A crack pipe works by applying heat to the outside of a glass tube, which melts and vaporizes crack cocaine held inside on a small mesh screen. The user inhales the resulting vapor through the tube into their lungs, where it crosses into the bloodstream and reaches the brain in roughly 6 to 8 seconds. The device is simple, but the chemistry behind why it works with crack and not powder cocaine, and the health consequences of using it, are worth understanding in detail.
Why Crack Can Be Smoked but Powder Cocaine Cannot
The distinction comes down to chemistry. Powder cocaine is a salt form (cocaine hydrochloride) with a melting point of 190 to 195 degrees Celsius. When heated, it simply burns and destroys nearly all of its psychoactive properties before ever becoming a vapor. Crack cocaine is the “base” form, created by chemically removing the salt. This base form has a much lower melting point of 89 to 92 degrees Celsius and converts directly from a solid to a vapor when heated, a process called sublimation. That property is what makes it smokable.
The efficiency of this vaporization depends on temperature. At around 170°C, roughly 73% of the cocaine in a crack rock successfully converts to inhalable vapor. Pushing the temperature above 225°C actually lowers that efficiency because the heat breaks cocaine molecules down into byproducts, primarily a compound called methylecgonidine, rather than preserving the drug in vapor form.
Parts of the Pipe
The most common crack pipe is a straight glass tube, typically made of Pyrex (borosilicate glass). Borosilicate glass can withstand temperature swings of about 165°C without cracking, which matters because the pipe is repeatedly heated and cooled during use. Cheaper soda-lime glass shatters easily under these conditions, which is a significant injury risk.
At one end of the tube, the user pushes in a small piece of brass screen or steel wool, shaped by hand into a plug. This screen serves two purposes: it holds the crack rock in place so it doesn’t fall into the tube, and it filters out solid particles, burning debris, and fragments of the rock that haven’t fully vaporized. Without a screen, the user would inhale hot, unvaporized chunks that can burn and cut the lips, mouth, throat, and airways. Brass screens originally designed for tobacco pipes have been repurposed for this role.
Some users attach a rubber mouthpiece, a short tube about four inches long, to the opposite end. This prevents the lips from touching the hot glass directly and reduces the risk of burns and sores.
How Heating and Inhalation Work
The user places a small piece of crack on the mesh screen and holds a flame, usually from a butane lighter, underneath or near the outside of the glass tube. The heat passes through the glass and melts the crack, which then releases vapor inside the tube. The user inhales through the open end, drawing the vapor through the length of the tube and into the lungs.
This is not combustion in the way cigarette smoking works. The goal is to vaporize the drug at a controlled temperature rather than set it on fire. In practice, though, the flame temperature far exceeds the ideal range, so some of the cocaine degrades into byproducts and some residue (called “resin”) deposits along the inside of the glass tube. Users often scrape or reheat this residue later.
What Happens After Inhalation
Cocaine vapor enters the lungs and passes through the thin walls of the air sacs directly into the bloodstream. Because the lungs have an enormous surface area and rich blood supply, this route delivers cocaine to the brain in about 6 to 8 seconds. Peak plasma concentration occurs within 5 minutes, comparable to intravenous injection. By contrast, snorting powder cocaine takes roughly 50 minutes to reach peak blood levels.
The peak stimulant effects hit within 1 to 3 minutes and last only 5 to 15 minutes. This short, intense cycle is a core reason the drug is associated with compulsive redosing: the high fades quickly, pushing the user to smoke again almost immediately.
Damage to the Mouth and Throat
The vapor temperature and the pipe itself cause direct physical injury. The two major threats to the upper airway are thermal burns from the hot vapor and trauma from the metal screen. In a clinical study examining patients who smoked crack, 67% had injuries above the vocal cords (the supraglottic area), 33% had damage to the back of the mouth and throat, and 17% had injuries to the lower throat. Documented findings include swelling of the epiglottis, the folds around the vocal cords, and impaired vocal cord movement.
Hot or broken glass tubes also cause cuts and burns on the lips. These open wounds become a route for transmitting infections when pipes are shared, which is extremely common. In one study of crack users in British Columbia, 80% had shared a pipe in the previous 30 days, and 44% had shared on more than 20 occasions in that time.
Lung Injury From Inhaled Vapor
“Crack lung” is an acute syndrome that can develop within 48 hours of smoking. It involves widespread damage to the air sacs in the lungs, including hemorrhage and inflammation. Symptoms include difficulty breathing, fever, cough, and coughing up blood, which can progress to respiratory failure. Chest imaging typically shows diffuse hazy patches across both lungs.
The mechanisms behind this damage are layered. The hot vapor directly burns airway tissue. Cocaine itself is toxic to lung cells. The drug triggers an inflammatory response in the lungs and causes blood vessels to constrict, which cuts off oxygen supply to surrounding tissue. The act of holding in a deep breath to maximize absorption also creates pressure-related injury (barotrauma) in the delicate air sacs.
Infection Risk From Shared Equipment
Hepatitis C virus has been detected on crack pipes. The transmission pathway works through the oral injuries that smoking causes: cuts from broken glass, burns from hot metal and glass, and sores on the lips all create openings where blood-borne viruses can enter. When one person with bleeding lips uses a pipe and passes it to another person who also has open sores, the virus can transfer.
In the British Columbia study, nearly half of the crack users examined tested positive for hepatitis C antibodies. Of 51 crack pipes tested, one was positive for the virus. Nearly half of participants were making pipes from improvised materials like pop cans, glass bottles, or inhalers, which lack smooth edges and increase the likelihood of cuts.
Using a personal mouthpiece and avoiding shared pipes reduces this risk. Harm reduction programs distribute rubber mouthpieces, brass screens, and Pyrex stems specifically to minimize burns, cuts, and exposure to blood-borne infections.