Why Solventless Extraction Is Better for Your Business & the Planet
Solvent-derived cannabis extracts like wax and shatter are in high demand, but solventless extractions can offer an even better experience to consumers without the environmental and manufacturing downsides. If you’re a cannabis extraction tech, product maker, or dispensary owner, consider just a few of the reasons why going solventless may be a sound business decision.
What Is Solventless Extraction?
When we’re talking about cannabis, extraction refers to the process of removing and collecting active compounds from the plant, usually with the help of a solvent like butane, ethanol, propane, or carbon dioxide (CO2). For example, CBD oil is a type of extract because the compound cannabidiol is separated from the plant and repurposed as a new product. Common marijuana extracts include shatter, wax, budder, crumble, and tinctures.
“Solventless extraction” refers to any extraction that doesn’t require the use of a solvent. A typical solventless extraction involves separating the trichomes (the parts of the plant that house most of its sticky resin) from the plant by hand or machine and then applying pressure and gently heating it to perform the extraction. Rosin is the best-known solventless extract, though other options are quickly gaining popularity.
It’s important to clarify what we mean by “extract,” as the term is often falsely conflated with “concentrate” (a category that includes hashish and kief). Traditionally, the solvent is what differentiates extracts from concentrates, but the jury is still very much out on definitive nomenclature for these terms.
- Extracts are made with hydrocarbon-based solvents or heated/pressurized CO2.
- Concentrates are made either mechanically, by hand, or with non-heated CO2.
Solventless extractions are commonly created by various applications of ice water, mechanical shearing of trichomes, applying heat and pressure to trichomes to push them through a filter, or other concentrates without the use of CO2, hydrocarbons, or alcohols. An example would be to convert bubble hash (a concentrate) into rosin (a solventless extract) via manual heating and pressure application.
Why Solvents Are Used in Cannabis Extractions
Solvents serve a meaningful purpose. They’re able to break down the cannabis plant into its cannabinoids, terpenes, and other compounds, producing a precise extraction with little waste. CO2 has become especially popular for this purpose because it evaporates and is non-combustible, so the resulting extract is especially pure.
In some cases, solvents are even required. If, for example, you’re trying to create a broad-spectrum CBD product (with 0% THC) or a CBD isolate product (with only CBD and no other cannabinoids), you traditionally need to employ complex chemical processes that give you greater control of your cannabinoid ratios. With a solventless extraction, you’re typically stuck with the full cannabinoid and terpene profile of your base concentrate.
The other benefit of using solvents is that they make large-scale operations feasible. If you’re trying to extract acres’ worth of cannabis into a line of dab-friendly consumables, it’s extremely inefficient to process and pressurize all of that plant matter unless you have some truly state-of-the-art equipment.
For smaller operations, however, and for anyone looking to cut costs and reduce their carbon footprint, there are benefits to allocating more time and resources to solventless extractions.
Why Solventless Extractions Are Gaining Popularity
For businesses, there are a few key benefits of going solventless:
- Solventless extractions are most likely better for the environment.
- Solventless extractions typically are more cost-effective for small businesses.
- Solventless extractions don’t involve using flammable solvents and are deemed safer.
- Solventless extractions have less complicated waste disposal requirements.
- Solventless extractions typically contain fewer impurities because of the stringent demands of high quality input material to begin with.
Let’s break them down one by one.
Solventless Extractions Are Better for the Environment
Chemical-based solvents carry an enormous carbon footprint. Solutions like butane, ethanol, and propane pollute local water supplies and release volatile organic compounds (VOCs) into the environment.
VOCs are becoming an increasingly prevalent concern in the growing cannabis market, as larger markets like Denver, Colorado have experienced increased ozone levels due in part to the abundance of cannabis-based VOCs in the environment. In addition, high concentrations of VOCs can contribute to respiratory irritation, liver damage, and certain cancers.
It’s important to note that cannabis itself is a VOC-producer, with or without solvents. Nevertheless, eco-conscious cannabis cultivators should take steps to keep their VOC output to a minimum, and this may include minimizing the use of solvents that exacerbate the problem.
Solventless Extractions Are More Cost-Effective for Small Businesses
For large-scale operations, solvents can make financial sense. For small businesses, though, they can be more of a financial burden than an asset. For example, a quality CO2 extraction machine (the gold standard of extraction tools) can easily cost over $200,000, and often go much higher than that. A high-quality hydrocarbon system or ethanol extraction centrifuge can run $30,000 to $60,000. And while much cheaper options are available, the budget extraction machines tend to be vastly inferior in terms of throughput, product quality, ease of use, and safety.
And that’s just the up-front cost. When you factor in the cost of the solvents, the mandated laboratory setup (required for licensure), and the experienced personnel (most of these extraction methods require an intermediate to advanced chemistry background), you’re looking at an annual cost that can easily creep into the millions—just for a moderate-sized operation.
Solventless extractions are much more cost-effective. The highest-quality industrial rosin presses can be purchased for under $10,000, and some can be acquired for as little as $3,000. There are no solvents required, and most of the tools you need—mesh screens, bubble bags, pollen presses, and assorted accessories—can be purchased inexpe. Anyone can be trained to use this type of machinery.
Solventless Extractions Are Safer
Most solvents are highly flammable. Responsible extraction techs know how to mitigate the risks using a well-controlled closed-loop extraction system, but the risks nevertheless exist. There are numerous stories and videos of explosions occurring at butane hash oil (BHO) production facilities, which usually occur when extractors cut corners, use inferior equipment, or overlook important safety measures.
For example, improper ventilation combined with leaking butane lines can create the perfect environmental conditions for combustion. Some amateur extractors will also try to use heat to speed up the extraction process, such as by using a stovetop burner. Adding this kind of oxygen source to butane is a lot like dropping a match over gasoline vapor. If you do use solvents, it’s absolutely critical to take every safety measure, inspect your equipment regularly, and avoid taking shortcuts.
Solventless Extractions Have Less Complicated Waste Disposal Requirements
The requirements for cannabis waste disposal are already complicated enough. You have to track and trace your waste from cradle to grave. You have to render your waste unusable and unrecognizable. You have to document the entire disposal process. You have to ensure that your waste is sent to an authorized facility and weighed a final time.
The process gets even more complicated when you add hazardous waste—such as butane, propane, or ethanol—into the mix. When you’re extracting, cultivating, packaging, or selling cannabis products, you must separate your hazardous chemical waste from your non-hazardous plant waste. And while the exact requirements vary from one jurisdiction to the next, you’re usually required to separate each class of hazardous waste into separate bins, each with its own label detailing the waste profile. These streams of waste must then be scheduled for hazardous waste pickup.
When dealing with any type of cannabis waste, it’s absolutely critical that you work with a reputable cannabis waste disposal provider. The requirements are just too complex to manage on your own, and the stakes are too high. But by minimizing your dependence on hazardous waste, you can reduce your own potential liability as you manage your waste streams on site prior to pickup.
Solventless Extractions Typically Contain Fewer Impurities
A skilled extraction tech can produce a high-quality wax, ISO hash, or BHO with few to no impurities. Nevertheless, it’s possible for excess butane to remain in the finished product, especially when you’re using standard-grade equipment.
Some BHO products have tested with butane concentrations as high as 50,000 parts per million, which is about 2-5% butane in a typical extract. Although the risk of butane toxicity is low, it’s still something that producers and consumers should be cautious about. The abuse of butane-based products has been linked to harmful central nervous system (CNS) reactions and cardiac effects.
With solventless extraction, you don’t have to worry about these types of impurities as long as you start with a quality marijuana product and follow best practices. With ice water extraction, you can even produce a 5- to 6-melt hash product that’s as pure or purer than anything you’d get from a high-end CO2 machine.
Is Solventless Extraction the Future of Concentrates?
It’s possible that solvents like butane and ethanol may ultimately be phased out altogether as superior extraction methods are developed. For example, savvy extraction techs have developed a solventless shatter that has the same glass-like consistency of traditional shatter—but without the butane. It’s produced via selective breeding combined with the optimal combination of heat, pressure, and exposure.
And as breeders develop strains of cannabis with precisely targeted cannabinoid and terpene ratios, it becomes easier to achieve desired THC and CBD concentrations without having to selectively extract the compounds within the plant. For example, a Kentucky firm has already developed a strain of hemp with 0.0% THC, which may make it possible to create broad-spectrum CBD products without the need for solvents.
There may always be a place for solvent-based extractions, but if you incorporate a few solventless alternatives into your own business or personal efforts, you may find yourself with a better product and an improved bottom line.