Cannabis Extractions: BHO (Butane Hash Oil)
BHO or Butane Hash Oil is one of the most potent forms of cannabis extracts, allowing the consumer to experience the full spectrum of flavor and experience the effects that each strain has to offer in a concentrated form because of its potency and terpene retention. However BHO, if not manufactured correctly, can be a potential health risk for consumers, due to the potential of directly inhaling residual butane, as well as any residual pesticides and or nutrients left in the final product. Working with BHO extractions can be a safety hazard for lab technicians as well, if not manufactured with proper equipment and safety protocols set in place, because of how flammable butane is. In Nevada, all cannabis products are tested for quality assurance prior to being sold, ensuring that they are safe for human consumption. For solvent-based extractions, such as butane hash oil, there is a residual solvent tolerance limit that production facilities who manufacture cannabis concentrates, cannot exceed. BHO has to remain under 500ppm (parts per million) of butane, anything over that is considered unsafe for human consumption by the state of Nevada and cannot be sold at any dispensary. A part per million or one ppm is equivalent to 1 milligram. The process of manufacturing any solvent based cannabis extract should only be done by trained professionals in state-approved production labs.
What is Butane?
Butane is a highly flammable, colorless, and odorless gas that is used as a non-polar chemical solvent in cannabis extractions. Non-polar solvents like butane dissolve non-polar compounds, such as oils and lipids, from the plant material, and doesn't extract water-soluble compounds like chlorophyll. There are many chemical extraction solvents that are used to extract cannabinoids and terpenes from the raw plant material to produce a more concentrated form of cannabis. Butane in its liquid form is used to dissolve the oils and lipids that make up the trichome heads, from the plant material. The butane is then purged or evaporated in a vacuum oven or vacuum pump, to ensure you are left with as little residual solvent as possible. Butane requires less pressure to stay in its liquid form, which makes it very effective at extracting oils, while other chemical solvents, such as supercritical CO2, require a minimum of 800 psi and can go all the way up to 10,000 psi in some extraction processes. For this reason, proper equipment and training are recommended to ensure the safety of the manufacturer and consumer. Closed loop systems are the industry standard when it comes to manufacturing butane hash oil, these systems are able to keep the chemical solvent sealed and under pressure as it passes through the plant material extracting valuable cannabinoids and terpenes in the safest and most efficient way possible.
General Extraction Method
A vessel or column is filled with cannabis (trim or flower), a filter is then attached to prevent any plant material from entering the final product.
Liquid butane is then passed through the plant material to extract the cannabinoids from the plant matter.
The cannabinoid mixed liquid butane is then collected in another vessel where it is then left to purge in a vacuum oven to ensure the extract is left with as little residual chemical solvent as possible.
Butane hash oil concentrates come in many different textures and forms such as wax, shatter, budder, and sap. The factors that determine the final texture of the BHO concentrate all depend on the purging techniques, genetics processed, post-extraction manipulation methods, and terpene content. These concentrates are known to be very potent and packed with a rich amount of cannabinoids and terpenes. However, the question remains... What health risks are attributed to direct inhalation of small amounts of butane? Especially in states that don't regulate proper testing protocols to ensure the safety of consumers and medical patients who use cannabis as a daily medicine, how do they know if the products they are using are safe? It's not recommended for anyone to attempt to manufacture BHO concentrates on their own and without proper training to ensure the safety of both the consumer and producer.