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VaporizersFrom Wikipedia, the free encyclopedia: The shortcomings of '''smoked''' cannabis have been widely viewed as a major obstacle for approval of [[Medical cannabis|medical marijuana]]; in response to the concerns several scientific studies have tried to establish whether vaporizers could offer a clinically reliable and safe method of cannabis use. Though vaporizers show great variations in performance, such studies have always found vaporization superior to smoking, and high-end vaporizers used with High Grade Hybrid Cannabis strains containing elevated levels of THC (the medicinal and psychoactive ingredient in cannabis) have been found to entirely eliminate inhalation of undesired compounds in a manner consistent enough for clinical trials. ==Types of vaporizers== Vaporizers are available in many varieties. Simple vaporizers use a lighter as heat source. Simple vaporizers are inexpensive and have expanded awareness of safer smoking alternatives. However they tend to either be ineffective or may result in accidentally burning the Marijuana. Precise vaporizers use an electric heating element often featuring a temperature control. Some vaporizers even have a dynamic temperature control as seen with systems that use thermocoupled hot air guns. High-end models may cost several hundred dollars. Broadly, vaporizers can be classified by how they heat the substance: With '''conduction''' heating, the substance is placed on a metal plate that is then heated to release the active constituents. The direct contact between hot metal and the herbs can cause them to burn. With '''convection''' heating, the substance itself never touches a heating element. Instead, hot air passes through it heating it rapidly and allowing the release of the active constituents. This method of heating releases far more active constituents than conduction heating, especially if the extraction chamber utilizes [[Venturi effect]] design.{{Fact|date=February 2007}} Many vaporizers use a tube (called a "whip") that is held to the heat source, and through which the user inhales the vapors. Some vaporizers have a bag or balloon attachment: vapor is blown into the bag, and the user detaches the bag and inhales the contents. Others are more direct extraction and delivery, such as the modular Vaporization "Tools" or "System" approach put forth by VripTech Int. with their VripMaster line which uses a direct venturi or sequential venturi extraction and delivery for maximum potency with delivery via a water pipe or, specialized "Vaporization Water Tool" which is basically a vapor specific water pipe that also holds ice for cooling and condensing the vapor, whilst minimizing oxidation, prior to delivery. Perhaps the most important classifications for vaporizers include the type of materials used in the heating element, the extraction chambers, and delivery means. Most common "wood box and whip" type vaporizers use a ceramic soldering iron element with a glass extraction chamber and a plastic hose for delivery. This is a low cost and effective approach; however, there are concerns about off-gassing of mercury gas from the solder that is present in wiring of the box and many enthusiasts cringe at the idea of inhaling aromatic vapors through a petroleum based hose for delivery. Some companies, such as VaporBrothers, are now using a higher-grade plastic hose while the makers of the higher end Vapezilla have opted for a silicone hose. The high end Volcano vaporizer uses an aluminum element that works quite well and a metallic extraction chamber with a food grade plastic bag for storage and delivery. Although the FDA considers aluminum heating elements that have not been anodized with a pigment to be compliant, there are concerns about using aluminum in any thermally sensitive application for long durations. The use of metal, a highly conductive material, in the extraction chamber means that to get consistent subsequent vapor extractions one must incrementally dial down the heat to compensate for the heat that is collected in the metal; the upside is that it is very durable. High end thermocoupled heat guns used for vaporization, such as those made by the German company Steinel and sold with the VripTech systems use a medical grade nichrome element encapsulated in ceramic and enclosed in stainless steel. ==Health and Medical Use== ==Scientific studies== In 2007, a study by [[University of California, San Francisco]] published in the Official Journal of the American Academy of Neurology{{cite news|url=http://www.sciencedaily.com/releases/2007/05/070515151145.htm|title=Marijuana Vaporizer Provides Same Level Of THC, Fewer Toxins, Study Shows|publisher=Official Journal of the American Academy of Neurology (summarized by [[Science Daily]])|date=05-16-2007|accessdate=2007-06-06}} examined the effectiveness of a vaporizer that heats cannabis to a temperature between 180 and 200 degrees and found: {{Cquote|Using CO as an indicator, there was virtually no exposure to harmful combustion products using the vaporizing device. Since it replicates smoking's efficiency at producing the desired THC effect using smaller amounts of the active ingredient as opposed to pill forms, this device has great potential for improving the therapeutic utility of THC}} In 2006, a study performed by researchers at [[Leiden University]], tested a [[Volcano Vaporizer]] with preparations of pure THC and found that: {{Cquote|Our results show that a safe and effective [[cannabinoid]] delivery system seems to be available to patients. The final pulmonal uptake of THC is comparable to the smoking of cannabis, while avoiding the respiratory disadvantages of smoking.}} When using plant material (crude flower tops), besides THC, several other cannabinoids as well as a range of other plant components including [[Terpene|terpenoids]] were detected in the plant material. However, using pure THC in the Volcano, no degradation products ([[delta-8-THC]] (D8-THC), [[cannabinol]] (CBN), or unknown compounds) were detected by [[High performance liquid chromatography|HPLC]] analysis. Also, a substantially larger fraction of the THC was delivered to the vapor by using pure THC. Analysis of the vapor from the Volcano found that using multiple passes it delivered 36% - 61% of the THC in the sample - a more recent study using pure cannabinoid preparations achieved a maximum of 54%. In a 2001 study testing a device called the M1 Volatizer® , the researchers found that "it is possible to vaporize medically active THC by heating marijuana to a temperature short of the point of combustion, thereby eliminating or substantially reducing harmful smoke toxins that are normally present in marijuana smoke." The M1 Volatizer, produced THC at a temperature of 365 degrees Fahrenheit (185 degrees Celsius), while completely eliminating three measured combustion products, [[benzene]], [[toluene]] and [[naphthalene]]. [[Carbon monoxide]] and smoke [[tar]]s were also reduced, but not quantified. These positive results are in contrast to [[MAPS]]/[[NORML]]'s previous studies into vaporizers which found less encouraging results, leading one to the conclusion that the effectiveness of vaporization varies greatly from vaporizer to vaporizer. See [[Vaporizer#Factors affecting vaporizer output|Factors affecting vaporizer output]] for possible causes of variation. A 1996 MAPS study tested two simple vaporizer models against water pipes and filtered and unfiltered cannabis cigarettes ([[joint (cannabis)|joint]]s). The smoke produced by each was analyzed for solid particulates (tars) and 3 major cannabinoids. The various smoking methods were then rated based on their cannabinoid-to-tar ratio. The two tested vaporizers performed up to 25% better than unfiltered cannabis cigarettes (second best) in terms of tar delivery. However, both vaporizers produced more than ten times more tars than cannabinoids, which may partly be attributable to the low potency (2.3%) of the [[NIDA]]-supplied cannabis used in the study. Surprisingly, the same study found that water pipes ([[bongs]]) and filtered cigarettes performed 30% ''worse'' than regular, unfiltered joints. The reason was that waterpipes and filters filter out psychoactive THC with the tars, thereby requiring users to smoke more to reach their desired effect. The study did not, however, rule out the possibility that waterpipes could have other benefits, such as filtering out harmful gases such as carbon monoxide. These studies have not measured the presence of toxic gases, such as [[ammonia]], [[hydrogen cyanide]] and carbon monoxide, though previous studies have indicated unquantified decreases in carbon monoxide with vaporization. Although vaporizers produce cleaner vapors than smoking, they do not completely eliminate respiratory irritation. A puff of strong vaporized cannabis will occasionally cause coughing. This however, could be due to THC itself, which is known to have a strong expectorant effect. ===Factors affecting vaporizer extraction and delivery capabilities and the breadth of spectrum of actives deliverable=== The wide range of results from tests of different vaporizers suggest that the choice of vaporizer is a major factor in determining extraction and delivery efficiency as well as the amount of harmful byproducts produced, or not produced, as in the case of a superior system. In Cannabis, and many other medicinal plants, the components responsible for the aromatic nature of the plant will often vaporize at a low-end temperature in the range of extraction temperature values for all the bioactive components. In Cannabis, the temperature range across which the actives will vaporize is at least 132 degrees F starting at around 260F where only aromatic compounds of minimal bioactivity will release and going all the way up to 392F with the higher end of this range representing where the cannabinoids of higher bioactivity appear to be released. It is believed that both the total amount of actives delivered as well as the breadth of spectrum delivered per inhalation is critical in determining the value of the delivered dose and, in turn, systems that deliver the highest amount of actives and broadest spectrum of actives per inhalation are believed to be the most effective for medicinal applications: i.e. venturi enhanced extraction / convection based systems. Proposed factors affecting output include , : *temperature; Not all those have been scientifically tested. Research using the vaporizer found the delivery efficiency highest at around 226 degrees Celsius, falling to about half efficiency at 150 to 180 degrees depending on material . The longer vapor is stored, the more of the THC is lost as it condenses on the surface of the vaporizer or the balloon. This loss may be negligible over a few minutes but may exceed 50% after 90 minutes . Interestingly, the Leiden Univsersity study found that as much as 30%–40% of inhaled THC was not absorbed by the lungs and simply exhaled. However, they did not find large individual differences in the amounts exhaled. ==Byproducts== '''Browns or Duff''' are the used up herb after vaporization. Instead of being black like ashes they are brown. Though they are in low concentrations, cannaboids may be recovered from an accumulation of Browns using an extraction (such as [[ethanol]]) or may be re-vaped. '''Scrapings''' are the buildup of resin in a vaporizer. This buildup may be ''scraped'' and vaped for a potent effect, similar to kief. ==Vaporizing For Enhanced Lung Capacity Technique==
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