Vaporizer (inhalation device)

For the device used in surgery, see anaesthetic vaporiser.

For the device commonly called a vaporizer used in humidifying, see humidifier.

A conduction-style vaporizer. The material to be vaporized is placed on the electrically heated metal plate in the center. The vapors are contained in the glass bell and inhaled through the plastic tube in the foreground.

A vaporizer (or vapouriser) is a device used to release the active ingredients of plant material, commonly cannabis, or tobacco, or to release therapeutic compounds from herbs (phyto-inhalation; see also: aromatherapy). Vaporizing is an alternative to smoking. Rather than burning the herb (which produces numerous harmful by-products), a vaporizer heats the material (to ideally 180 degrees Celsius) so that the active compounds contained in the plant sublimate (go from a solid to a gas) producing vapor, not smoke. This vapor ideally contains reduced amounts of particulate matter (tar) and carcinogens such as carbon monoxide. Vapors may be filtered and cooled further using a water pipe or an inline water/ice attachment. Vapors are then inhaled or stored for subsequent inhalations in a "dome" or "balloon". With little to no smoke produced, cooler temperatures, and less material required to achieve the same effect, the irritating/harmful effects of smoking are greatly reduced or eliminated along with second hand smoke by using a vaporizer. This makes vaporizers useful in places where there are public bans on smoking.

The shortcomings of smoked cannabis have been widely viewed as a major obstacle for approval of 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 typically found vaporization superior to smoking. High-end vaporizers used with high grade cannabis containing elevated levels of THC have been found to eliminate inhalation of substantial portions of undesired compounds in a manner consistent enough for clinical trials. In comparison to other cannabis routes of administration such as ingestion, vaporization offers the advantages of inhaling THC: rapid onset, more direct delivery into the bloodstream, and the possibility to gradually increase delivery until the desired level is reached, in this manner enabling more effective self-dosage.

Types of Vaporizers

Vaporizers are available in many varieties.

Simple vaporizers use a lighter as heat source. There are two catagories of simple vaporisers, conduction and diffusion. Conduction such as http://eaglebill.com where the heat travels through the glass and diffusion invented by http://AmericanSmokeless (or http://TheUbie.Com) where it air mixed with sorrounding air to prevent combustion. Simple vaporizers are inexpencive and have expanded awareness of safer smoking alternitives.

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:

• by conduction
• by convection

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.

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. The modular Vaporization "Tools" or "System" approach 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 prior to delivery.

Health and Medical Use

Regardless of the benefits of medical cannabis, the widely perceived health risks of smoking as a route of administration have been viewed as a major obstacle for the legal approval of cannabis for medical uses, though some studies indicate that the expectorant activity of THC may help the lungs remove much of the inhaled tar through coughing. In response to the concerns, several studies have aimed to establish whether or not vaporizers could offer a clinically reliable and safe route of administration for cannabis. Though vaporizers show great variations in performance, such studies have consistently found vaporization superior to smoking and with best case (high-end vaporizers used with potent cannabis) results showing an elimination of undesired compounds suitable for clinical trials.

In comparison to other routes of administering cannabis such as eating, vaporization offers the advantages of inhalation - immediate delivery into the bloodstream, rapid onset of effect, and the ability to more accurately control the dosage in terms of its perceived effect.

Scientific Studies

At least four scientific studies have examined vaporizers. Studies have generally found the release of harmful constituents reduced or even completely eliminated, depending on vaporizer design. However, a 1996 study including two simple vaporizers still found ten times more tar in the vapor than THC, although this was nevertheless up to a 30% improvement compared to the best alternative smoking method.

In 2007, a study by University of California, San Francisco published in the Official Journal of the American Academy of Neurology examined the effectiveness of a vaporizer that heats cannabis to a temperature between 180 and 200 degrees (not all vaporizer types can achieve this degree of temperature control, and conclusions may therefore not apply to other types) and found:

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

A 2006 study, performed by researchers at Leiden University, tested a Volcano Vaporizer with preparations of pure THC and found that:

Our results show that with the Volcano 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 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 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 it delivered 36% - 61% of the THC in the sample - a more recent study using pure cannabinoid preparations achieved a maximum of 54%. For comparison, studies of cannabis cigarettes smoked via a smoking machine under varying conditions of puff duration and air speed found very similar efficiencies of 34% to 61%. Consequently, users can achieve the desired effect with a similar amount of material as when smoking.

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 tars 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 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 (joints). 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 more psychoactive THC than they do 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. A study by Donald Tashkin published in the American Review of Respiratory Disease found that, "the smoking of marijuana and ingestion of Delta 9-THC by subjects with chronic, clinically stable, bronchial asthma of minimal to moderate severity has been shown to produce airway dilatation of a magnitude similar to that previously noted in healthy subjects" , so it can be assumed that the coughing as a result of vaporizer usage is due to the vaporizer being turned up too high, thus producing smoke instead of vapor, or simply due to tracheobronchial irritation resulting from hot and dry vapors produced by most vaporizers. Becaues of this common problem overlooked in the design of most vaporizers that in effect are "dry delivery" based systems there has been a trend towards water conditioned and ice cooled vaporization systems, or modular systems, whereas the user can retro-fit an existing water pipe with a Vaporization Chamber Bowl that mates to a hot air gun.

Factors Affecting Vaporizer Efficiency

The wide range of results from tests of different vaporizers suggest that the choice of vaporizer is a major factor in determining delivery efficiency and the amount of harmful byproducts produced.

Proposed factors affecting output include:

• Vaporizer temperature
• Plant density
• Weight content of water and essential oils
• Consistency of plant material in the vaporizer
• Variety and potency of cannabis used
• Different preparations such as crude flowertops, hashish, hash oil, etc...
• Storage time of the vapor before inhalation
• Proportion of THC exhaled (breathing technique)

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 purest preparations produced the highest efficiencies, about 54% for pure THC versus 29% for plant material (female flowertops) with 12% THC content. Besides THC, several other cannabinoids as well as a range of other plant components including terpenoids were detected in the plant material. Using pure THC in the Volcano, no degradation products (delta-8-THC (D8-THC), cannabinol (CBN), or unknown compounds were detected by HPLC analysis.

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 University 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 scrapped and vaped for a potent effect, similar to kief.

Vaporizing For Enhanced Lung Capacity Technique

Although there are a multitude of ways in which to draw vapor from a vaporizer (and much will depend on the type/model of the vaporizer used) the technique used to absorb the maximum amount of THC is also the same way one would enhance lung capacity through exercise. The technique:

• 1.) Expel all air from lungs.
• 2.) Take very deep breath of air, filling from the abdomen up.
• 3.) Expel all air from lungs.
• 4.) Fill lungs to 2/3 their capacity from vaporizer, filling from the abdomen up, drawing from fast to slow
• 5.) Fill rest of lung with air and if applicable remove vaporizer from heat source, continuing to draw off of the vaporizer (in order to cool vaporizer, stopping vaporization when not in use).
• 6.) Hold breath a moment.
• 7.) Inhale one last bit of air.
• 8.) Hold breath a while (as long as comfortable/possible).
• 9.) Exhale slowly and controlled through the nose.

See also

• Health issues and the effects of cannabis

External links

• How to build a convection vaporizer
• How to build a conduction vaporizer
• Nearly all available Vaporizers
• About Eagle Bill, the vaporizer pioneer