One of the most common question that buyer have in mind is about the expiry date of essential oils. There are many misconceptions about shelf life of essential oils. In this article we’ll try to understand the science behind the shelf life of essential oils and investigate the factors that affect the shelf life of essential oils.
Do Essential Oils Really Expire?
One of the most common myths about shelf life of essential oils that needs to be debunked is that pure and unadulterated essential oils don’t have an expiry date and can last lifetime.
That’s true but not completely. So, you might be wondering what the truth is. Well, generally unadulterated essential oils do not expire as they comprise antibacterial and antiviral characteristics and do not contain H2O. Hence, pure essential oils don’t grow mildew, mold, or yeast.
However, this is true until these essential oils are exposed to light, heat, oxygen or any other outside properties. As the pure oils come in contact with any such outside properties, they start changing.
Understanding the Science behind Shelf Life of Essential Oils
To understand this we need to first understand the chemistry background of essential oil molecules.
Essential oils are complex mixtures of various constituents. The rich therapeutic characteristics of essential oils come from active constituents like monoterpenes, sesquiterpenes, monoterpenoids, and sesquiterpenoids.
When monoterpenoids and sesquiterpenoids are exposed to air, they tend to undergo the following oxidation process.
What is Oxidation Process?
Oxidation may sound a simple word but it’s indeed a complex process. In simple terms it means to undergo or cause to undergo, a reaction in which electrons are lost to another species. Oxidation is also responsible for spoiling wine and turning it to vinegar when it is accidentally exposed to air during storage.
Now, you must be wondering that wouldn’t it transform an oil into something else? Well that’s the point. It won’t be completely correct to claim that essential oils don’t have an expiry or their shelf life is indefinite.
What Factors are Responsible for Degradation of Shelf Life of Essential Oils?
Degradation of essential oils shelf life takes place when they are exposed to one of these factors:
When oxygen molecules enter in bottle and reacts with some of the pre-existing constituents of essential oils, it may not only impact the medicinal properties of the oil, but may also turn it more hazardous (source). One of the common hazard is increased risk for sensitization.
Another culprits that might potentially degrade the essential oils is h. It causes the more volatile constituents to evaporate more quickly. Essential oils derived using CO2 extractions are more at risk of damage from heat than steam-distilled essential oils.
Exposure to light can also potentially damage the qualities of essential oils. This is why it’s recommended to use Amber colored bottles as they are best at keeping UV light out.
So, if Essential Oils expire what is Their Shelf Life?
The shelf life of essential oils varies depending upon the their profile and major constituents they contain. For example – essential oils like geranium Pelargonium graveolens (L’Her.) and grapefruit Citrus paradisi (Macfad.) are more prone to oxidation thus they have less shelf life in comparison to stable essential oils like immortelle Helichrysum italicum (Roth) and lavender Lavandula angustifolia (Mill) which have anticonvulsant properties of linalool
What Should I do to Increase Shelf Life of Essential Oils?
As we discussed in the article, the major factors that make essential oils go bad are oxyzen, heat and light. You can get rid of these outside circumstances by storing essential oils in a cool, dark place, in a full glass or food-grade aluminum bottle with a tight-fitting lid.