Do essential oils go bad?
Here is some info from Aromahead Institute, where I received my training/credential back in 2011.
Everything in nature has a season, and every organic substance has a shelf life. Essential oils are organic substances that naturally oxidize—that means their molecules lose electrons over time. And as the molecules within essential oils break down, their characteristics and properties change.
An oxidized essential oil may not be as potent as a fresh oil. It might even cause issues like skin irritation or sensitization, if used topically undiluted. If you were to compare an oxidized oil to a fresh one, you might find the oxidized oil’s aroma isn’t as pure or vibrant.
How can you stop essential oils from oxidizing and make them last? Let’s say you want to buy a bottle of lavender oil (Lavandula angustifolia). It’s shelf life is about 6 years. The company you’re purchasing from should share that information, and should know when that particular batch of lavender oil was distilled. If you can’t find the information clearly displayed on the website, contact the supplier and ask for the distillation date. Most reputable suppliers are happy to give you this info. (If they won’t share it, that likely means they either don’t know for sure, or the oil’s remaining shelf life is too short for it to last long.)
If the lavender oil was distilled 2 years ago and its shelf life is 6 years, that means there are 4 years left in its shelf life. If you buy that bottle of lavender, it will last 4 years on your shelf (assuming you store it properly—we’ll get into storing your oils in a moment!)
Not all oils have a shelf life of 6 years, like lavender. Different essential oils oxidize at different rates because they have different molecules. Some essential oils last 1-2 years, while others can last for over 8 years. (And some oils—like patchouli—can last even longer!)
The best thing you can do is buy top quality pure essential oils, and store them away from heat, oxygen and sunlight.
Some aromatherapists like to store their essential oils (and other aromatherapy products) in the fridge, even having a special “aromatherapy fridge” that isn’t used to store food. (Just be aware that if you do this, some oils—like rose—may crystallize in the cold. That’s natural. Just take them out of the fridge and let them return to room temperature before you want to use them.)
But you don’t have to keep your essential oils quite that cold. It’s enough to keep them in a cool, dark location, out of heat and light, in tinted glass bottles (the colored glass prevents light from getting through to the oil) that are tightly closed.
The same rules apply to any blends you make. Store them in a cool, dark location and keep the bottles closed. It helps to use tinted glass bottles, too—amber and cobalt blue are popular colors.
But don't despair if your essential oils are old...even if they are not the highest therapeutic concentration, the scents can still be incredibly effective and uplifting/relaxing/whatever! You can diffuse them, and use them in recipes where their therapeutic properties aren’t the main focus, like bath scenting, lotions, and natural cleaning.
