The remainder could be sugars, starch, powdered milk, or quinine. The color and consistency of black tar heroin results from the crude processing methods used to illicitly manufacture the substance in Mexico. Black tar heroin may be sticky, like roofing tar or hard like coal, and its color may vary from dark brown to black. It is often sold on the street in its tar-like state at purities ranging from twenty to eighty percent. This heroin is most frequently dissolved, diluted and injected.
Injection is the most practical and efficient way to administer low-purity heroin.
The availability of higher purity heroin has meant that users now can snort or smoke the narcotic. Evidence suggests that heroin snorting is widespread or increasing in those areas of the country where high-purity heroin is available, generally in the northeastern United States.