In this post:
- What is Hydrocarbon Extraction?
- Is it the Best Method?
- How is Hydrocarbon Different from Solvent-Less Extraction?
- How is It Different from CO2 Extraction?
- Is It Safe to Ingest Cannabis With Hydrocarbon Solvents?
- What are the Potential Dangers?
Propane and butane sound like volatile compounds you never want to ingest. In fact, if you knew a cannabis extract contained these hydrocarbons, you might opt for a "cleaner" product instead. But the truth about hydrocarbon extraction lies somewhere between understandable skepticism and the reality that propane and butane are quite safe at low levels.
Florida's lawmakers agree, which is why the Office of Medical Marijuana Use (OMMU) recently added Hydrocarbons to its list of allowable solvents for low-THC and Medical Marijuana extraction in a draft rule.
You might still be suspicious or think other extraction methods are superior. We had our share of questions too. So we reached out to Dan Lavarini, the Chief Scientific Officer at Coachella Manufacturing in California.
A former aircraft engineer, Dan has been extracting cannabis with hydrocarbons since the early days of glass tubes and butane cans. Let's hear it, Dan.
First of All, What is Hydrocarbon Extraction?
In a nutshell, hydrocarbon extraction is a method to extract cannabinoids and terpenes from cannabis plants using hydrocarbons such as N-butane, isobutane, propane, pentane, and heptane. For the most part, we use butane and propane only.
What's the Process of Hydrocarbon Extraction?
We like to start with frozen cannabis material, cured (dried) or fresh, which we pack in columns and connect to our extraction machine–specifically a collection tank. Throughout the process, we utilize heavy-duty chillers to keep the solvent between -80 degrees Celsius and -100 degrees Celsius when needed. After setup, we flood the plant-material column with the hydrocarbon solvents until it's full.
Then we turn the upper valve off and open the bottom valve to move all the cannabinoid-rich solvents into the collection vessel. Once we move the solvent and oils, we heat the mixture to a boil, converting the solvent from a liquid to a gas.
We then force the resultant gas back into the solvent tank and get it cold enough to re-condense it back into a liquid. As that happens, the oil solvent mixture becomes thicker and thicker until we only have a trace amount of residual solvent left. From there, we pour the solution out of the machine and begin producing the end product– shatter, butter, sugar, diamonds, or vape oil, for example.
Is Hydrocarbon Extraction the Best Method for All Cannabis Products?
Today we consider two types of extraction to be the most effective at producing the absolute highest-quality product. One extraction type is solvent-less, and the other is hydrocarbon extraction. We prefer hydrocarbon solvents because we can extract more terpenes and preserve the flavor better at a more affordable cost than solvent-less.
With hydrocarbon extraction, propane and butane can quickly liquify cannabis compounds into themselves and carry them away in a very gentle and cold manner. We extract at near cryo-temperatures, close to -100 degrees Celsius, which helps preserve the plant's integrity.
I would go so far as to say hydrocarbon is our preferred extraction method for producing cannabis products. Why? Hydrocarbon extraction preserves the plant's broad spectrum of compounds, ensuring consumers and patients get the most therapeutic value while also removing undesirables like chlorophyll, cellulose, non-oily fats, and waxy lipids.
How is Hydrocarbon Extraction Different from Solvent-Less Extraction?
People say "solvent-less," but the process is not genuinely solvent-free. The highest quality "Solvent-less" extraction utilizes water, instead of hydrocarbons, to initially make bubble hash, and that extract is pressed and heated to produce oil. The water is essentially the solvent, which is very safe. But when you wash the water from the cannabis material, you also wash a bit of the flavor and fragrance.
Solvent-less extraction is a detailed, artisanal process that produces quality products, no doubt. But solvent-less extracts are extremely expensive–nearly twice the cost of hydrocarbon extracts. For a gram of solvent-less extract, consumers will pay $100 to $175.
The juice just isn’t worth the squeeze.
To be clear, many people will disagree with us and tout solvent-less extraction as the highest-grade process around. But when you compare the same product back-to-back, one produced through solvent-less and the other through hydrocarbon extraction, you can absolutely tell the difference in the aroma's potency.
How is Hydrocarbon Extraction Different From CO2 Extraction?
Hydrocarbon extraction is starkly different from CO2 extraction. In the past decade, CO2 has become immensely popular, but I believe it’s is a harsh method that uses very high pressure. I’ve heard of some companies using up to 10,000 PSI.
At such high pressure, you have a lot of added heat, which can degrade the compounds' integrity. Additionally, after CO2 extraction, some technicians conduct post-processing steps to remove the water content, excessive fats, and lipids to make the extract smokable. These extra steps can increase costs and the risk of cross-contamination.
The last few years have shown a shifting trend in the extract market that has caused issues for people who invested significant time and financial resources into systems that are becoming obsolete. We have seen companies in the California market shift to hydrocarbon and solvent-less extraction and away from CO2. Extractors still use CO2, but many have to follow up with distillation afterward depending on the process they’re using.
In cases where distillation is required, companies risk over-purifying and losing the broader spectrum of cannabinoids and terpenes in the process.
Is It Safe to Ingest Cannabis With Hydrocarbon Solvents?
Butane and propane are natural organic substances. They existed on this planet before we figured out how to isolate and push them into a tank. They are very similar to cannabis’s organic terpenes and cannabinoids, which are also types of hydrocarbons.
That doesn't mean you should ingest butane or propane in excess, but our products contain between 0 and 100 parts per million (ppm).
To provide more context, California's safe, legal limit on propane and butane is 5,000 parts per million. Some of the most dangerous and closely regulated pesticides like Fipronil have a tolerance of zero ppm. However, due to a testing lab’s detection limit, the actual limit becomes less than .0007 parts per million.
In short, California considers residual solvent hydrocarbons to be over 7 million times safer than the most dangerous pesticides. Additionally, if you have ever taken a breath while lighting a propane grill and noticed the smell of gas, you have inhaled thousands of times more hydrocarbons than you could ever get from the products we make.
How Does Your Hydrocarbon Extraction Process Differ From the Industry Standard?
We use the industry-standard process. However, we take extra care to purge the residual solvents slowly and gently avoid stripping the cannabinoids and terpenes away with them. We utilize a multi-day method to preserve cannabis's incredibly pungent aroma and therapeutic compounds while ensuring we leave no more than 100 ppm of residual solvents behind.
When companies rush the process, two outcomes can occur: Either they preserve the plant's flavor, aroma, and profile, leaving thousands of ppm of solvent behind, or they strip the plant of its naturally odorous compounds to ensure their products contain zero residual solvents.
Both outcomes leave you with safe, legally compliant products. But they force you to sacrifice quality.
What are the Potential Dangers of Hydrocarbon Extraction?
Residual solvents are a potential danger in any solvent-based extraction. That’s why we have safe manufacturing standards, legal safety limits, and stringent lab testing requirements in place. If a product fails a laboratory test for residual solvents, it will not make it to shelves or into a consumer's hands due to regulations.
To be sure, consumers can check products’ test results by looking up their Certificate of Analysis (COA).
Aside from residual solvents, people are mainly concerned with hydrocarbon fire risks. Due to propane and butane volatility, hydrocarbon extraction can present a serious fire hazard if managed improperly.
But most of the headline-making horror stories come from DIY-ers working out of their garages. In reality, modern hash labs that use proper equipment and protocols rarely have an issue.
The Bottom Line
Hydrocarbon extraction holds the potential to create high-quality cannabis products that Florida patients can afford. At ACS, we are thrilled that Florida's Office of Medical Marijuana Use expanded its definition of safe and legal extraction methods to include hydrocarbon extraction, and we look forward to testing all products to ensure they are 100% safe.