Carbon dioxide (CO2) is a supercritical fluid, meaning it converts into a liquid form when pressurized. At the same time, it is a pure chemical substance that occurs naturally and leaves behind no residues.
Accordingly, the Supercritical CO2 extraction method (aka CO2 extraction) can help ensure cannabis concentrates are pure, making it a good option for patients in search of a natural form of cannabis oil.
Supercritical CO2 Extraction Is Safe, Effective
Supercritical CO2 extraction is already a standard extraction method for the food, dry cleaning and herbal supplement industries. It is a common food additive as well.
In fact, CO2 is used to produce carbonated soft drinks, in the removal of caffeine from coffee beans in order to make decaffeinated coffee, as an environmentally friendly solvent for dry cleaning, and as an extraction solvent when producing essential oils. Supercritical CO2 is also common when pesticides and metals are extracted from agricultural crops.
“The CO2 extraction process allows compounds to be extracted with little damage and low toxicity.”
The CO2 extraction process allows compounds to be extracted with little damage and low toxicity; it utilizes a high pressure vessel containing cannabis.
Supercritical CO2 is inserted into the vessel, and pumped through a filter where it is separated from the plant matter once the pressure is released. Next, the supercritical CO2 evaporates and is dissolved into the cannabinoids.
Popular Alternatives To Supercritical CO2 Extraction
Butane extraction is one popular alternative method to CO2 extraction in the cannabis industry. However, James Slatic points out that butane can “potentially leave heavy metals behind in the finished product.”
We’ve discussed this topic in the past (see: “The Comprehensive Guide to Dabbing & Cannabis Concentrates”), and it’s important to note that properly-made BHO is generally considered safe. Of course, product that has not been purged properly may be a completely different story, which is why I believe all concentrates should be lab-tested for safety before being distributed to patients.
“When the solvent (CO2) is pushed through the plant matter at such a high pressure, it can separate the matter precisely, which allows us to isolate only the purest essence.” – James Slatic
Nonetheless, James Slatic, believes that supercritical CO2 extraction offers substantial benefits over the other options available.
“When the solvent (CO2) is pushed through the plant matter at such a high pressure, it can separate the matter precisely, which allows us to isolate only the purest essence,” he explains.
Slatic goes on to say that the fact that CO2 is a pure, naturally occurring compound is “its biggest advantage over all other solvents used for plant extraction.”
There are rumors of an innovative extraction method being tested that does not use chemical solvents. Sytze Elzinga, a knowledge leader on extraction methods from The Werc Shop, explained that the new solventless extraction method “allows for the production of highly purified concentrates.”
Explaining further, Elzinga says: “These methods use sequences of different pressures and temperatures to create a golden resin without the use of chemical solvents.”
However, it should be noted that the solventless extraction method described by Elzinga has been criticized by the cannabis community for a few reasons, including the flavor of the extracts it produces.