Black tar heroin is a type of illicit opiate

Opiate

In medicine, the term opiate describes any of the narcotic opioid alkaloids found as natural products in the opium poppy plant.-Overview:Opiates are so named because they are constituents or derivatives of constituents found in opium, which is processed from the latex sap of the opium poppy,...

 narcotic drug formed from the incomplete acetylation

Acetylation

Acetylation describes a reaction that introduces an acetyl functional group into a chemical compound...

 of morphine

Morphine

Morphine is a potent opiate analgesic medication and is considered to be the prototypical opioid. It was first isolated in 1804 by Friedrich Sertürner, first distributed by same in 1817, and first commercially sold by Merck in 1827, which at the time was a single small chemists' shop. It was more...

. It is also called brown.

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

Reflux

Reflux is a technique involving the condensation of vapors and the return of this condensate to the system from which it originated. It is used in industrial and laboratory distillations...

 steps necessary to produce pure heroin, making it attractive to clandestine drug producers.

Black tar heroin is produced in Latin America

Latin America

Latin America is a region of the Americas where Romance languages  – particularly Spanish and Portuguese, and variably French – are primarily spoken. Latin America has an area of approximately 21,069,500 km² , almost 3.9% of the Earth's surface or 14.1% of its land surface area...

, 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

Lactose

Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...

.

History

The process for synthesizing black tar heroin was discovered through the joint works of C. R. A. Wright & G. H. Beckett in 1874, 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.

By 1935, the pharmacological work of Eddy & Howes 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

Botulism

Botulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...

 being related to these methods.

Composition

Pure morphine and heroin are both fine, white, and odorless 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

Acetic acid

Acetic acid is an organic compound with the chemical formula CH3CO2H . It is a colourless liquid that when undiluted is also called glacial acetic acid. Acetic acid is the main component of vinegar , and has a distinctive sour taste and pungent smell...

 for high-purity acetic anhydride

Acetic anhydride

Acetic anhydride, or ethanoic anhydride, is the chemical compound with the formula 2O. Commonly abbreviated Ac2O, it is the simplest isolatable acid anhydride and is a widely used reagent in organic synthesis...

 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

Monoacetylmorphine

6-Monoacetylmorphine or 6-Acetylmorphine is one of three active metabolites of heroin , the others being morphine and the much less active 3-Monoacetylmorphine ....

 in the form of 3- and 6-monoacetylmorphine (3-MAM and 6-MAM) in addition to 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

Hydrolysis

Hydrolysis is a chemical reaction during which molecules of water are split into hydrogen cations and hydroxide anions in the process of a chemical mechanism. It is the type of reaction that is used to break down certain polymers, especially those made by condensation polymerization...

 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-DAM 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

Drug Enforcement Administration

The Drug Enforcement Administration is a federal law enforcement agency under the United States Department of Justice, tasked with combating drug smuggling and use within the United States...

 laboratory.

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 as U.S.-funded efforts to eradicate Colombian poppy fields continue.

Health matters specific to injecting black tar heroin

Users who intravenously inject

Intravenous therapy

Intravenous therapy or IV therapy is the infusion of liquid substances directly into a vein. The word intravenous simply means "within a vein". Therapies administered intravenously are often called specialty pharmaceuticals...

 black tar heroin are at higher risk of venous sclerosis

Atherosclerosis

Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

 (a condition where the veins narrow and harden, making injection there nearly impossible) than users of powder heroin. Researchers at UC-San Francisco

University of California, San Francisco

The University of California, San Francisco is one of the world's leading centers of health sciences research, patient care, and education. UCSF's medical, pharmacy, dentistry, nursing, and graduate schools are among the top health science professional schools in the world...

 have found that the rapidity with which black tar heroin destroys veins (forcing users to inject subcutaneously

Subcutaneous injection

A subcutaneous injection is administered as a bolus into the subcutis, the layer of skin directly below the dermis and epidermis, collectively referred to as the...

), along with its gummier consistency (requiring that needles be thoroughly rinsed between use, in case new, sterilized ones are not available during usage), may put users at a lower risk of HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

 infection.

Users of black tar heroin are 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

Necrotizing fasciitis

Necrotizing fasciitis , commonly known as flesh-eating disease or Flesh-eating bacteria syndrome, is a rare infection of the deeper layers of skin and subcutaneous tissues, easily spreading across the fascial plane within the subcutaneous tissue.Necrotizing fasciitis is a quickly progressing and...

 or necrotizing cellulitis from Clostridium perfringens

Clostridium perfringens

Clostridium perfringens is a Gram-positive, rod-shaped, anaerobic, spore-forming bacterium of the genus Clostridium. C. perfringens is ever present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates,...

, while deep intramuscular injection predisposes to necrotizing myositis. It can also be associated with Clostridium botulinum

Clostridium botulinum

Clostridium botulinum is a Gram-positive, rod-shaped bacterium that produces several toxins. The best known are its neurotoxins, subdivided in types A-G, that cause the flaccid muscular paralysis seen in botulism. It is also the main paralytic agent in botox. C. botulinum is an anaerobic...

.

Conversely, at least one study has drawn attention to lower rates of HIV infection among injecting drug users in areas 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).

Terminology

Users of "Black tar heroin" do not typically refer to it as such, it rather has an abundance of street names that differ from region to scene; most other names used for other varieties of heroin are also shared for black tar among its users, regardless of whatever differing chemistry there is between the substances.

Common colloquialisms for Black Tar Heroin:

Brown Black Slab Pigment The letter "S" or "P"

Tar Chiva Mexican Mud Garga

BTH La Negra Hop Niff

Documentary

The lifestyles of users are captured on the 1999 documentary Black Tar Heroin: The Dark End of the Street

Black Tar Heroin (film)

Black Tar Heroin: The Dark End of the Street is a 1999 documentary directed by Steven Okazaki. Filmed from 1995 to 1998 in the Tenderloin, San Francisco, California, the documentary describes the lives of heroin addicts.-Overview:...

.

External links

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