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E-Cigarettes: A Review of New Trends in Cannabis Use.

Giroud C, de Cesare M, Berthet A, Varlet V, Concha-Lozano N, Favrat B - Int J Environ Res Public Health (2015)

Bottom Line: First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette.Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear.The most significant health concerns involve the vaping of cannabinoids by children and teenagers.

View Article: PubMed Central - PubMed

Affiliation: Forensic Toxicology and Chemistry Unit, University Center of Legal Medicine (CURML), CH-1000 Lausanne 25, Switzerland. christian.giroud@chuv.ch.

ABSTRACT
The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

No MeSH data available.


Related in: MedlinePlus

Manufacture of ground cannabis head buds, butane honey oil extract and cannabis e-liquid. 1–3. Processing cannabis heads and smoking them in a dry herb vaporizer; 4–9. Manufacture of cannabis oil concentrate and vaping with a wax vaporizer; 10–11. Making a cannabis e-liquid and vaping in a regular e-cigarette or e-mod.
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getmorefigures.php?uid=PMC4555324&req=5

ijerph-12-09988-f003: Manufacture of ground cannabis head buds, butane honey oil extract and cannabis e-liquid. 1–3. Processing cannabis heads and smoking them in a dry herb vaporizer; 4–9. Manufacture of cannabis oil concentrate and vaping with a wax vaporizer; 10–11. Making a cannabis e-liquid and vaping in a regular e-cigarette or e-mod.

Mentions: The preparation of marijuana vape e-liquids requires several steps (see Figure 3): cannabinoids from dried and finely pulverized cannabis flower buds must be heat-activated, extracted, and purified. After harvesting and drying the raw mature plants, the flower tops are ground to fine particles. The milled fragments are then heated (range, 230 °F–310 °F or 110 °C –160 °C) to convert the inactive natural acid plant precursor, tetrahydrocannabinolic acid A (THC-A), into its neutral and psychoactive THC counterpart [15,16]. At the same time, the other acid cannabinoids are also converted to their neutral counterparts by heat-decarboxylation. Overheating must be avoided because it may result in a degradation of the THC and the formation of substantial amounts of cannabinol. Lower temperatures require longer decarboxylation times (>1 h), but they preserve most of the cannabinoids and the aromatic and volatile terpenoids, and prevent losses of THC by evaporation. However, this heat-decarboxylation step generates CO2 and an increase in pressure, creating a risk that the container might burst and rupture. To mitigate their degradation by oxidation and evaporation, the plant fragments must be thermally processed in a large, closed, robust container filled with inert gas (e.g., nitrogen, argon). This decarboxylation stage (see Figure 3, step 3) can take place before or after the extraction (step 3) and purification phase (step 5) of the plant’s cannabinoids. Besides using organic solvents (e.g., ethanol, isopropanol), some of the most popular extraction methods involve using dry ice (non-flammable solid pellets of frozen carbon dioxide, CO2), highly inflammable liquid gases such as butane, or low-viscosity supercritical (SC) fluids such as SC-CO2. These methods have several advantages: extraction is rapid and takes place at very low or moderate temperatures; after elution, filtration through a coarse cellulose filter (e.g., coffee filter or Whatman 595 filter paper), depressurization, and heating, CO2 or butane is vented to leave a crude cannabinoid-enriched fraction. Any remaining traces of extracting fluid are very easily eliminated by evaporation at moderate temperatures (e.g., 140 °F or 60 °C in a water bath). This soft extraction process preserves the chemical integrity of the cannabinoids. The main drawbacks are the risks of gas inhalation or explosion. The resulting waxy concentrates are named CO2 and BHO (butane honey oil). These relatively crude extracts can be further purified by ethanol solubilization, followed by slow, deep-freeze precipitation (for at least 2 days) and the out-filtration of unwanted waxes and triglycerides via a glass wool filter in a separating funnel. This process, known as winterization, is the classic bio-industry method to remove traces of waxes and high-melting glycerides from fats. Skipping this step may expose the consumer to a risk of lipid pneumopathy. Exogenous lipoid pneumonia [17] due to vaping of glycerol-based e-liquids may also occur [18]. Lastly, the ethanol phase and solvent residues are evaporated at 40 °C–60 °C, or in a tepid bain-marie, under a fume hood and dried in an evacuated bell jar or a vacuum chamber. The purified yellow, wax-like residue is kept in the dark in an airtight container before consumption. Even tiny amounts of these concentrates, which can be put in the small-volume containers of e-cigs and mods, contain sufficient amounts of THC to provide the desired, typical psychoactive effects of cannabis [19]. This purified concentrate can be also mixed and diluted with pure propylene glycol (PG) or with mixtures of polyethylene glycols and PG, as advocated by EJMIX (Liquidizer, Bloomsdays, USA) providers and users [20].


E-Cigarettes: A Review of New Trends in Cannabis Use.

Giroud C, de Cesare M, Berthet A, Varlet V, Concha-Lozano N, Favrat B - Int J Environ Res Public Health (2015)

Manufacture of ground cannabis head buds, butane honey oil extract and cannabis e-liquid. 1–3. Processing cannabis heads and smoking them in a dry herb vaporizer; 4–9. Manufacture of cannabis oil concentrate and vaping with a wax vaporizer; 10–11. Making a cannabis e-liquid and vaping in a regular e-cigarette or e-mod.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4555324&req=5

ijerph-12-09988-f003: Manufacture of ground cannabis head buds, butane honey oil extract and cannabis e-liquid. 1–3. Processing cannabis heads and smoking them in a dry herb vaporizer; 4–9. Manufacture of cannabis oil concentrate and vaping with a wax vaporizer; 10–11. Making a cannabis e-liquid and vaping in a regular e-cigarette or e-mod.
Mentions: The preparation of marijuana vape e-liquids requires several steps (see Figure 3): cannabinoids from dried and finely pulverized cannabis flower buds must be heat-activated, extracted, and purified. After harvesting and drying the raw mature plants, the flower tops are ground to fine particles. The milled fragments are then heated (range, 230 °F–310 °F or 110 °C –160 °C) to convert the inactive natural acid plant precursor, tetrahydrocannabinolic acid A (THC-A), into its neutral and psychoactive THC counterpart [15,16]. At the same time, the other acid cannabinoids are also converted to their neutral counterparts by heat-decarboxylation. Overheating must be avoided because it may result in a degradation of the THC and the formation of substantial amounts of cannabinol. Lower temperatures require longer decarboxylation times (>1 h), but they preserve most of the cannabinoids and the aromatic and volatile terpenoids, and prevent losses of THC by evaporation. However, this heat-decarboxylation step generates CO2 and an increase in pressure, creating a risk that the container might burst and rupture. To mitigate their degradation by oxidation and evaporation, the plant fragments must be thermally processed in a large, closed, robust container filled with inert gas (e.g., nitrogen, argon). This decarboxylation stage (see Figure 3, step 3) can take place before or after the extraction (step 3) and purification phase (step 5) of the plant’s cannabinoids. Besides using organic solvents (e.g., ethanol, isopropanol), some of the most popular extraction methods involve using dry ice (non-flammable solid pellets of frozen carbon dioxide, CO2), highly inflammable liquid gases such as butane, or low-viscosity supercritical (SC) fluids such as SC-CO2. These methods have several advantages: extraction is rapid and takes place at very low or moderate temperatures; after elution, filtration through a coarse cellulose filter (e.g., coffee filter or Whatman 595 filter paper), depressurization, and heating, CO2 or butane is vented to leave a crude cannabinoid-enriched fraction. Any remaining traces of extracting fluid are very easily eliminated by evaporation at moderate temperatures (e.g., 140 °F or 60 °C in a water bath). This soft extraction process preserves the chemical integrity of the cannabinoids. The main drawbacks are the risks of gas inhalation or explosion. The resulting waxy concentrates are named CO2 and BHO (butane honey oil). These relatively crude extracts can be further purified by ethanol solubilization, followed by slow, deep-freeze precipitation (for at least 2 days) and the out-filtration of unwanted waxes and triglycerides via a glass wool filter in a separating funnel. This process, known as winterization, is the classic bio-industry method to remove traces of waxes and high-melting glycerides from fats. Skipping this step may expose the consumer to a risk of lipid pneumopathy. Exogenous lipoid pneumonia [17] due to vaping of glycerol-based e-liquids may also occur [18]. Lastly, the ethanol phase and solvent residues are evaporated at 40 °C–60 °C, or in a tepid bain-marie, under a fume hood and dried in an evacuated bell jar or a vacuum chamber. The purified yellow, wax-like residue is kept in the dark in an airtight container before consumption. Even tiny amounts of these concentrates, which can be put in the small-volume containers of e-cigs and mods, contain sufficient amounts of THC to provide the desired, typical psychoactive effects of cannabis [19]. This purified concentrate can be also mixed and diluted with pure propylene glycol (PG) or with mixtures of polyethylene glycols and PG, as advocated by EJMIX (Liquidizer, Bloomsdays, USA) providers and users [20].

Bottom Line: First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette.Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear.The most significant health concerns involve the vaping of cannabinoids by children and teenagers.

View Article: PubMed Central - PubMed

Affiliation: Forensic Toxicology and Chemistry Unit, University Center of Legal Medicine (CURML), CH-1000 Lausanne 25, Switzerland. christian.giroud@chuv.ch.

ABSTRACT
The emergence of electronic cigarettes (e-cigs) has given cannabis smokers a new method of inhaling cannabinoids. E-cigs differ from traditional marijuana cigarettes in several respects. First, it is assumed that vaporizing cannabinoids at lower temperatures is safer because it produces smaller amounts of toxic substances than the hot combustion of a marijuana cigarette. Recreational cannabis users can discretely "vape" deodorized cannabis extracts with minimal annoyance to the people around them and less chance of detection. There are nevertheless several drawbacks worth mentioning: although manufacturing commercial (or homemade) cannabinoid-enriched electronic liquids (e-liquids) requires lengthy, complex processing, some are readily on the Internet despite their lack of quality control, expiry date, and conditions of preservation and, above all, any toxicological and clinical assessment. Besides these safety problems, the regulatory situation surrounding e-liquids is often unclear. More simply ground cannabis flowering heads or concentrated, oily THC extracts (such as butane honey oil or BHO) can be vaped in specially designed, pen-sized marijuana vaporizers. Analysis of a commercial e-liquid rich in cannabidiol showed that it contained a smaller dose of active ingredient than advertised; testing our laboratory-made, purified BHO, however, confirmed that it could be vaped in an e-cig to deliver a psychoactive dose of THC. The health consequences specific to vaping these cannabis preparations remain largely unknown and speculative due to the absence of comprehensive, robust scientific studies. The most significant health concerns involve the vaping of cannabinoids by children and teenagers. E-cigs could provide an alternative gateway to cannabis use for young people. Furthermore, vaping cannabinoids could lead to environmental and passive contamination.

No MeSH data available.


Related in: MedlinePlus