Cigarette Tar and How It Can Hurt You

The Toxic Chemicals in Cigarettes

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Cigarette tar is a term used to describe the toxic chemical particles left behind by burning cigarettes. This substance forms a tacky brown or yellow residue. It is not the same as tar used on road surfaces.

The tar in cigarette smoke paralyzes and can eventually kill cilia as it is inhaled into the lungs. Cilia are tiny, hair-like projections that line the trachea. They help to trap pollutants, but when they're disabled, toxins in tar can travel deeper into the lungs.

Some will be coughed back out, but some settle and stay in the lungs, where they can cause damage.

Cigarette tar causes yellow/brown staining of the teeth and contributes to gum disease and oral cancer.

Are "Light Cigarettes" Healthier?

Cigarette filters were first added to cigarettes in the 1950s when it was reported that the tar in cigarettes was associated with an increased risk of lung cancer. The idea was for the filter to trap harmful tar and nicotine residues, but the design never worked as well as hoped. Plenty of toxins still made it through and into the smoker's lungs, exposing them to the risks of smoking-related disease.

Today, "light," "low," and "mild" descriptors on cigarette labels are no longer allowed in the United States. Cigarettes with a lower level of tar are referred to as "low-yield" cigarettes. This was done so that smokers don't mistakenly think that these cigarette products are healthier than regular cigarettes.

Research has shown that the risk level for lung cancer in smokers is virtually the same regardless of whether regular or low yield cigarettes are smoked. Additionally, current smokers face a greater risk of lung cancer than never smokers or smokers who have quit, regardless of the tar level in their cigarettes.

Cigarette Tar and Third-hand Smoke

In recent years, science has identified additional risks associated with cigarette residue that lingers in closed environments where cigarettes (cigars, pipe and rolling tobacco, too) have been smoked. This health threat is called third-hand smoke.

Cigarette tar and third-hand smoke contain many of the same chemicals, and it is now understood that the brown, tacky toxins left behind from smoke drawn through cigarette filters also settles on surfaces and stays put.

In addition to the resins that make up cigarette tar, third-hand smoke also includes airborne chemicals that remain in the air for a period of time after a cigarette has been smoked.

Third-hand smoke is dangerous for everyone who comes in contact with it, but especially for small children who may touch tainted surfaces and then put fingers into their mouths.

Key Facts

  • Tar is present in any tobacco product that is burned.  The level of tar increases as the item is burnt down. The last puffs on a cigarette can contain as much as twice the amount of tar as the first puffs.
  • Tar is responsible for the brown stains on the fingers and teeth of smokers.
  • Tar in cigarette smoke paralyzes the cilia in the lungs and contributes to lung diseases such as emphysema, chronic bronchitis, and lung cancer.
  • In the past, the concentration of tar in a cigarette determined its rating: High-tar cigarettes (regular or full-flavor) contained 15 milligrams (mg) or more of tar. Medium-tar (light) cigarettes had 6-15 mg, and low-tar (extra-light or ultra-light) cigarettes contained 1-6 mg of tar.
  • The average amount of tar in cigarettes was lowered from 38 mg (and 2.7 mg for nicotine)  in 1954 to 12 mg of tar and 0.95 mg of nicotine. It remains at that level today.

Cigarette tar is poisonous and carcinogenic and is present wherever there is tobacco smoke. The best way to remove this danger from your life and those you love is to avoid indoor locations (including cars) where cigarettes are smoked, or quit if you're a smoker yourself.


British Medical Journal. The Fallacy of "Light" Cigarettes. Low Tar is Not Low Risk. March 13, 2004.

Centers for Disease Control and Prevention. Low Yield Cigarettes Updated December 1, 2016.

National Institutes of Health. Cigarette tar yield and risk of upper digestive tract cancers: case-control studies from Italy and Switzerland