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CO2 Extraction: The Superior Method

CO2 Extraction: The Superior Method

March 04, 2019

There is significant debate regarding the best extraction method for hemp and cannabinoids. Encore Life utilizes CO2 extraction because it is non-toxic, safe, and sustainable compared to other methods.


What is CO2 Extraction?

Carbon dioxide (CO2) is a natural and innocuous compound used in many food products (e.g., carbonated beverages). Using a laboratory-grade compressor, CO2 can be pressurized and heated until it reaches a supercritical state (88° F at 73.9 bar), expanding like a gas with the density of a liquid. It then acts as a solvent and strips cannabidiol (CBD), cannabinoids, terpenes, and essential oils from hemp plant material. The pressure is lowered and medicinal phytochemicals separate from the CO2 into a collection chamber as concentrate [1,2].

The relatively low temperature required for supercritical CO2 allows preservation of volatile but beneficial compounds like terpenes. Adjusting pressure, temperature, and time modulates the process until an ideal product is achieved. CO2 is a renewable resource that can be recycled for continued use.  CO2 extraction is an environmentally-friendly method to deliver potent concentrates that are free of toxins and completely safe for consumption [1-3].


Other Cannabinoid Extraction Methods

The most common commercial alternative to CO2 extraction is hydrocarbon solvent extraction. Typical solvents include naphtha, petroleum ether, and butane. This method involves immersing plant materials into the solvent until beneficial compounds have been stripped from the plant. Heat is applied to the enriched solvent until it evaporates and leaves the concentrated plant compounds [1,4].

Romano & Hazekamp (2013) found that this method leaves residual solvents in the final concentrate. Solvents are flammable, cancer-causing, and neurotoxic. The procedure dissipates most terpenes [4]. Although this method is cheap and relatively easy, it regularly causes explosions and burns [5]. The solvents are toxic contaminants [2].

Ethanol extraction is a commercial solvent that avoids the toxic byproducts of hydrocarbon solvents. However, ethanol removes water-soluble molecules like chlorophyll and other unwanted chemicals from the plants [6]. It shares the flammable characteristics of hydrocarbon solvents. A Yale University publication suggests that ethanol production has negative environmental consequences [7].


CO2 Extraction for Purity and Potency

An American Chemical Society presentation in 2014 considered CO2 extraction the “safest extraction option,” for cannabinoids because it is “non-toxic, non-flammable, environmentally neutral,” and maintains a “terpene-rich extract profile.”[8] Presenters at the 107th American Oil Chemists’ Society Annual Meeting and Expo referred to it as the “method of choice” for cannabinoid extraction due to “favorable conditions employed and its environment-benign nature and consumer compatibility.”[9]

Cost and convenience do not supersede environmental impact and health. CO2 extraction delivers a purer and more potent product. Encore Life advocates CO2 extraction as the superior method.



  1. Orens, Adam, et al. (2015). Marijuana Equivalency in Portion and Dosage: An Assessment of Physical and Pharmacokinetic Relationships in Marijuana Production and Consumption in Colorado. Colorado Department of Revenue, 12.
  2. Stahl, E., et al. (1980). Extraction of Seed Oils with Liquid and Supercritical Carbon Dioxide. Journal of Agricultural and Food Chemistry,28(6), 1153-1157. doi:10.1021/jf60232a023
  3. Cannabis Oil Extraction Methods (2019). Project CBD. Retrieved from
  4. Romano, Luigi L & Hazekamp, Arno (2013). Cannabis Oil: Chemical Evaluation of an Upcoming Cannabis-Based Medicine. Cannabinoids, 1(1):1-11.
  5. Romanowski, K. S., et al. (2017). Butane Hash Oil Burns. Journal of Burn Care & Research,38(1), 1st ser., 165-171. doi:10.1097/bcr.0000000000000334
  6. Storey, R. (1980). Erratum: The Advantages of Chlorophyll Extraction with Alcohol. The American Biology Teacher,42(3):180-181. doi:10.2307/4446978
  7. Runge, C. F. (2016). The Case Against More Ethanol: It’s Simply Bad for Environment. Yale Environment 360. Retrieved from
  8. Hudalla, Christopher J. (2014). Cannabis Chemistry 201. ACS Webinar [Powerpoint slides]. Retrieved from
  9. King, J.W. (2016). Extraction of Cannabis and Hemp Using Sub- and Supercritical Fluids. 107th AOCS Annual Meeting & Expo: Cannabis Extraction and Analytics Interest Area Technical Program Abstracts.


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