Carrier Oil Shelf Life
Updated: Oct 9, 2020
Carrier or base oils are the most common foundation used in aromatherapy blending.
Carrier or base oils are the optimum environments to blend essential oils because of their “fixed nature,” meaning they are stable and have a slow evaporation rate. Essential oils are known as “volatile,” which means they have a high evaporation rate.
The carrier oils used in therapeutic aromatherapy blending are extracted from vegetables, seeds, and nuts. They are rich in nutrients, vitamins, and are soothing, nourishing, and restorative to the skin.
Using the highest quality of carrier oils, that are organic, cold-pressed, and unfiltered, makes a significant difference in the therapeutic quality and absorption: for this reason, no animal, mineral, or synthetic oils are used to formulate therapeutic essential oil blends.
Two amazing benefits for using carrier oils in an aromatherapy blend: 1) They allow for prolonged absorption of the essential oils. 2) Organic, unrefined carrier oils also have the added benefit of many vitamins and minerals that are not present in essential oils.
Carrier Oil Shelf Life
The unsaturated fats contained in carrier oils have a carbon-carbon double bond in their structure, these bonds can be broken by oxygen in the air, and the process is called oxidation. Most vegetable oils will oxidize over time and eventually become rancid. When they age, these oils “lose their vitamins and can develop potentially toxic compounds”, states Eric Decker, the head of the Department of Food Science at the University of Massachusetts Amherst.
When oil becomes rancid, the aroma and flavor will change over time. Rancid oils will have a sharp, bitter, and unpleasant aroma. It is good to smell each of the carrier oils when you first purchase them, and then each time you use them. While rancid oil may smell and taste unpleasant, it will not usually make you sick in the short term. However, over the long-term rancid oil does contain free radicals that might increase your risk of developing diseases.
If you forget to put the cap on a bottle of oil, such as sesame or olive oil, the oil will be exposed to oxygen. In this case, "Oxygen comes bumbling along and hits a carbon-carbon double bond," said John Malin, a retired associate professor of chemistry at the University of Missouri. "The oxygen attacks that double bond and forms a carbon-oxygen bond."
This carbon-oxygen bond can lead to several chemical alterations, including aldehyde, ketone, or carboxylic acid. Some of these chemicals have rancid odors and tastes.
The list below shows the typical shelf life for many carrier oils used in aromatherapy.
To extend the shelf life, store in dark glass bottles and out of the heat, preferably refrigerated. When receiving new shipments of oils, You can add the date on the label when you receive each oil to help you keep track of the shelf life. To avoid contamination of the oils, use pump bottles and dispensing tools, like pipettes and funnels, rather than your fingers.
6 Months: Borage (Borago officinalis)
Rosehip (Rosa rubiginosa/Rosa mosqueta)
6 Months - 1 Year: Evening Primrose (Oenothera biennis) Tamanu (Calophyllum inophyllum)
1 Year: Almond, sweet (Prunus dulcis)
Apricot Kernel (Prunus dulcis) Arnica (Arnica montana) Avocado (Persea americana) Calendula (Calendula officinalis) Carrot Seed (Daucus carota) Grapeseed (Vitis vinifera) Macadamia Nut (Macadamia integrifolia) Seabuckthorn Berry (Hippophae rhamnoides) Sesame (Sesamum indicum) St. John's Wort (Hypericum perforatum) Sunflower (Helianthus annuus) Walnut (Juglans regia) Wheatgerm (Triticum spp.)
1- 2 Years: Aloe Vera (Aloe barbadensis) Argan (Argania spinosa) Camellia Seed (Camellia oleifera)
2 Years: Olive (Olea europaea)