WHAT IS BUTANE?
Butane is an organic hydrocarbon with the formula C4H10. It has a boiling point of around 0° C (31° F), making it a gas at normal room temperature and pressure. There are two isomers of butane, each with slightly different chemical properties; n-butane has 4 carbon atoms connected in a chain surrounded by 10 hydrogen atoms, and iso-butane has 4 carbon atoms arranged in a “T,” surrounded by 10 hydrogen atoms. Unless otherwise specified, ‘butane’ refers to the n-isomer.
BUTANE AS A SOLVENT
Most BHO extraction operators prefer n-butane due to its lower operating pressure and low vapor pressure.
Butane is relatively non-polar; the molecule has a symmetrical arrangement and none of the bonds are significantly polar, meaning the molecule has almost no charge. As a rule, like dissolves like. In other words, polar solutes will to dissolve in polar solvents, and vice-versa.
THC and CBD, along with a large variety of other terpenoids, are relatively non-polar and will readily dissolve in butane, along with lipids and waxes. Chlorophyll, a green pigment found in most plants, can contribute to foul taste and discolouration of cannabis derived extracts. Fortunately, chlorophyll is relatively polar and does not readily dissolve in butane.
WHAT IS BUTANE HASH OIL (BHO)?
Butane hash oil — or BHO, as it is more commonly known — is a highly concentrated form of cannabis oil. Once collected, the oil is often smoked directly or vaped.
As the name suggests, butane hash oil is created using the butane extraction method. There are numerous different types of BHO on the market including budder, dabs, wax, and shatter.
Consumers find these extracts appealing due to their relatively high THC content. At the high end, these products may have THC concentrations of nearly 90 percent — four times the typical percentage found in an average bud. Intuitively, this exceptionally high THC content will lead to a faster and stronger high when compared with smoking traditional leaf cannabis. Popular shatters and waxes can be created using either butane or supercritical extraction, and a given producer may prefer one method to another for various reasons, including operational limitations.
FEATURES
Often featuring between 60 and 90 percent THC, BHO is one of the strongest cannabis products on the market.
Though BHO often gets a bad rap, this form of extraction creates a delightful end product. BHO tends to be flavorful and features stronger terpene expression than CO2 extraction. Terpenes are flavor and aroma molecules found in plant resins. This means that consumers will get an excellent feel of an individual strain.
Unfortunately, BHO does have a major downside. BHO is more likely to contain residual solvents, which can be irritating to the lungs and exposes your body to excess pollution. BHO that is professionally extracted and has passed laboratory tests contains a low risk of residual solvents. Though, homemade extracts are often not pure.
PROS
Lower cost of entry for extraction systems
Hydrocarbons’ low boiling point preserves more of the cannabinoids and terpenes for a full-spectrum extract
Wide variety of products available, with differing tastes and effects
Faster runs than CO2 extractions
Can produce a wide variety of extract solutions ranging from distillates to high-terpene full-spectrum extracts (HTFSE).
Often considered a stronger product
CONS
In an unsafe environment or when handled improperly, the highly flammable solvent can increase the risk of fire and explosion
When used improperly, it can increase the risk of residual solvents ending up in the final product.
More difficulty gaining approval from jurisdiction
May come with higher facility costs
Not as environmentally friendly as CO2 since butane and propane are petroleum products
WHO IS BUTANE EXTRACTION (BHO EXTRACTION)?
Butane extraction, sometimes referred to as butane hash oil extraction (BHO extraction), is a popular method of extracting the valuable compounds from the cannabis plant to essentially create a cannabis concentrate.
The end result is known as butane hash oil (BHO), which is what is used to make up man other forms of consumable cannabis concentrates, like shatter, wax, honey oil, nug run, and so on.
Butane extraction is a form of hydrocarbon extraction, which is the process of using a hydrocarbon like butane or propane as the solvent to extract cannabis concentrates.
To extract cannabis compounds from the plant, a solvent is typically used. In addition to butane extraction methods, other types of cannabis extraction include CO2 extraction, alcohol extraction, and dry sieving extraction. There is also what is known as the ‘rosin’ technique that is becoming popular.
For the butane extraction method, the user first tightly packs a glass cylinder with marijuana. At one end of the glass tube, a screen ensures plant material does not fall out. This screened end is held over another glass receptacle. Next, a butane torch is held or affixed to the opposite end of the glass tube, and butane is blown into the tube. The heated cannabis plant material will eventually release its oils and resins, which are collected in the additional container.
Before consumption, the oils and resins must be cleared (purged) of the butane solvent. To do so, the solution is simply heated in hot water (almost boiling). Butane bubbles form in the oil and eventually pop, releasing gas into the atmosphere. The final result is considered by many to be a clean, solvent-free product safe for consumption. However, some people will argue that any residual solvent left in the concentrate is unacceptable.
It is typically argued that BHO products are harsher on the lungs, even when a vaporizer is used.
NOTES
The National Fire Protection Association has assigned a flammability rating of 4 (on a scale of 0 to 4), classifying n-butane as extremely hazardous. For these reasons, most states that allow for BHO extraction systems require a properly ventilated Class 1/Division 1 explosion-proof room. Both the room and BHO extraction system must be inspected by a certified industrial hygienist or engineer to be sure they conform to regional and municipal codes and nationally recognized accreditations. Workers must be adequately trained and understand the hazards associated with working with closed loop BHO extraction systems.