Crack (sometimes called crack-co-caine) is an illicit drug, the smokable form of CO-CAINE, made by adding the bases ammonia or baking soda and water to cocaine hydrochloride. The white powder illicitly purchased as cocaine is in the hydrochloride form; it cannot be smoked, because it is destroyed at the temperatures required for smoking. Therefore, in order to be used by the smoked route, cocaine must be converted to the base state. A mixture is made and heated to remove the hydrochloride, resulting in a pellet-sized cake-like solid substance that can be smoked. This form of cocaine is inexpensive, available for purchase "on the street," and is called "crack," because of the cracks formed in the solid as it dries.

Although crackcan be smoked in tobacco cigarettes or marijuana cigarettes, it is generally smoked in a special crack pipe. In its simplest form, this is a glass tube with...