folded mean when it comes to essential oils? Folded oils tend to be citrus based oils - orange, grapefruit, lime, lemon - and we see them as 5X or 10X folded.
Folded essential oils are those that have been further distilled and concentrated to create a more concentrated, and usually stronger smelling, essential oil. The oils should have a longer shelf life because some of the terpenes that contribute to oxidation of the oil have been removed, and they should be safer to use in leave in products thanks to the removal of those same terpenes.
furanocoumarins or furocoumarins, which can make the oils photosensitizing. Removal of these compounds can make the oil less likely to be phototoxic when used in leave in products. (Notice I said the word "likely"...)
A phototoxic ingredient "is a chemical compound which becomes toxic when exposed to light. Some medicines: tetracycline antibiotics, sulfonamides, amiodarone, quinolones. Many cold pressed citrus essential oils such as bergamot oil. Some plant juices: parsley and Giant hogweed. Others: psoralen." (Wikipedia). You'll notice the word "cold pressed" before the word citrus. This is because the cold pressed versions of essential oils contain more furocoumarins, which is why they are folded to ensure there are fewer photosensitizing compounds.
Can we use folded oils in leave on products and be guaranteed the product users won't be subjected to phototoxicity? No, and here's the problem with essential oils in general....
I've mentioned before that mineral oil is used a lot in commercial products because it's predictable. We know that when we see something like "light mineral oil" (I'm making up this name for the purposes of this post) that it has a certain characteristics. When we see something like sunflower oil, we know some general things, but it is affected by the terroir - the place it was grown, the climate, the way it was processed, and so on - so the characteristics are not the same with every bottle. This means it could change the viscosity of our lotion, the amount of linoleic acid, and so on. It's the same thing with essential oils. Although we know that orange oil contains orange essential oil, each bottle could be different with differing levels of terpenes or other compounds depending upon the climate, growing temperature, processing, and so on. So when I see something called 10x orange oil, it means that the oil has been concentrated to increase the fragrance and remove some of the photosensitizing compounds. But the 10x orange oil from one company might be different than the 10x orange oil from another company thanks to different manufacturers and different places they've been grown.
As a rule, I don't put citrus based essential oils in anything that won't be completely rinsed out. That means I reserve them for my body wash and shampoo for the most part. It does suck because the Creamsicle lip balm I made with vanilla and orange essential oil tasted amazing...
If you're using folded essential oils, the risk is lower, so I leave it to you to make your own decisions based on the information you have from your supplier and past experience. If you're new to essential oils, please be really careful when using orange, lime, lemon, and so on...the goal is to make the end user happy, not burn them when they're out in the sun for a few hours.
I know some of you are considering writing to me to say that you have used citrus based essential oils safely and think my comments are insane. To you I say, fantastic! I'm glad you can use them well. But please consider this story...A very enthusiastic young woman posted her lip balm recipe - lime juice, sugar, and Vaseline - on a very large crafting forum with the comment, "I guess I sell lip balm now!" I got in trouble from the moderator for telling her this was a very bad idea, so I abandoned that forum, spent more time at the Dish, and started up this blog. There are people out there who think this kind of recipe is a good idea to make and to sell. If you have successfully used non-folded citrus based essential oils in your products, to you I say, "Kudos!" But please remember that your success isn't necessarily what others will experience!
Wow, how did we go from information to a lecture? Sorry about that! Join me tomorrow for some ideas on how to use orange oil in our products!
I encourage you to read my article from Handmade Magazine for more information on citrus essential oils as I've learned a lot more since I wrote this post! The quick summary? Orange and yuzu are not phototoxic!