How Tar in Cigarettes Can Hurt You

Stack of cigarettes, one with a stained filter

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As of Dec. 20, 2019, the new legal age limit is 21 years old for purchasing cigarettes, cigars, or any other tobacco products in the U.S.

Tar is a chemical substance that is produced when tobacco is burned. It is the tar in cigarettes that contains most of the cancer-causing chemicals in tobacco smoke. When inhaled, this tar can have a damaging effect on the lungs and contribute to serious health problems.

This article discusses the health risks associated with tar in cigarettes. It also covers the risks of "light" cigarettes, secondhand smoke, e-cigarettes, and thirdhand smoke.

What Is Tar in Cigarettes?

Cigarette tar is a term used to describe the toxic chemical particles left behind by burning tobacco. This substance forms a tacky brown or yellow residue. It is not the same as tar used on road surfaces. Tobacco is best known for three major dangers:

Nicotine is the addictive chemical in cigarettes but it is the tar that is responsible for the biggest health risks, including many types of cancer.

Facts About Tar

  • 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 in cigarette smoke paralyzes the cilia in the lungs and contributes to lung diseases such as emphysema, chronic bronchitis, and lung cancer.
  • The average amount of tar in cigarettes was lowered from 38 milligrams (mg) and 2.7 mg of nicotine in 1954 to 12 mg of tar and 0.95 mg of nicotine. It remains at that level today.

Cigarette Tar Health Risks

According to the National Cancer Institute (NCI), tobacco smoke contains over 7,000 chemicals. The majority are found in the tar produced by smoking cigarettes.

Two hundred fifty of those chemicals—including carbon monoxide, ammonia, and hydrogen cyanide—are known to be harmful to smokers and people exposed to secondhand smoke. Of those, at least 70 are known to cause cancer.

Impact on the Lungs

The tar in cigarette smoke builds up inside the lungs as it is inhaled. Over time, healthy pink lung tissue turns grey and eventually becomes black as more tar accumulates.

The primary effect is that the tar paralyzes and can eventually kill cilia in the airways. Cilia are tiny, hair-like structures that line the trachea. They help trap pollutants, but when they're damaged, the toxins in tar can travel deeper into the lungs.

Some of these toxins are released when you exhale or are coughed back out, but some settle and stay in the lungs. Eventually, this can lead to lung disease and conditions such as emphysema, bronchitis, and lung cancer.

Risk of Cancer

The tar does not just affect your lungs, though. From there, the toxins can be carried into the bloodstream and begin moving to other parts of your body. Because smoke is drawn directly through the mouth, the tar can contribute to oral cancer as well.

Effects on the Brain

Smoking has been shown to have negative effects on the brain, but it isn't just smokers themselves who are affected. Research has also found that even limited exposure to the chemicals in secondhand smoke leads to changes in the brain.

Such changes may increase the vulnerability to nicotine addiction in people who are exposed to secondhand smoke.

Some research also indicates that the chemicals in cigarettes may be linked to other cognitive effects. These include deficits in learning, memory, executive skills, processing speed, and general intelligence.

Other Health Conditions

Toxins from tar can affect every organ in your body. Beyond cancer, tar toxins can lead to yellow-brown staining on smokers' fingers and teeth as well as the following health conditions:

What About Light Cigarettes?

Cigarette filters were first added in the 1950s when it was reported that the tar in tobacco 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.

The concentration of tar in a cigarette was what determined its rating:

  • High-tar cigarettes (regular or full-flavor) contained 15 mg or more of tar. 
  • Medium-tar (light) cigarettes had 6 mg to 15 mg of tar.
  • Low-tar (extra-light or ultra-light) cigarettes contained 1 mg to 6 mg of tar.

In 2009, the Family Smoking Prevention and Tobacco Control Act was passed to prohibit the manufacture, sale, and distribution of any tobacco products labeled as "light," "low," or "mild" on their labels.

Cigarettes with a lower level of tar are referred to as "low-yield" cigarettes but are not less harmful. This was done so that smokers don't mistakenly think that these cigarette products are healthier than regular cigarettes.

The filters in low-yield cigarettes also have more air holes than typical filters. This does not seem to do much good because many smokers inadvertently cover them up when holding a cigarette.

According to NCI, 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.

Quite often, smokers will inhale more deeply and smoke more low-yield cigarettes to obtain the same amount of nicotine found in regular cigarettes. Additionally, current smokers face a greater risk of lung cancer than people who have never smoked or smokers who have quit, regardless of the tar level in their cigarettes.

Do E-Cigarettes Contain Tar?

Because e-cigarettes do not contain tobacco, they do not contain tar. However, the FDA still considers these to be "tobacco products." While they do not contain tar, they carry risks of their own. They do contain nicotine as well as other substances that can cause cancer, lung disease, and heart disease.

More research is needed to understand the long-term effects of e-cigarettes, but these devices have been linked to cases of severe lung disease.

Cigarette Tar and Thirdhand Smoke

Over the years, there has been a lot of talk about secondhand smoke. Being in an environment with smokers has been proven to lead to a number of diseases and even cause strokes in some non-smokers. That is not the only harm, though.

Scientists have identified additional risks associated with cigarette residue that lingers in closed environments where cigarettes, cigars, pipes, and rolling tobacco have been smoked. This health threat is called thirdhand smoke.

Cigarette tar and thirdhand smoke contain many of the same chemicals. 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, thirdhand smoke also includes airborne chemicals that remain in the air for a period of time after a cigarette has been smoked.

Thirdhand smoke is dangerous for everyone who comes in contact with it. It is especially harmful to small children who may touch tainted surfaces and then put fingers into their mouths.

Quitting Resources

If you are ready to quit smoking, there are resources available that can help. It can be helpful to understand that quitting can take time and there may be setbacks along the way.

Around 40% of people who quit smoking successfully had to try more than once before they were able to give up smoking.

You can improve your chances for success by learning more about the symptoms of withdrawal you might experience and taking steps to find relief. There are also smoking cessation medications and nicotine replacement therapy (NRT) options that can improve your chances of quitting and help minimize withdrawal symptoms.

Having a quit smoking plan and seeking social support can also help you on your journey. It may not be easy, but remember that you are not alone. 

A Word From Verywell

Cigarette tar is poisonous and carcinogenic and is present wherever there is tobacco smoke. The best way to remove this danger from your life is to avoid indoor locations (including cars) where cigarettes are smoked.

If you are a smoker yourself, consider stopping. When you're ready, there are a variety of resources available to help you on the journey to quit smoking.

Frequently Asked Questions

  • Why is there tar in cigarettes?

    Tar is produced when tobacco is burned. It is a natural product of the combustion of the plant materials in cigarettes.

  • How much tar is in a pack of cigarettes?

    While it varies depending on the product, the average amount may range between 6 mg to 15 mg per cigarette. With 20 cigarettes in a pack, this would mean a pack of cigarettes contains between 120 mg and 300 mg of tar.

  • How much tar is in weed compared to cigarettes?

    According to the National Institute on Drug Abuse, smoking marijuana deposits four times the amount of tar in the lungs as cigarettes. The American Lung Association suggests that this is because marijuana smokers tend to inhale more deeply and hold their breath longer, which increases exposure to tar.

  • What does the tar in cigarettes do to your body?

    The tar in cigarettes paralyzes the tiny, hair-like cilia that help remove pollutants from the lungs. This traps the damaging substances from cigarettes in the lungs, contributing the conditions such as lung cancer, bronchitis, and emphysema.

16 Sources
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Lee PN. Tar level of cigarettes smoked and risk of smoking-related diseases. Inhal Toxicol. 2018;30(1):5-18. doi:10.1080/08958378.2018.1443174

  2. Centers for Disease Control and Prevention. Low-yield cigarettes.

  3. National Cancer Institute. Harms of cigarette smoking and health benefits of quitting.

  4. Centers for Disease Control and Prevention (US); National Center for Chronic Disease Prevention and Health Promotion (US); Office on Smoking and Health (US). How Tobacco Smoke Causes Disease: The Biology and Behavioral Basis for Smoking-Attributable Disease: A Report of the Surgeon General. Atlanta, GA: Centers for Disease Control and Prevention (US); 2010.

  5. Centers for Disease Control and Prevention. Cigarette smoking and radiation.

  6. Tilley AE, Walters MS, Shaykhiev R, Crystal RG. Cilia dysfunction in lung diseaseAnnu Rev Physiol. 2015;77:379-406. doi:10.1146/annurev-physiol-021014-071931

  7. Gautam DK, Jindal V, Gupta SC, Tuli A, Kotwal B, Thakur R. Effect of cigarette smoking on the periodontal health status: A comparative, cross sectional studyJ Indian Soc Periodontol. 2011;15(4):383-387. doi:10.4103/0972-124X.92575

  8. Brody AL, Mandelkern MA, London ED, Khan A, Kozman D, Costello MR, Vellios EE, Archie MM, Bascom R, Mukhin AG. Effect of secondhand smoke on occupancy of nicotinic acetylcholine receptors in brain. Arch Gen Psychiatry. 2011;68(9):953-60. doi:10.1001/archgenpsychiatry.2011.51

  9. Valentine G, Sofuoglu M. Cognitive effects of nicotine: Recent progressCurr Neuropharmacol. 2018;16(4):403-414. doi:10.2174/1570159X15666171103152136

  10. National Cancer Institute. Risks Associated with Smoking Cigarettes with Low Machine-Measured Yields of Tar and Nicotine, Smoking and Tobacco Control Monograph No 13. Bethesda, MD: U.S. Department of Health and Human Services, Public Health Service, National Institutes of Health, National Cancer Institute; 2001.

  11. American Cancer Society. Is any type of tobacco product safe?

  12. American Cancer Society. What do we know about e-cigarettes?

  13. Acuff L, Fristoe K, Hamblen J, Smith M, Chen J. Third-hand smoke: Old smoke, new concerns. J Community Health. 2016;41(3):680-7. doi:10.1007/s10900-015-0114-1

  14. Centers for Disease Control and Prevention. Health effects of cigarette smoking.

  15. National Institute on Drug Abuse. What are marijuana's effects on lung health?

  16. American Lung Association. Marijuana and lung health.

By Terry Martin
Terry Martin quit smoking after 26 years and is now an advocate for those seeking freedom from nicotine addiction.