Black tar heroin

Black tar heroin

Black tar heroin is a type of illicit opioid formed from the incomplete acetylation of morphine. It is also called black, brown, or simply tar.

Black tar can contain a variable percentage of heroin, but despite the name, what makes black tar specific as a type is not actually its heroin (diacetylmorphine) content, but rather the greater mixture of lesser acetylated morphine derivatives—predominantly 6-MAM (6-monoacetylmorphine) and 3-MAM (3-monoacetylmorphine). This is caused by the use of the antiquated Wright-Beckett process (c. 1874), which produces a relatively crude and unrefined opiate product but does not require the complex lab equipment, high-purity acetylating chemicals or lengthy reflux steps necessary to produce pure heroin, making it attractive to clandestine drug producers.^[1]

Black tar heroin is often produced in Latin America,^[2][3] and is most commonly found in the western and southern parts of the United States, while also being occasionally found in western Canada and Europe. It has a varying consistency depending on manufacturing methods, cutting agents, and moisture levels, ranging in quality from a black-brown, tarry goo in unrefined form to a uniform, light-brown powder when further processed and cut with lactose.

History

The process for synthesizing black tar heroin was discovered through the joint works of C. R. A. Wright and G. H. Beckett in 1874,^[4] while trying to synthesize gamma-monoacetylmorphine. Both believed they had succeeded in achieving their goal, but soon found that morphine has only two replaceable hydroxyls and that the original substance was theoretically impossible to synthesize under the conditions. Having learned this, the two men realized that they had stumbled upon the first successful synthesis of heroin (diacetylmorphine), as well as the two monoacetylmorphines, 6-MAM and 3-MAM. The following year, Wright and Beckett published their results in Journal of the Chemical Society.^[4]

By 1935, the pharmacological work of Eddy and Howes^[5] revealed that heroin is quickly hydrolyzed by the human body into 6-MAM, an easier to prepare and more stable substance. These results provided the impetus for attempts at deliberate synthesis of 6-MAM. It was between then and 1943 that 6-MAM started being used for recreation. The effects of unsanitary intradermal, intramuscular, and intravenous use made their way into American medical literature in 1943, with wound botulism being related to these methods.^[6]

Composition

Pure morphine and heroin are both fine powders. Tar's unique appearance and texture is due to its acetylation without benefit of the usual reflux apparatus: the Wright-Beckett process substitutes common acetic acid for high-purity acetic anhydride in the acetylating process and omits the refluxing steps, making black tar cruder but cheaper and faster to produce than true heroin. It should also be noted that the percent of the remainder of black tar heroin is often other psychoactive opiate substances, like monoacetylmorphine in the form of 3- and 6-monoacetylmorphine (3-MAM and 6-MAM) as well as the toxic 6-Monoacetylcodeine as well as the usual adulterants and diluents found in other forms of heroin.

The abnormally high 3-MAM content is due to the less than optimum acetylating agent combined with a different reaction time for the acetylation procedure. Varying levels of 6-MAM are due to the process of hydrolysis or from the process of using a catalyst in the creation of the product from the beginning (6-MAM being more potent by weight than 3,6-AM or "heroin" proper), a natural decomposition of heroin, which is accelerated when the heroin comes into contact with moisture. In 2006, ten-year-old samples of black tar heroin held as evidence were found to contain 51% and 63% 6-MAM by the Vista, California, U.S. DEA laboratory.^[7]

40 percent afghan heroin is equal to about 30 percent purity black tar. Most black tar heroin is between 55 and 93 percent purity . In black tar heroin the morphine is concentrated in liquid opium to approximately 90 percent purity. Instead of extracting the morphine from the opium, it is instead concentrated within the opium sap and acetylated as is. This is what gives it that gummy appearance.

The assumption that tar has less adulterants and diluents is a misconception. The most common adulterant is lactose, which is added to tar via dissolution of both substances in a liquid medium, reheating and filtering, and then recrystallizing. This process is very simple and can be accomplished in any kitchen with no level of expertise needed.

The price per kilogram of black tar heroin has increased from one-tenth that of South American powder heroin in the mid-1990s to between one-half and three-quarters in 2003 due to increased distributional acumen combined with increased demand in black tar's traditional realm of distribution. Black tar heroin distribution has steadily risen in recent years, while that of U.S. east coast powder varieties has dropped; heroin production in Colombia has decreased^[8] as U.S.-funded efforts to eradicate Colombian poppy fields continue.^[9]

Health effects

People who intravenously inject black tar heroin are at higher risk of venous sclerosis than those injecting powder heroin. In this condition, the veins narrow and harden which makes repeated injection there nearly impossible. Researchers at UC-San Francisco have found that the rapidity with which black tar heroin destroys veins, along with its gummier consistency, may put people who inject it at a lower risk of HIV infection because they may be forced to inject subcutaneously (rather than into veins), and needles must be thoroughly rinsed free of 'black tar' between injections if new sterilized ones are not available.^[10]

The presence of 6-monoacetylcodeine found in tar heroin has not been tested in humans but has been shown to be toxic alone and more toxic when mixed with mono- or di- acetyl morphine potentially making tar more toxic than refined diamorphine.

At least one study has drawn attention to lower rates of HIV infection amongst drug injectors in which black tar heroin is the major form of street-available heroin, suggesting that this may be due to the need to heat black tar heroin to dissolve it (which also inactivates any HIV present in the solution).^[11]

However, black tar heroin injectors can be at increased risk of life-threatening bacterial infections, in particular necrotizing soft tissue infection. The practice of "skin-popping" or subcutaneous injection predisposes to necrotizing fasciitis or necrotizing cellulitis from Clostridium perfringens, while deep intramuscular injection predisposes to necrotizing myositis. Tar heroin injection can also be associated with Clostridium botulinum infection.^[12]

Alternative routes of administration

In some parts of the United States, especially the lower states, black tar may be the only form of heroin that is available. Many users do not inject.

• Grinding into a powder form: This is one of the more popular ways of consuming black tar to those who do not wish to use needles. The black tar heroin is put into some sort of blender and mixed in with lactose. This creates a fine powder product that can be easily snorted.
• Water looping: Water looping is when a user places the heroin in an empty eye dropper bottle, or a syringe with the needle removed. The user allows the heroin to completely dissolve into water and the solution is dropped into the nose. This at times can be wasteful if a user allows too much of the solution to go down the throat.
• Vaporizing (Chasing the dragon): A user puts the heroin on a piece of foil and heats the foil with a lighter underneath it. The user uses a straw or similar apparatus and inhales the vapor.
• Drinking: This is less common due to the wastefulness, but it is done similar to the water looping method. Instead of being delivered through the nose, the solution is swallowed.
• Suppository: The most effective route of administration which does not require a needle, accomplished by delivering a solution (via syringe) or lubricated mass of the narcotic deep into the rectum or vagina. This can lead to internal bleeding.

References

External links

• National Drug Threat Assessment 2005, National Drug Intelligence Center. Accessed 15 December 2005
• Heroin, Interpol Drugs Sub-Directorate. Accessed 15 December 2005