What are CO2 Extracts in the World of Aromatherapy?

A drop of oil can be essential

A drop of oil can be essential to wellbeing

When we talk about essential oils, it’s often an umbrella term for many different kinds of aromatic liquids.

Essential oils

These are usually water/steam distilled, and this is the most common way to date that oils are extracted. All the oils you would commonly buy today would be steam and water distilled and this process is simple, traditional and dates back through the past century.


These are usually made flowers or very delicate plants where a chemical extraction process is used  (see my article Absolutes? Not Absolutely)  but they resemble essential oils in viscosity and are used in the same way as essential oils. They tend to be more concentrated then essential oils.

Oleoresins and Resinoids 

These are highly concentrated liquid extracts that are a combination of resins and aromatic oils. The plants they come from have a high resin content so they fall into their own category. Once again they can be used in the same way as essential oils.

CO2 Extracts 

CO2 Extraction is also called Super-critical CO2 extraction and it produces a couple of plant products – extracts or selects, and totals.

A relative newcomer in the world of extraction, the name makes it sound bad but it’s not! There are lots of good things about this process and I’ll try to sum it up briefly and succinctly.

The extraction process uses carbon dioxide heated to a degree where it has both liquid and gaseous properties- this part is the super-critical part. It’s less hot them steam and water distillation so this is a bonus as it doesn’t change the plant materials as much.

It’s this liquid form that extracts the volatile plant material. Aromatic oils, resins and other cellular materials like pigments are extracted by the liquid CO2 which evaporates easily, leaving a substance that more closely resembles the plant.

CO2 extracts more closely aromatically resemble the whole plant, whereas essential oils are specifically the volatile oil component of the plant.

CO2 extracts may be better scent wise, or less attractive. It depends on the plant.


nutmeg –  there are quite a few spice CO2 extracts

CO2 extracts that are now available are –

ambrette, cardamom, cinnamon, coriander, clove, nutmeg, caraway, fennel, ginger

sea buckthorn


cocoa, coffee, vanilla


evening primrose, rosehip

chamomile, champaka, ginger lily, jasmine, juniper, linden blossom, patchouli

arnica, calendula, lavender, hops, St Johns wort,

angelica root, orris root, kava

agarwood, frankincense, galbanum, myrrh, spikenard

the amazing vanilla pod

the amazing vanilla pod

I don’t use CO2 extracts extensively in my practice yet, as many of the extracts are semi-solid and aren’t easy to work with. It seems some of the extracts are better suited to using in creams and lotions.  I move more into the area of natural perfumery I know I’ll use some of the extractsmore often. I haven’t actually spent the time looking at the analysis of each oil, which will indicate the therapeutic property of the “oil”.

According to Nature’s Gift, “totals” are a secondary product of the CO2 process:

“are usually thick and pasty due to the beneficial fats, resins and waxes they contain that come from the plant material itself. These totals are soluble in essential oils and vegetable oils.

….These potent extracts are wonderful for cosmetics and pharmaceuticals. The Calendulas extract, for example, in a dosage of 2 grams extract to 1000 grams ointment is effective for it’s anti-inflammatory and anti-microbial activity.”

None of my suppliers in Sydney provide these “totals” and I don’t have first hand knowledge of how they work – but it sounds interesting!

Good luck with the CO2 extracts!

copyright suzannerbanks 2013

Amber – A Complicated Story

Baltic Amber - from a few different species in the Mediteranean

Baltic Amber – from a few different tree species in the Mediterranean

The other day my client asked me about amber oil. I told her that I’d researched it years ago and that it didn’t seem to be straight forward – and that I’d forgotten everything too, and that I never used it. She had a little sample of resin and it did smell beautiful. So what is her sample, really?

It seems there’s a few stories floating around out there which include –

Ambergris – sperm whale vomit or poo

Liquidambar orientalis – the sap from the tree

Baltic amber or succinite – the hard crystals we know that are used for jewelly


Pinus succinefera fossil – fossilised sap

Here’s what I can gather about the truth of Amber oil.


ambergris - I think

ambergris – I think

Ah yes the lovely scent of sperm whale poo and vomit. The ambergris seems to be a secretion in the digestive system of the whale to protect it’s gut from spikey cuttlefish. It is excreted with fecal matter, or regurgitated if the amount is too large to pass.The story goes that this intriguing substance was found around the Atlantic Ocean along the shorelines of many countries including Australia and NZ, Japan, South Africa, The Maldives and other areas in the world. Apparently as it aged, the scent changed to a sweet balsamic, earthy odour and was therefore grabbed and distilled by perfumers to use as a fixative in scents. It can still be found today and is worth a lot of money! If you have a perfume with that listed it would be synthetic. All perfume is synthetic anyway, so don’t panic, there’s no vomit in your fragrance.

Liquidambar orientalis

This seems to have more credit in the ‘amber stakes’. The name also has “amber” in it so there’s a bit of a hint (or coincidence). This gorgeous tree is planted all over Sydney and I believe it originates from the Mediterranean region, particularly in Turkey. The trees are referred to generally as “sweet gum” and these forests in Turkey (according to wikipedia) are under threat due to dam building and clearing for agriculture. This oil is also produced in India, and the tree is also native to India.

In English, this oil is known under several names, shortly as Storax to include all sweetgum oils, or as Styrax Levant, Asiatic Storax, Balsam Storax, Liquid Storax, Oriental Sweetgum Oil, or Turkish Sweetgum Oil. …. it is used externally in traditional medicine for abrasions, anxiety, bronchitis, catarrh, coughs, cuts, ringworm, scabies, stress-related conditions and wounds. It is a different product than the benzoin resin produced from tropical trees in the genus Styrax.


I have never used this oil but now I’m a bit desperate for it. It sounds bloody gorgeous. We had a beautiful liquid amber tree in our backyard when I was growing up. I did a school project on it – if I’d only know it contained a medicinal, scented secret!

As with Frankincense and Myrrh, the tree is tapped and the sap collected. To produce the oil, the resin then undergoes steam distillation.

Baltic Amber

Baltic Amber with a fossilised insect

Baltic Amber with a fossilised insect

Baltic amber refers to fossilised tree resin from a variety of conifers living around the Scandinavian countires and the Baltic region. The Pinus succinefera is one of these trees and this stone is sometimes referred to as succinite (and also because it contains succinic acid).The Baltic region contains most of the world’s supply of amber which could be between 40 to 60 million years old! Oh dear should we really be digging this up?

So this leads us to the claims that this stone can produce a resin, then an oil.

Pinus succinefera – fossil

Pinus succinefera - the fossil - also possibly Baltic amber

Pinus succinefera – the fossil – also possibly Baltic amber

This fossil relates to the Baltic Amber above. But can the stone produce this oil? How is it extracted? Dry distillation could be used, whereby a solid is heated to produce gasses and materials which are then condensed and collected. This is a fossilized resin so I’m wondering if the claims that the oil is Pinus succinefera – fossil, are false.

There are stories of this stone and resin/oil being used by the Romans and Greeks to use medicinally and in rituals. Did they have dry distillation techniques or were they collecting sap and distilling it?

It’s all very interesting and if anyone has anything to add or can clarify any of these claims I’d be grateful. Just leave a comment.

My money is on Liquidamber orientalis but none of my trusted suppliers sell this. Hmmmmm.


copyright suzannerbanks 2013

Absolutes? Not Absolutely

the fragrant jasmine blossom

the fragrant jasmine blossom can be steam distilled or an absolute

Straight from Wikipedia I thought this was a good explanation of an absolute:

Used in perfumery and aromatherapy, absolutes are similar to essential oils. They are concentrated, highly-aromatic, oily mixtures extracted from plants. Whereas essential oils can typically be produced through steam distillation, absolutes require the use of solvent extraction techniques or more traditionally, through enfleurage.

So basically absolutes are essential oils derived from solvent extraction or enfleurage.

Enfleurage is a term to describe the extraction process. It can be cold or hot and unfortunately animal fats are used. Right off the bat that turns me off. I’m a vegetarian and have been for nearly 30 years. I don’t wear leather and try to be mindful of everything I buy or consume in my life. I don’t buy absolutes for this reason. This method was created hundreds of years ago specifically for perfumery. I really can’t think of anything worse than mixing botanical substances in hot tallow to extract a scent. Blah. And if you didn’t know –  hoofs and other materials from the bodies of horses, cows and pigs are boiled up to make things like tallow and gelatine.

I’m not even sure if this method is used in commercial production at all.

Adorable cow and calf

Adorable cow and calf

In both instances, once the fat is saturated with fragrance, it is then called the “enfleurage pomade”. The enfleurage pomade was either sold as it was, or it could be further washed or soaked in ethyl alcohol to draw the fragrant molecules into the alcohol. The alcohol is then separated from the fat and allowed to evaporate, leaving behind the absolute of the botanical matter. The spent fat is usually used to make soaps since it is still relatively fragrant.


Then there’s solvent extraction which usually uses some type of chemical to extract the scent. Often hexane is used which some people claim is safe, but I’m not quite sure about that. It’s usually alcohol that’s used and I suppose it’s relatively harmless. When this method is used a “concrete” is formed, which is then soaked in alcohol. When the alcohol evaporates, the absolute remains.

the structure of hexane - from wikipedia

the structure of hexane – from wikipedia

Gasoline has a high amount of hexane but I’m not sure about the origin of the hexane that used in absolute production. I’m unsure if it would come from petrol, or if it would be synthesized in a lab and sold by chemical companies. At any rate, I’d prefer to buy a steam distilled oil, or an oil produced by CO2 extraction which is also called Super Critical extraction. That sounds a bit wrong but the CO2 method seems to be an environmentally friendly way to extract aromatic compounds. I’ll do a separate article on that.



Oils that you may find as an absolute –





Lotus – pink and white






Tomato leaf

Violet leaf



And there are probably lots more too. It’s totally up to you as to what oils you buy but I prefer to choose oils that have a more simple extraction method.

Your thoughts?

oakmoss - is this sustainably produced?

oakmoss – is this sustainably produced?


copyright suzannerbanks 2013