Hash oil
Hash oil or cannabis oil is an oleoresin obtained by the extraction of cannabis or hashish. It is a cannabis concentrate containing many of its resins and terpenes – in particular, tetrahydrocannabinol, cannabidiol, and other cannabinoids. Hash oil is usually consumed by smoking, vaporizing or eating. Preparations of hash oil may be solid or semi-liquid colloids depending on both production method and temperature and are usually identified by their appearance or characteristics. Color most commonly ranges from transparent golden or light brown, to tan or black. There are various extraction methods, most involving a somewhat nonpolar solvent, such as butane or ethanol.
Hash oil is an extracted cannabis product that may use any part of the plant, with minimal or no residual solvent. It is generally thought to be indistinct from traditional hashish, at-least according to the 1961 UN Single Convention on Narcotic Drugs that defines these products as "the separated resin, whether crude or purified, obtained from the cannabis plant".
Hash oil may be sold in cartridges to be used with pen vaporizers or infused into food products. Cannabis retailers in California have reported about 40% of their sales are from smokeable cannabis oils.
Composition
The tetrahydrocannabinol varies depending on preparation techniques and the variety of plant used. Dealers sometimes cut hash oils with other oils. The form of the extract varies depending on the extraction process used; it may be liquid, a clear amber solid, a sticky semisolid substance, or a brittle honeycombed solid.Hash oil seized in the 1970s had a THC content ranging from 10% to 30%. The highest THC concentrations measured were 52.9% in hashish and 47.0% in hash oil. Hash oils in use in the 2010s had THC concentrations as high as 90% and other products achieving higher concentrations.
Following an outbreak of vaping-related pulmonary illnesses and deaths in 2019, NBC News conducted tests on different black market THC vape cartridges and found cartridges containing up to 30% Vitamin E acetate, and trace amounts of fungicides and pesticides that may be harmful.
The following compounds were found in naphtha extracts of Bedrocan Dutch medical cannabis:
- Cannabinoids: THC and THCA.
- Monoterpenes : β-pinene, myrcene, β-phellandrene, cis-ocimene, terpinolene, and terpineol.
- Sesquiterpenes : β-caryophyllene, humulene, δ-guaiene, γ-cadinene, eudesma-3,7-diene, and elemene.
History
Discovery and development
The hash oils made in the 19th century were made from hand collected hashish called charas and kief. The term hash oil was hashish that had been dissolved or infused into a vegetable oil for use in preparing foods for oral administration. Efforts to isolate the active ingredient in cannabis were well documented in the 19th century, and cannabis extracts and tinctures of cannabis were included in the British Pharmacopoeia and the United States Pharmacopoeia. These solvent extracts were termed cannabin, cannabindon, cannabinine, crude cannabinol and cannabinol.Modern usage
So-called "butane honey oil" was available briefly in the 1970s. This product was made in Kabul, Afghanistan, and smuggled into the United States by The Brotherhood of Eternal Love. Production is thought to have ceased when the manufacturing facility was destroyed in an explosion.Traditional ice water-separated hashish production utilizes water and filter bags to separate plant material from resin, though this method still leaves much residual plant matter and is therefore poorly suited for full vaporization. Gold described the use of grain alcohol and activated charcoal in honey oil production by 1989, and Michael Starks further detailed procedures and various solvents by 1990.
Large cannabis vaporizers gained popularity in the twentieth century for their ability to vaporize the cannabinoids in cannabis and extracts without burning plant material, using temperature controlled vaporization. Colorado and Washington began licensing hash oil extraction operations in 2014. Small portable vape pens saw a dramatic increase in popularity in 2017.
Use
Hash oil is consumed usually by ingestion, smoking or vaporization.Dabbing
Smoking or vaporizing hash oil is known colloquially as "dabbing", from the English verb to daub, "to smear with something adhesive". Devices used for this process include water pipes, vaporizers, and vape pens. Oil rigs include a glass water pipe and a quartz bucket which is often covered with a glass bubble or directional cap to direct the airflow and disperse the oil amongst the hot areas of the quartz "nail". The pipe is often heated with a butane blowtorch rather than a cigarette lighter.The oil can also be sold in prefilled atomizer cartridges. The cartridge is used by connecting it to a battery and inhaling the vaporized oil from the cartridge's mouthpiece.
Production
Solvent extracts
Hash oil is produced by solvent extraction of marijuana or hashish.Fresh, undried plant material is less suited for hash oil production, because much THC and CBD will be present in their carboxylic acid forms, which may not be highly soluble in some solvents.
A wide variety of solvents can be used for extraction, such as chloroform, dichloromethane, petroleum ether, naphtha, benzene, butane, methanol, ethanol, isopropanol, and olive oil.
The majority of ready to consume extract products are produced via "Closed Loop Systems". These systems typically entail: a vessel that holds the solvent, material columns to hold the plant material, a flow meter to measure the volume of solvent entering the plant material, a recovery vessel to convert the liquid solvent into a vapor and separate it from the THC, CBD, or other cannabinoids/byproducts, and some form of a heat exchanger to then convert the hydrocarbon vapors back into a liquid form prior to returning to the original vessel. Such a process can be carried out using a Soxhlet extractor.
Ten grams of marijuana yields one to two grams of hash oil. The oil may retain considerable residual solvent: oil extracted with longer-chain volatile hydrocarbons is less viscous than oil extracted with short-chain hydrocarbons.
Colored impurities from the oil can be removed with activated charcoal. When decolorizing fatty oils, oil retention can be up to 50 wt % on bleaching earths and nearly 100 wt % on activated charcoal. The many different textures/types of hydrocarbon extracts include:
- shatter
- pull and snap
- diamonds/live resin
- crumble
- budder/wax
Solventless extracts: Hash rosin
This hash is then pressed at the appropriate temperature and pressure to squeeze the oils out of the hash, and is collected with metal tools and parchment paper. Just like hydrocarbon extraction, the quality of the final product depends greatly on the quality of the starting material. This is emphasized even more so with hash rosin due to its lower yield percentages compared to solvent-derived concentrates. Hash rosin producers often touch on how growing cannabis for hash production is different than growing for flower production, as some strains will be deceptive with their looks regarding yields.
Legality
In Canada, hash oil – defined as a chemically concentrated extract having up to 90% THC potency – was approved for commerce in October 2018.In the United States, regulations specifically for hash oil have not been issued as of 2019, but hemp seed oil – along with hulled hemp seeds and hemp seed protein – were approved as generally recognized as safe in December 2018, indicating that "these products can be legally marketed in human foods for these uses without food additive approval, provided they comply with all other requirements and do not make disease treatment claims".
In Germany, the KCanG from April 1, 2024 allows the possession of a certain amount of Cannabis products for adults. However, extraction of cannabinoids from the plants, and thus hash oil, is still illegal in general. The term extraction is not defined in the law but refers in most definitions to the use of an extractive such as butane or ethanol. As this is not used in the production of rosin it is uncertain whether rosin is a legal cannabis resin according to KCanG due to the mechanical process of production or an illegal one, since of the extractive purpose.