You probably know that cigarette smoking kills you. You probably know that cigarettes contain chemicals—a mix of over 7,000 chemicals, in fact—that can cause diseases including cancer, cardiovascular disease, and COPD.1 You may not know that other tobacco products, like e-cigarettes, hookah, and smokeless tobacco, contain some of the same chemicals as cigarettes. What are these chemicals, and how might they affect your health?
Nicotine: The Addictive Chemical in Tobacco
Nicotine is a highly addictive chemical found in the tobacco plant itself and is therefore present in all tobacco products. While nicotine is what addicts and keeps people using tobacco products, it is not what makes tobacco use so deadly. Tobacco and tobacco smoke contain thousands of chemicals. This mix of chemicals—not nicotine—is what causes serious disease and death in tobacco users.2
Chemicals in Cigarettes: How Do They Get There?
You may believe that cigarettes are so deadly because chemicals are added to them in the manufacturing process. While some chemicals are added during this process, some chemicals in cigarettes—along with nicotine—are found in the tobacco plant itself. As the tobacco plant grows, it absorbs chemicals—like cadmium, lead, and nitrates—from the soil and fertilizer.3,4 Cadmium is a carcinogen and is also found in batteries, while lead is a chemical that was once used in house paint. Cadmium and lead are both toxic metals.1 When the plant is harvested for manufacturing, these chemicals are present in the tobacco leaves.
As the tobacco leaves are cured, dangerous chemicals can form. These chemicals, called tobacco-specific nitrosamines, (TSNAs), remain in the tobacco leaves after the curing process.4,5,6 During manufacturing, ammonia—a chemical found in household cleaning products—along with other chemicals may be added to increase nicotine absorption.4,7 Sugar and flavor additives may also be added during this stage to mask the harshness of smoke. These additives form cancer-causing chemicals when they are burned.4,7,8
Once a cigarette is lit, still more chemicals are formed in the burning process that weren’t present in the growing and manufacturing stages. These chemicals are then inhaled by smokers or those exposed to secondhand smoke. Lastly, dangerous chemicals that are detrimental to human health, wildlife, and water supplies can be released from cigarette butt waste into the environment.9
Chemicals in Other Tobacco Products
In addition to nicotine, other tobacco products, like hookah, contain some of the same chemicals as cigarettes. Carbon monoxide, metals, and carcinogens can be found in hookah smoke, and hookah users are at risk for some of the same health effects as smokers as a result of these chemicals.10,11 Research shows that hookah smokers may absorb even more of the toxic chemicals found in cigarette smoke because of the length of hookah smoking sessions.11 A typical 1-hour hookah session can produce as much smoke as several packs of cigarettes.
Smokeless tobacco, although not combustible, contains a mix of 4,000 chemicals, including as many as 30 or more that are linked to cancer.12
These chemicals include heavy metals cadmium, lead, and nickel; as well as arsenic, a chemical used in insecticides; formaldehyde, which is used in embalming fluid; and N-Nitrosonornicotine (NNN), among others.13 NNN is known to cause cancer in animals and has been linked to an increase in the risk of cancer among humans.14,15
About 1,300 people in the U.S. are diagnosed with oral cancer each year because of smokeless tobacco use. Smokeless tobacco use also causes esophageal and pancreatic cancer.16-21
As e-cigarettes have only recently come under FDA’s regulatory authority, their effects on individual and population health are still being studied. Preliminary studies suggest switching completely to e-cigarettes could be less harmful than combustible cigarettes for adults who already have a nicotine addiction.22 Most e-cigarettes contain nicotine, the same highly addictive chemical in cigarettes that keeps people smoking even when they want to quit. Other chemicals found in cigarette smoke, like formaldehyde, acrolein, and acetaldehyde, are also found in some e-cigarette aerosols. These chemicals can cause irreversible lung damage at certain concentration.22-26 E-cigarettes can also contain flavorings such as diacetyl and acetoin. Diacetyl and acetoin are considered safe to eat but inhaling them can be harmful to the lungs.27 More research is needed to determine the levels at which these chemicals are present in e-cigarette aerosols.
Tobacco-Free: The Best Option for Health
Because all tobacco products contain the addictive chemical nicotine, no tobacco product can be considered safe. Using no tobacco products whatsoever is the best way to safeguard your health. But if you are an adult with an established addiction, cessation will help protect you from the chemicals in tobacco products and tobacco smoke. Quitting smoking is often difficult, and may take multiple attempts,28 but the longer a smoker is able to stay quit, the more of a chance the body gets to heal from the damage done from chemicals. Nicotine replacement therapies (NRTs) can be effective for cessation and can double your chances of quitting successfully.29 Although nicotine is an addictive chemical, it does not carry the same risks as some of the other chemicals found in tobacco products. Many FDA-approved NRTs, including gum, patches, and lozenges, are available without a prescription, and may be used in combination with each other.30 If you are an adult smoker and you are looking to quit, it is a good idea to talk to your doctor about your options.
FDA’s HPHC List
The chemicals and chemical compounds found in tobacco products or tobacco smoke that could cause harm to both smokers or, secondhand to nonsmokers, are called harmful and potentially harmful constituents (HPHCs). Manufacturers and importers are required to report the levels of HPHCs in their products to FDA. If you would like to learn more about HPHCs found in tobacco products and tobacco smoke, a preliminary list of 93 HPHCs linked to cancer, cardiovascular disease, respiratory conditions, reproductive problems, and addiction can be found here.
- Harmful and Potentially Harmful Constituents
- Nicotine: The Addictive Chemical in Tobacco Products
- Chemicals in Cigarettes: From Plant to Product to Puff
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2. U.S. Department of Health and Human Services (USDHHS). The Health Consequences of Smoking—50 Years of Progress: A Report of the Surgeon General. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2014.
3. Stephens WE, Calder A, Newton J. Source and health implications of high toxic metal concentrations in illicit tobacco products. Environmental Science & Technology. 2005; 39(2):479-488.
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11. Centers for Disease Control and Prevention (CDC). Smoking & Tobacco Use: Hookahs (Fact Sheet). http://www.cdc.gov/tobacco/data_statistics/fact_sheets/tobacco_industry/hookahs/. Updated December 17, 2013. Accessed August 18, 2014.
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14. International Agency for Research on Cancer (IARC). Smokeless Tobacco and Some Tobacco-Specific N-Nitrosamines. Lyon, France: World Health Organization, International Agency for Research on Cancer; 2007.
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16. Food and Drug Administration (FDA). Tobacco Product Standard for N-Nitrosonornicotine Level in Finished Smokeless Tobacco. Federal Register. 2017; 82(3): 8004-8053.
17. U.S. Department of Health and Human Services (USDHHS). The Health Consequences of Using Smokeless Tobacco—A Report of the Advisory Committee to the Surgeon General. Bethesda, MD: U.S. Department of Health and Human Services, National Institute of Health, 1986.
18. International Agency for Research on Cancer (IARC). Smokeless Tobacco and Some Tobacco-Specific N-Nitrosamines. Lyon, France. World Health Organization, International Agency for Research on Cancer; 2007.
19. European Commission, Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR). Health Effects of Smokeless Tobacco Products. Brussels, Belgium. European Commission; 2008.
20. International Agency for Research on Cancer (IARC). Personal Habits and Indoor Combustions: A Review of Human Carcinogens. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Vol. 100E. Lyon, France: International Agency for Research on Cancer; 2012.
21. National Cancer Institute (NCI), Centers for Disease Control and Prevention (CDC). Smokeless Tobacco and Public Health: A Global Perspective. Bethesda, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention and National Institutes of Health, National Cancer Institute. NIH Publication No. 14-7983; 2014.
22. National Academies of Sciences, Engineering, and Medicine. 2018. Public Health Consequences of E-Cigarettes. Washington, DC: The National Academies Press.
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24. Cheng T. Chemical evaluation of electronic cigarettes. Tobacco Control. 2014; 23:ii11–ii17.
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26. Occupational Safety and Health Administration (OSHA). Occupational Safety and Health Standards. Medical surveillance – Formaldehyde. Washington, DC: U.S. Department of Labor, Occupational Safety and Health Administration. https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10078. Accessed May 8, 2018.
27. Allen J, Flanigan SS, LeBlanc M, et al. Flavoring chemicals in e-cigarettes: Diacetyl, 2,3-pentanedione, and acetoin in a sample of 51 products, including fruit-, candy-, cocktail- flavored e-cigarettes. Environ Health Perspect. 2016;124. https://ehp.niehs.nih.gov/15-10185/. Accessed March 27, 2018.
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