How Hemp-Derived Intoxicants are Made
Cannabinoids are a class of diverse chemical compounds that act on receptors which are part of the endocannabinoid system, found in cells that alter neurotransmitters released in the brain. Some are considered intoxicating such as delta-9 tetrahydrocannabinol (THC) commonly associated with marijuana, others such as cannabidiol (CBD) are not psychoactive.
Cannabinoids can come from several sources, including the human body which produces them in small amounts, and they are produced naturally in the Cannabis sativa L. plant which includes both hemp and marijuana varieties. Finally, they can be synthesized in a lab out of a wide variety of other chemicals.
Following changes to the definition of hemp in the 2018 Farm Bill, hemp plant material along with derivatives of hemp including constituent cannabinoids were removed from the Controlled Substances Act. Hemp does not naturally contain intoxicating cannabinoids in significant quantities. However, it is possible to chemically convert non-intoxicating CBD into an intoxicant form such as delta-9 THC and delta8-THC among many others. This change in the law along with available conversion techniques set conditions for the creation of hemp-derived intoxicants in the marketplace. This summary looks at the chemical conversion process that takes place to alter CBD into an intoxicating cannabinoid.
The production process involves extracting CBD from the hemp plant, purifying it, converting it into one or more intoxicating compounds through chemical reactions and potentially purifying the resulting compound.
CBD is first extracted from the hemp plant using various methods including CO2 extraction, ethanol extraction, or other solvent-based methods, similar to methods used across various industries to isolate specific compounds from a natural source. For instance, CO2 extraction is used in the coffee industry to decaffeinate coffee beans by selectively removing caffeine while leaving the flavor compounds found in coffee largely intact. CO2 is brought to a supercritical state, meaning it has properties of both a liquid and a gas, which allows it to act as a solvent to dissolve and extract cannabinoids and terpenes efficiently without leaving behind harmful residues.
Similarly, ethanol extraction is used in the vanilla extract industry to draw out vanillin and other flavor compounds from vanilla beans by soaking them in ethanol. In the hemp industry, plant material is similarly soaked in ethanol to extract cannabinoids, and ethanol is evaporated from the material, leaving behind CBD oil. Finally, other solvents such as butane or hexane can be used to extract CBD, which can be more hazardous and require careful purging to remove all traces of the solvents from the final product.
Irrespective of the technique, the goal is to isolate the desired compounds from the raw material without altering them chemically and while removing as much of the unwanted material as possible. Purity of the final product is crucial, and this is achieved through careful control of temperature, pressure, and other conditions during the extraction process.
Purification is a critical step in many industrial processes, where the objective is to isolate a desired substance from contaminants and byproducts. This step often follows initial extraction, refining the product to the required level of purity for its intended use. Several techniques can be used for purification of hemp extracts, including winterization which involves mixing the extract with alcohol and subjecting it to cold temperatures, which causes these impurities to solidify and separate from the mixture – common in biodiesel production, which removes saturated fats that can cause the fuel to become cloudy at lower temperatures. This process ensures that biodiesel remains liquid and functions properly in all weather conditions.
Distillation is another purification technique which can be used which takes advantage of the different boiling points of compounds. Distillation is the well-known process in the production of alcoholic beverages, which heats fermented liquid to a temperature that vaporizes the alcohol (which has a lower boiling point) but not most of the water. The alcohol vapor is then condensed back into liquid form, resulting in a higher concentration of alcohol.
Once extracted and purified, the conversion process can begin. The conversion of CBD to delta-9 THC or delta-8 THC other intoxicant is achieved through a process called isomerization. This process involves the rearrangement of the molecules within CBD to form some form of THC. CBD is subjected to an acid-catalyzed reaction, often using sulfuric, hydrochloric, or phosphoric acid to initiate and drive the process. This process is called isomerization, and is conducted under controlled temperature and time conditions. The result is a new molecule, which could be delta-8 THC, delta-9 THC or many others.
The result is a mixture that contains many chemicals including the chemicl reactants, by-products , unreacted CBD, and the new cannabinoids that were produced. Based on the techniques used, it is likely that the mixture contains an array of different forms of THC, rather than a single isolate, and the mixture needs to be purified.
As with the initial extraction to obtain CBD from hemp plant material, distillation can also be used to purify the resulting intoxicating compound. As mentioned, distillation exploits the different boiling points of the substances in the mixture to separate them.
Another purification technique, chromatography,can be used which involves passing the mixture through a medium (called the stationary phase) that separates compounds based on their different chemical properties, such as polarity or size.For THC porducts, all three are used, with varying degrees of success.
It should be noted that these defined processes (i.e. extraction, purification and chemical synthesis are those expected when conducted by trained professionals. It is unlikely, that such actions are performed in their entirety by unskilled people attempting to circumvent the intentions of the Farm Bill. As a result, the resulting material created is difficult to predict
Finally, the product should be tested to analyze its final makeup, ensuring the substance is at the desired purity, concentration, and that no harmful substances remain. Potency testing determines the exact concentration of one or more intoxicants. Residual solvents testing looks for solvents left behind from the extraction or purification process, which could include CO2, ethanol, or hydrocarbons which could be harmful above certain levels. Pesticide testing is essential if the starting material (hemp plant material) was treated with pesticides to ensure that these do not remain in the final product. Other tests include heavy metals testing, as hemp plants readily absorb heavy metals from the soil, along with testing for microbiological contaminants such as microorganisms like bacteria or fungi. Finally, because acids are used in the isomerization process, manufacturers should also include acid residue testing