastic parts. Plastics bearing the #1 or #2 are also safe.
Tips for Storing Essential Oils
- If your oils come with a reducer cap (plug), always keep that in the bottle to reduce exposure to air when you open the oil.
- Though reducer caps don’t usually come into contact with oils when you’re not using them, they may still break down over time. Keep extras on hand so you can replace reducer caps that show any signs of deterioration.
- If your oils don’t come with reducer caps, invest in a glass dropper. The dropper itself shouldn’t be used as a lid because the bulb is made from a pliable rubber. Clean the dropper with alcohol after each use and store it in a glass jar.
- Store essential oils in dark glass bottles, which help block UV light. Keeping all your bottles in a wooden box or padded carrier case will further protect them from UV exposure.
- The ideal storage temperature is 40-80 degrees, so never leave essential oils where they’ll be exposed to heat, such as a window sill or in your car.
- You can refrigerate essential oils. Cold storage might change the consistency of some essential oils, but it will not change the oils’ chemistry.
- When you’ve used about half of a larger bottle of essential oil, transfer the remainder to a smaller bottle: less air in the bottle helps slow oxidation.
- Signs of oxidation include cloudiness and a change in smell. You can still use oxidized oils for cleaning or in your diffuser, but do not use them internally.
- When you cook with essential oils, don’t add them directly to food as it cooks. Instead, add them to your finished dish or drink.
Have a question about storing or using essential oils? I’m happy to help! Contact me today.