Toxic Chemicals in Cigarettes

Man Smoking Cigarette While Relaxing On Bed
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The legal age limit is 21 for purchasing cigarettes, cigars, or any other tobacco products in the U.S.

If you smoke cigarettes or e-cigarettes, every puff puts poisons, toxic metals, and carcinogens into your bloodstream. In fact, of the more than 7,000 chemicals in cigarette smoke, at least 250 are dangerous to your health, and at least 69 of those can cause cancer. Whether you smoke cigarettes, use e-cigarettes (vape pens), or inhale secondhand smoke, those chemicals affect everything from your blood pressure and pulse rate to your organs and immune system.

Chemicals in Cigarettes

Air tainted with cigarette smoke is dangerous for anyone who breathes it. These are the chemicals that you are exposed to in cigarette smoke.


A carcinogen is defined as any substance that can cause or aggravate cancer. Approximately 70 of the chemicals in cigarettes are known to cause cancer. These include:

  • Acetaldehyde
  • Aromatic amines
  • Arsenic
  • Benzene
  • Beryllium (a toxic metal)
  • 1,3–Butadiene (a hazardous gas)
  • Cadmium (a toxic metal)
  • Chromium (a metallic element)
  • Cumene
  • Ethylene oxide
  • Formaldehyde
  • Nickel (a metallic element)
  • Polonium-210 (a radioactive chemical element)
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Tobacco-specific nitrosamines
  • Vinyl chloride

Toxic Metals

Toxic (heavy) metals are metals and metal compounds that have the potential to harm health when absorbed or inhaled. They're present in the soil and fertilizer used in growing tobacco. In very small amounts, some of these metals support life, but when inhaled in large amounts, they can become toxic. These include:

  • Arsenic. Commonly used in rat poison, it finds its way into cigarette smoke through pesticides used in tobacco farming.
  • Cadmium. This heavy metal is used in batteries. Smokers typically have twice as much cadmium in their bodies as nonsmokers.

Radioactive Toxic Metals

A couple of toxic metals in cigarette smoke carry extra danger for anyone breathing it in: They are radioactive. Lead-210 (Pb-210) and polonium-210 (Po-210) are poisonous, radioactive heavy metals present in cigarette smoke.


Poison is defined as any substance that, when introduced to a living organism, causes severe physical distress or death. Science has discovered approximately 250 poisonous gases in cigarette smoke. Here are a few you might recognize:

  • Ammonia compounds. Commonly used in cleaning products and fertilizers, ammonia is also used to boost the impact of nicotine in manufactured cigarettes.
  • Carbon monoxide. Present in car exhaust and lethal in large amounts, it's present at high levels in cigarette smoke.
  • Hydrogen cyanide. This was used to kill people in gas chambers during the Holocaust.
  • Nicotine. This poison used in pesticides is the addictive element in cigarettes.

Secondhand Smoke

Also known as environmental tobacco smoke, secondhand smoke is cigarette smoke that comes from two sources: smoke that is exhaled by a nearby smoker (mainstream smoke) and smoke produced by a nearby smoldering cigarette (sidestream smoke).

The National Toxicology Program estimates that secondhand smoke contains at least 250 poisonous chemicals and another 70 cancer-causing chemicals.

According to the U.S. Surgeon General, there is no risk-free level of exposure to secondhand smoke. If you can smell cigarette smoke, it could be harming your health.


E-cigarettes (aka vapes) contain many of the same chemicals as their combustible counterparts, and then some.

In a CDC study, 99% of the tested e-cigarettes contained nicotine. And not in small amounts: According to e-cigarette maker Juul, just one of its cartridges contains as much nicotine as a pack of 20 cigarettes.

In a 2021 study, Johns Hopkins University researchers uncovered almost 2,000 undisclosed chemicals in vaping aerosols, including six potentially harmful compounds—among them, a pesticide.

Furthermore, the liquid used in e-cigarettes, commonly known as "e-juice," contains many other flavorings and chemicals such as:

  • Solvent carriers (propylene glycol and glycerol)
  • Tobacco-specific nitrosamines (TSNAs)
  • Aldehydes
  • Metals
  • Volatile organic compounds (VOCs)
  • Phenolic compounds
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Tobacco alkaloids

Beginning in January 2020, the U.S. FDA banned the sale of prefilled cartridge e-cigarettes in any flavor other than tobacco or menthol, unless officially authorized.

If You're Still Smoking

It's never too late to start your journey to a smoke-free life. You'll be rewarded with benefits beyond what you can probably imagine—and they'll start to occur in as little as 20 minutes of your last cigarette, when your body begins healing.

Frequently Asked Questions

  • How many chemicals are in cigarettes?

    Cigarette smoke contains at least 700 chemicals—at least 250 of them harmful, and at least 69 carcinogenic.

  • How many chemicals are in e-cigarettes?

    In a 2021 study, Johns Hopkins University researchers uncovered almost 2,000 undisclosed chemicals in vaping aerosols, including six potentially harmful compounds—among them, a pesticide.

  • What cancer-causing chemicals are in cigarettes?

    Cigarette smoke contains at least 69 carcinogenic compounds, including arsenic, benzene, and polyvinyl chloride. They make up the more than 250 harmful chemicals in cigarettes.

  • Why are there so many chemicals in cigarettes?

    A tobacco plant absorbs many substances, such as cadmium and lead, from the soil it's grown in. Other chemicals known as tobacco-specific nitrosamines (TSNAs) form as tobacco leaves dry. Still more chemicals are added during the cigarette-manufacturing process to improve flavor and nicotine absorption.

8 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. Centers for Disease Control and Prevention. Chemistry and Toxicology of Cigarette Smoke and Biomarkers of Exposure and Harm. In: 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.

  2. Warren GW, Alberg AJ, Kraft AS, Cummings KM. The 2014 surgeon general’s report: “The health consequences of smoking-50 Years of progress”: A paradigm shift in cancer care: Surgeon general’s report and cancer careCancer. 2014;120(13):1914-1916. doi:10.1002/cncr.28695

  3. U.S. Department of Health and Human Services. How tobacco smoke causes disease: The biology and behavioral basis for smoking-attributable disease: A report of the Surgeon General. 2010.

  4. Jaishankar M, Tseten T, Anbalagan N, Mathew BB, Beeregowda KN. Toxicity, mechanism and health effects of some heavy metalsInterdiscip Toxicol. 2014;7(2):60-72. doi:10.2478/intox-2014-0009

  5. Seiler RL, Wiemels JL. Occurrence of ²¹⁰Po and biological effects of low-level exposure: the need for researchEnviron Health Perspect. 2012;120(9):1230-1237. doi:10.1289/ehp.1104607

  6. Tsai J, Homa DM, Gentzke AS, et al. Exposure to Secondhand Smoke Among Nonsmokers - United States, 1988-2014MMWR Morb Mortal Wkly Rep. 2018;67(48):1342-1346. doi:10.15585/mmwr.mm6748a3

  7. Marynak KL, Gammon DG, Rogers T, Coats EM, Singh T, King BA. Sales of nicotine-containing electronic cigarette products: United States, 2015Am J Public Health. 2017;107(5):702-705. doi:10.2105/AJPH.2017.303660

  8. Tehrani MW, Newmeyer MN, Rule AM, Prasse C. Characterizing the chemical landscape in commercial e-cigarette liquids and aerosols by liquid chromatography–high-resolution mass spectrometryChem Res Toxicol. 2021;34(10):2216-2226. doi:10.1021/acs.chemrestox.1c00253

Additional Reading

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