Hash and Oil Extraction Information
Follow this link to download a recent PDF document about research into extraction methods such as the Rick Simpson Oil method, Ethanol (alcohol) and Olive Oil extraction, contaminants, safety, and active ingredient content (cannabinoids, terpenes, flavonoids) - Romano-Hazekamp Cannabis Oil Cannabinoids 2013
by Dr. Arno Hazekamp
Concentrated cannabis extracts, also known as Cannabis oils because of their sticky and viscous appearance, are increasingly mentioned by self-medicating patients as a cure for cancer. In general, preparation methods for Cannabis oil are relatively simple and do not require particular instruments. The purpose of the extraction, often followed by a solvent evaporation step, is to make cannabinoids and other beneficial components such as terpenes available in a highly concentrated form. Cannabis oil is usually taken orally, by ingesting a small number of drops several times a day. Please find here some information on the question whether cannabis can cure cancer.
Various methods have been described for the preparation of Cannabis oil. The most popular method, as described by former (skin)cancer patient Rick Simpson from Canada, suggests the use of naphtha or petroleum ether as a solvent for the extraction. Following the success of Simpson oil, a number of related recipes have sprung up, emphasizing small but significant changes to the original recipe. Examples include focusing on safer solvents such as ethanol, or preventing exposure to organic solvents altogether, by using olive oil.
In general, petroleum-ether and naphtha refer to very similar products, even though different names may be used around the world; e.g. in some countries naphtha is equivalent to diesel or kerosene fuel. Both solvents are a mixture of petroleum hydrocarbons (PHCs), often available in a wide range of qualities. All the solvent components should be considered harmful and flammable, and some of them, such as hexane and benzene, may be neurotoxic. Both naphtha and petroleum-ether are considered potential cancer hazards according to their manufacturers. Moreover, products sold as naphtha may contain added impurities (e.g. Coleman® fuel) which may have harmful properties of their own.
Although Cannabis oils are usually concentrated by evaporating the solvents that were used for extraction, this does not completely eliminate residual solvents. As a result of sample viscosity, the more concentrated an extract becomes, the more difficult it will be to remove the residual solvent from it. In such a case, applying more heat will increase solvent evaporation, but simultaneously more beneficial components (such as cannabinoids or terpenes) may be lost as well. The use of non-toxic solvents should therefore always be advised, so that potential residues are not harmful to health.
Recently, an analytical study was performed to compare several generally used preparation methods on the basis of cannabinoids, terpenes, and residual solvent components. Solvents tested included ethanol, naphtha, petroleum-ether, and olive oil. Based on this study, the following recommendations can be made:
Dr Arno Hazekamp is a phytochemical researcher at the Department of Plant Metabolomics of Leiden University, The Netherlands. He also coordinates the R&D program at Bedrocan BV. This FAQ was posted on the invaluable IACM website, where you’ll also find a relevant paper by Luigi Romano and Hazekamp, Cannabis Oil: chemical evaluation of an upcoming cannabis-based medicine.