I need a bit of chemistry to explain this, so bear with me.
The main difference between carrier oils and essential oils is: essential oils disappear fast, in a matter of hours. Carrier oils do not.
Why does that happen? Well, essential oils mostly contain small, light, volatile, organic molecules… Molecules like limonene, linalool, and eucalyptol. These molecules are volatile, meaning they can’t wait to escape the oil and get into the air. That’s why they disappear so fast.
Now, carrier oils like coconut oil and sunflower oil contain large, heavy, nonvolatile organic molecules… Molecules like fatty acids (e.g. linoleic acid and oleic acid) and vitamins. These molecules are nonvolatile, meaning they are too big to leave the oil on their own (they need a lot of heat to do so). So at normal room temperature, they do not disappear fast.
To see this better, I did a little experiment with two drops of sweet orange essential oil and tamanu oil. After a couple hours, the essential oil almost disappeared. But the carrier oil remained the same.
Without a doubt, the volatile molecules in the essential oil caused it to disappear (almost).
But this is not the only difference between the two oils.
Difference between carrier oils and essential oils #2
Smell is another important one.
The light, volatile organic molecules in essential oils are usually aromatic. That means they have a strong, unique smell. Meanwhile, carrier oils barely have a smell, if at all (there are a couple exceptions though).
Let me give you a couple examples.
Eucalyptol is the compound that gives eucalyptus essential oil its characteristic odor. And limonene is behind that orangey, lemony smell that you absolutely love.
Now, think of coconut oil. It has a beautiful, faint nutty scent. If you add eucalyptus essential oil to coconut oil, what happens? Of course, eucalyptus will dominate the blend.
Then, there is emu oil, a carrier oil made from emu (bird) fat that has an unpleasant “chicken fat” smell. I did say there were a couple smell exceptions to the rule. But you can easily use an essential oil to mask emu’s strong smell.
Difference between carrier oils and essential oils #3
Another difference is the chance of getting bacteria and mold growing in your oil. Yes, it can happen! If you leave your carrier oils in the shower and water gets in them, microbes can start growing and partying. If your oil gets very cloudy or has dark spots – it’s bacteria or mold.
It’s tough for bacteria and mold to grow in essential oils. That’s because a lot of the molecules like eucalyptol are strong antimicrobial agents. So no mold parties here!
I’ll end with this one. The extraction process used to get the oils are usually different, but there are many exceptions.
Essential oils are typically obtained from steam distillation, cold pressing or solvent extraction. But the first process is the most common.
For it, producers pass steam over plant material like lavender flowers and buds. The volatile molecules that are so quick to escape, leave the flowers and flow with the steam. When this is cooled, we get a water hydrosol and the essential oil, which floats on top, because oils are hydrophobic (they have a water phobia haha!).
Cold pressing does not use any heat or steam. Plant material like citrus peels are squeezed so much that the essential oil oozes out. Small amounts of nonvolatile molecules come out with the oil too. That’s why in my experiment the orange oil didn’t totally disappear after a couple hours.
Solvent extraction uses a chemical solvent (like hexane) to dissolve the volatile molecules. The solvent is then processed which separates the essential oil out.
Carrier oils are typically obtained from cold pressing. Steam distillation is never used to get carrier oils. And that right there is another difference between the two.
So that’s it. The difference between carrier oils and essential oils. Do you know any others? Share them with me in the comments below.
If you found this article helpful, then you should check out this one too: it explains what are essential oils, carrier oils and absolutes.