What is the shelf life of essential oils?
Do essential oils expire?
These are important questions to answer.
Essential oils are not cheap. Well, some of them are very affordable, but some are quite expensive, and of course the bottles are quite small.
If you are into DIYing essential oils blends instead of buying blends pre-made, knowing about essential oils expiration and the shelf life of essential oils can be a big deal.
For example, let's say you want to save money by making your own essential oils blends like my Breathe Easy Blend, Hair Growth Blend, or Antibacterial Blend. However, if you end up having a bunch of left over essential oils that you end up tossing because they expired, then you end up not saving any money at all.
Anyhow, the topic of the shelf life of essential oils and whether or not essential oils expire is something that I have been wondering about for a long time.
Because I'm a money-saving-bulk-buying kind of gal.
I'm the gal who buys 25-pound bags of organic dried beans, 25-pound bags of organic coconut for my Homemade Coconut Chips and Easiest Coconut Milk, 25-pounds of chicory for my Nourishing Coffee Substitute — and yes, I have bought a lot of single essential oils to make blends from.
And I have a lot.
So for all of the other money-saving-bulk-buying folk out there, here are the facts on the shelf life of essential oils.
One Myth About Essential Oil Expiration
There are lots of myths running around regarding essential oils and one of them is this:
“If a company tells you that their essential oils expire, or have a shelf life, then they are not pure essential oils.”
That's not true.
Now, it is true that essential oils do not contain water, so they do not grow mold, mildew, or yeast, and additionally they have antibacterial and antiviral properties, but they do change over time and you need to know how in order to be able to use your essential oils safely and effectively.
Several things can affect the shelf life of essential oils and can cause them to not be as effective.
Essential Oils are volatile oils (they easily evaporate — that is why you smell them) and they can oxidize. If you know anything about the word “oxidize,” it means that it is affected by oxygen.
You've surely heard about “antioxidants” in foods and how they are good for you, right? They prevent, or help get rid of, the damage done by oxygen exposure that is called “oxidizing.”
In the same way that oxidizing affects foods (and your body), oxygen affects essential oils.
Things That Affect the Shelf Life of Essential Oils
Every time you open your essential oil bottle oxygen gets in. The oxygen reacts with the oil and oxidizes it, in the same way that exposure to the air causes an apple to turn brown.
According to Robert Tisserand's Book On Essential Oil Safety,
“oxygen can change the chemical composition of an essential oil by reacting with some of the constituents.”
Think about that. If you are changing the chemical composition of an essential oil, then you basically have a different essential oil than you thought you had.
The properties that you bought it for might not be in the essential oil any longer and there will be new properties — some of which might not be desirable.
There is varying information on this, however it is known that light is also damaging to essential oils. That is the main reason why it is recommended to store your essential oils in colored bottles, which apparently help to minimize this effect.
A study was done on Sweet Orange Oil in which the oil underwent significant changes in its composition when it was exposed to UV light at 20°C for 50 minutes. There were decreases in certain constituents and new constituents resulted. So technically the oil was a totally different oil after this exposure. (Source)
Fennel Oil has been shown to oxidize more quickly in light than in dark. (Source)
Heat also can affect the quality of your essential oils, however this has not been as widely studied.
Robert Tisserand, considered by many to be the foremost expert on essential oil safety, recommends keeping your essential oils away from heat and in cool areas, ideally in the refrigerator. (Source)
Heat would cause the volatile compounds to evaporate more quickly, but of course the lid of the bottle would need to be removed in order for this to happen.
It appears, from the studies that have been done, that the effect of heat on an essential oil will vary depending on the components of that specific oil with components such as citral, citronellal, and oils that are high in monoterpenes seeming to be more greatly affected by heat exposure.
Apparently, those essential oils that are extracted using CO2 are more prone to damage from heat than other essential oils, though the reason for that is not yet known. (Source)
Of course, if the essential oil is not exposed to oxygen, light, or heat (so it's unopened in a dark, cool place), then it should be fine. However, once you open the bottle, the deterioration begins and it is progressive with time. As you expose the essential oil to any of the above assaults, over time, the essential oil will change. If you regularly open your bottle to use the oils, then the effect will occur more quickly. Additionally, as you have less of a particular essential oil left in a bottle, it will be exposed to more oxygen and the effect on the remaining oil will be greater.
There are some essential oils that get better with time, Patchouli being one of them. Others that I have read about include Sandalwood, Rose, possibly Cedarwood, Vetiver, Frankincense (CO2), and Myrrh.
Are Old Essential Oils Dangerous?
Essential oils are made up of different components. There are lighter components and heavier ones.
The lighter components are the ones that evaporate first and so that would leave behind the heavier components. Typically, the lighter components are the ones that are gentler on the skin. So if you use an essential oil that has been around for awhile, your chances to experience irritation are greater.
Additionally, the chances of getting sensitized to the oil increase as well. As I mentioned in this post on Emulsifying Essential Oils, you can greatly minimize the chances of sensitization in general.
And as I mentioned above, when essential oils are exposed to light, heat, and oxygen, the components change. So what you end up with is a different oil than what you started out with.
So yes, old essential oils can be dangerous.
What is the Shelf Life of Essential Oils?
I'll write in more detail about this in the future, but for now, here are the basics.
Essential oils that have a higher quantity of monoterpenes or oxides have the shortest shelf life — approximately 1-2 years.
Those essential oils that have a higher quantity of phenols may last up to 3 years.
Essential oils that contain ketones, monoterpenols, and/or esters have a shelf life of approximately 4-5 years.
Essential oils with a higher amount of sesquiterpenes and sesquiterpenols can last up to 6 years.
Don't worry if all of this “terpene” and “ketone” and “….perpenol” stuff is confusing. We'll go over it more later :).
In the meantime….
The Essential Oil Safety Book
I referenced this book several times in this post, and there's a reason for that. It's a good one.
Robert Tisserand's book is considered by many to be the book on Essential Oil Safety.
It's a fabulous reference tool for anyone wanting to know more about essential oils in general, and essential oil safety in specific.
Essential Oils are pretty stable, but you need to take care how to store them.
Use common sense. If an oil smells bad or looks bad, don't use it.
Better safe than sorry.
Of course, you need to be careful to buy pure oils in the first place. Personally, I buy oils from several different sources.
Years ago, I started looking for a quality essential oils company that I could trust. After hours and hours of work, I ended up choosing the essential oils company mentioned in this post and have added Neal's Yard Remedies to the mix. I initially chose them for their skincare and personal care, but they have an amazing line of oils that are all produced sustainably.
A number of you have asked about organic essential oils – I am talking to other companies as well so that I can have more sources for my family and for all of you as well. Please stay tuned for that information.