Laura Gottschalk, PhD, John-Anthony Fraga, Jared Hirschfield, Diana Zuckerman, PhD, National Center for Health Research

Electronic cigarettes, or e-cigarettes, Electronic Cigarette Smoking are being marketed as the "safe" new alternative to conventional cigarettes. By February 2020, reports of 68 deaths and more than 2,800 vaping-related hospitalizations due to lung illnesses have made it clear that vaping can be even more dangerous than smoking.1,2

The CDC has reported that Vitamin E acetate is a potential cause for the outbreak, but it might not be the only one.2 Many of the patients report vaping marijuana products or marijuana and nicotine products, but others only vaped nicotine products. Until these reports of hospitalized teens and adults are scrutinized in greater depth, we won't know what types of vaping are most dangerous and under what circumstances.

E-cigarettes come in a variety of forms and include vape mods, Juuls, and vape pens. There are brand name products (Juul is the most widely used) and "home-made" versions.  Some contain high levels of nicotine, while others contain marijuana or just contain flavoring.  The focus of this article is on e-cigarettes because most of the research that exists has been done on them, but much of the information below is relevant to these other products as well.

The big questions are: Are they safe?  Will they reverse the decline in smoking—giving new life to an old habit—or can they help people quit smoking?  Here is what you need to know.

What are E-cigarettes?

E-cigarettes are battery-operated devices that were initially shaped like cigarettes, but now include vape mods, Juuls, and vape pens. Some look like flash drives or highlighter pens, making it easy for teens to hide them in plain sight.  The brand-name products contain nicotine, an addictive drug that is naturally found in tobacco and that stimulates, causes stress during withdrawal, and then feels relaxing as continued exposure follows withdrawal. It is the nicotine in cigarettes that makes smoking so addictive, and the same is true for most vaping and juuling. These electronic products allow nicotine to be inhaled, and they work by heating a liquid cartridge containing nicotine, flavors, and other chemicals into a vapor. Because e-cigarettes heat a liquid instead of tobacco, what is released is considered smokeless.3

Is Vaping Safer than Smoking Traditional Cigarettes?

The key difference between traditional cigarettes and e-cigarettes and related products is that the latter don't contain tobacco. But, it isn't just the tobacco in cigarettes that causes cancer and other serious diseases. Traditional cigarettes contain a laundry list of chemicals that are proven harmful, and e-cigarettes have some of these same chemicals.

While smoking can cause lung cancer, breast cancer, emphysema, heart disease, and other serious diseases, those diseases usually develop after decades of smoking. In contrast, in 2019 it became clear that vaping could cause seizures and serious lung damage after just a year, possibly less, based on CDC reports of patients hospitalized for lung damage caused by vaping.2,3 While there have been warnings about the possible risk of e-cigarettes for a decade, it was not expected that they could cause such severe damage in such a short period of time.

Some e-cigarette users also smoke marijuana and/or conventional cigarettes, and it is important to know if e-cigarette use alone can lead to breathing problems, independently of other types of smoking. A survey of almost 3,000 teens and young adults found that even when statistically controlling for whether they also smoking marijuana or conventional cigarettes, those who reported e-cigarette use in the last 30 days were statistically significantly more likely than non e-cigarette users to report problems with wheezing and shortness of breath.4

The COVID-19 pandemic has raised even more concerns about the safety of vaping. Youths aged 13-24 years old who have used e-cigarettes are more likely to be diagnosed with COVID-19, be tested for the virus, and to experience C OVID -19 symptoms. 5

Since 2009, FDA has pointed out that e-cigarettes contain "detectable levels of known carcinogens and toxic chemicals to which users could be exposed." For example, in e-cigarette cartridges marketed as "tobacco-free," the FDA detected a toxic compound found in antifreeze, tobacco-specific compounds that have been shown to cause cancer in humans, and other toxic tobacco-specific impurities.6 Another study looked at 42 of these liquid cartridges and determined that they contained formaldehyde, a chemical known to cause cancer in humans.7 Formaldehyde was found in several of the cartridges at levels much higher than the maximum EPA recommends for humans. In 2017, a study published in the Public Library of Science Journal showed that significant levels of benzene, a well-known carcinogen, were found in the vapor produced by several popular brands of e-cigarettes.8

The body's reaction to many of the chemicals in traditional cigarette smoke causes long-lasting inflammation, which in turn leads to chronic diseases like bronchitis, emphysema, and heart disease.9  Since e-cigarettes also contain many of the same toxic chemicals, there is no reason to believe that they will significantly reduce the risks for these diseases.

In fact, a preliminary study presented at the 2018 annual meeting of the American Chemical Society found that vaping could damage DNA .10 The study examined the saliva of 5 adults before and after a 15-minute vaping session. The saliva had an increase in potentially dangerous chemicals, such as formaldehyde and acrolein. Acrolein has been proven to be associated with DNA damage, for example, and DNA damage can eventually cause cancer.11

A study of mice funded by the National Institutes of Health found that e-cigarette smoke could cause mutations in DNA that could increase the risk of cancer. These specific mutations have been shown to potentially contribute to the development of lung and bladder cancer in mice exposed to electronic cigarette smoke. The researchers claim that these chemicals could also induce mutations leading to cancer in humans. It has not been reported how many of those harmed had used juul devices. While many of those harmed had vaped marijuana, many also used nicotine e-cigarettes, 12  so the risks of "juuling" need to be carefully and immediately studied.

Because they are smokeless, many incorrectly assume that e-cigarettes are safer for non-smokers and the environment than traditional cigarettes. However, a study published in the International Journal of Hygiene and Environmental Health found that the use of e-cigarettes results in increased concentrations of volatile organic compounds (VOCs) and airborne particles, both of which are potentially harmful when inhaled. 13  Although e-cigarette vapor may not result in the obvious smell and visible smoke of traditional cigarettes, it still has a negative impact on air quality, especially when vaping indoors.

There are no long-term studies to back up claims that the vapor from e-cigarettes is less harmful than conventional smoke. Cancer takes years to develop, and e-cigarettes were only very recently introduced to the United States. It is almost impossible to determine if a product increases a person's risk of cancer or not until the product has been around for at least 15-20 years. Despite positive reviews from e-cigarette users who enjoy being able to smoke them where regular cigarettes are prohibited, very little is known about their safety and long-term health effects.

There is also danger from e-cigarettes exploding in the user's mouth or face.  In 2018, the British Medical Journal used data from several agencies to estimate that there were roughly 2,035 e-cigarette explosions and burn injuries in the U.S. just in a three-year period from 2015 to 2017. One of the authors of the study stated that the number was likely higher as such incidents were not well tracked. The report also said that e-cigarettes, commonly powered by a lithium-ion battery, could overheat to the point of catching fire or exploding, a phenomenon known as "thermal runway." 14

Can Vaping Help to Cut Down or Quit Smoking Regular Cigarettes?

If a company makes a claim that its product can be used to treat a disease or addiction, like nicotine addiction, it must provide studies to the FDA showing that its product is safe and effective for that use. On the basis of those studies, the FDA approves or doesn't approve the product. So far, there are no large, high-quality studies looking at whether e-cigarettes can be used to cut down or quit smoking long-term. Most of the studies have been either very short term (6 months or less) or the participants were not randomly assigned to different methods to quit smoking, including e-cigarettes. Many of the studies are based on self-reported use of e-cigarettes. For example, a study done in four countries found that e-cigarette users were not more likely to quit than regular smokers even though 85% of them said they were using them to quit. 15 Year-long studies conducted in the U.S. had similar findings.  A study published in a prestigious medical journal in 2014 found that although smokers may believe they are vaping e-cigarettes to help them quit,  6-12 months after being first interviewed, nearly all of them are still smoking regular cigarettes. 16 Similarly, a year-long study published in 2018 compared smokers who used e-cigarettes to traditional cigarette smokers, and concluded that e-cigarette users were more likely to say they were trying to quit but no more likely to successfully kick the smoking habit, with 90% of e-cigarette users still smoking regular cigarettes at the end of the study.  Until there are results from well-conducted studies, the FDA will not approve e-cigarettes for use in quitting smoking. 17

Teenagers, Children, and Vaping

According to survey data collected between 2014 and 2017, 9% of middle and high schoolers reported that they were current vaping users. Vaping was most common among Native Hawaiian and Pacific Islanders (18%), as well as American Indian and Alaskan Native teens (13%), and least common among Black (5%) and Asian teens (4%). 18 By 2019,19 about 28% of high schoolers and 11% of middle schoolers reported e-cigarette use, with most using flavored products.20 Two 2020 surveys conducted before the pandemic closed many schools, found vaping had decreased somewhat: 1) A CDC study analyzing data from over 14,000 students, found that about 20% of 9th-12th grade students and 5% of 6th-8th grade students reported that they used e-cigarettes in the last 30 days;21 2) Researchers from the University of Michigan studied over 8,000 students in the 10th and 12th grades found that 22% reported vaping in the last 30 days.22 E-cigarette use may have dropped due to growing media coverage of young men hospitalized with serious lung damage. 21,22 The drop may also be due to raising the legal age for the purchase of tobacco products and the ban on many flavored products. 21,23

An online survey conducted in May 2020 measured how e-cigarette use changed during the pandemic, during a time where many people are staying at home.24 The survey included almost 1,500 participants under 21 (the legal age to purchase tobacco products) who reported e-cigarette use. Over half of the underage e-cigarette users who responded to the survey reported that they had changed their e-cigarette use during the pandemic. About 20% of the sample had quit using e-cigarettes altogether, about 17% reduced their use slightly or by half, and another 9% actually increased their nicotine use.

The researchers followed up by asking those participants who reduced their e-cigarette use for the reasons why they lowered it. About 14% reported that the primary reason for reducing was because they were at home and their parents would know, 18% said the primary reason was because they can no longer get the tobacco products, 23% said it was because they know e-cigarette use harms the lungs, and another 37% said that their reasons were a combination of those 3 reasons. Of those who increased their use during the pandemic, about 25% reported that it was due to boredom, 15% because they were stressed, 7% because they needed a distraction, and about 50% said that their reasons were a combination of those 3 reasons.

Future research is needed to measure whether e-cigarette use has changed even more as the pandemic has continued, as well as to measure the overall percent of youth still using e-cigarettes.

E-cigarette and juul use by young people is worrisome for several reasons:

  1. The younger people are when they begin smoking, the more likely it is they will develop the habit: nearly 9 out of 10 smokers started before they were 18.25
  2. Nicotine and other chemicals found in e-cigarettes, juuls, etc. might harm brain development in younger people.26
  3. Vaping may introduce many more young people to smoking who might otherwise never have tried it, and once they are addicted to nicotine, some may decide to get their "fix" from regular cigarettes. Whether vaping or juuling is a "gateway" to regular cigarettes or not, young people who use them risk becoming addicted to nicotine and exposing their lungs to harmful chemicals.
  4. While smoking can cause permanent lung damage over the years, vaping can cause inflammation resulting in hospitalization and permanent damage after just a few weeks or months.27,28

The sharp rise in vaping among youth highlights the need to stop manufacturers from targeting teenagers with candy-like flavors and advertising campaigns. Although the FDA banned flavors for reusable vape devices, flavored disposable e-cigarettes are still being sold.19 However, in July 2020, FDA issued warnings to 10 companies selling flavored disposable e-cigarettes, notifying them to remove their products from the market because they do not have the authorizations required to sell them .29

Even children who are too young to smoke have been harmed by e-cigarettes and related products. The liquid is highly concentrated, so absorbing it through the skin or swallowing it is far more likely to require an emergency room visit than eating or swallowing regular cigarettes. In 2012, less than 50 kids under the age of six were reported to poison control hotlines per month because of e-cigarettes. In 2015, that number had skyrocketed to about 200 children a month, almost half of which were under the age of two!30

Many e-cigarettes look like USB devices, and some are made to look like other products, in order to disguise their use. The Director of Communications at the FDA's Center for Tobacco Products has written this guide to help parents identify these hidden e-cigarettes. The FDA has also helped create this pamphlet for parents and teens to discuss the risks of vaping, and it provides resources for saying "no" and for quitting.

For more information about juuls, check out our article here.

If They Aren't Safe, Why Can They Be Sold in the U.S.?

The FDA was given the power to regulate the manufacturing, labeling, distribution and marketing of all tobacco products in 2009 when President Obama signed into law the Family Smoking Prevention and Tobacco Control Act and in 2010 a court ruled that the FDA could regulate e-cigarettes as tobacco products.31

E-Cigarette Ad

However, it wasn't until 2016 that the FDA finalized a rule to ban the sale of e-cigarettes to anyone under the age of 18 and to require all e-cigarettes that hit shelves after February 15, 2007 to go through a "premarket review," the process that the FDA uses to determine whether a medical product is safe.25 Companies were to be given from 18-24 months to prepare their applications. However, in 2017, the Trump administration appointed a new FDA Commissioner, Dr. Scott Gottlieb, who defended the safety of e-cigarettes and delayed implementing the rules until 2022.10 As the epidemic of e-cigarette use among youth became obvious, in 2018 Commissioner Gottlieb threatened to crack down on the advertising of e-cigarettes to children under 18,32 although online sales and ads are difficult to restrict. Commissioner Gottlieb resigned in 2019, and in 2019, a federal court ruled that the FDA must implement regulations in May 2020 instead of waiting until 2022.

In September 2019, amid growing evidence of teens hospitalized from vaping, President Trump proposed a ban on all flavored e-cigarettes.  No action was taken until January 2020, when Trump weakened his proposal so that it did not include a ban on menthol or tobacco flavored e-cigarettes or on large tank-style e-cigarettes.

The Biden Administration took action starting in January 2021, and for the first 8 months the FDA issued 169 warning letters to firms who manufacture and sell unauthorized e-cigarettes and vaping products with nicotine, advising them that it is illegal to sell their products because the companies did not submit an application to do so by the Sept. 9, 2020 deadline. Also in August 2021, FDA warned two companies that submitted applications by September 9, 2020 that did not meet FDA standards, and one company that submitted an application for some but not all of their products, to stop selling the products that were not authorized to be sold.

A federal court order required vape and e-cigarette companies to submit marketing applications to the FDA by September 2020, and their products were allowed to stay on the market for up to 1 year while the FDA reviewed their applications.33 During that year, the FDA rejected the applications for more than 1 million flavored vape products.34 In October 2021, the FDA authorized the marketing of three vaping products (Vuse Solo products), but rejected some flavored products from that same brand (although the FDA has not disclosed which flavors are banned and has yet to make a decision on their menthol products). As of December 2021, the FDA has yet to make a decision about many of the top vape brands, such as Juul.33

The Bottom Line

E-cigarettes, juuls, and other similar products have not been around long enough to conclusively determine the harm they cause in the long run. Unfortunately, many people, including teenagers, are under the impression that e-cigarettes are safe or that they are effective in helping people quit smoking regular cigarettes. Studies by the FDA show that e-cigarettes contain some of the same toxic chemicals as regular cigarettes, even though they don't have tobacco. There is evidence that some of these toxic chemicals can cause DNA damage that can cause cancer. More important, the reports of teens and adults who died or were hospitalized due to vaping are proof that vaping can be extremely dangerous even after just a few weeks, months, or years.

The big three tobacco companies—Lorillard, Reynolds American, and Altria Group—all have their own e-cigarette brands, so it's not surprising that e-cigarettes are being marketed and advertised much the way regular cigarettes used to be. Here are the 7 Ways E-Cigarette Companies Are Copying Big Tobacco's Playbook.

Although there are clearly serious dangers from vaping, more research is needed to confirm the impact of vaping on DNA damage, especially in children. Meanwhile, claims that e-cigarettes are an effective strategy to quit smoking are not supported by the evidence. More toxicological studies and epidemiological studies are needed to understand the hundreds of reports of permanent lung damage and deaths from vaping, and to find out whether some types of vaping are more dangerous than others in the short-term and the long-term. To understand the risks for everyone who vapes, research is needed to compare the risks of specific brands of e-cigarettes with tobacco products, as well as to neither smoking nor vaping.

All articles are reviewed and approved by Dr. Diana Zuckerman and other senior staff.

The National Center for Health Research is a nonprofit, nonpartisan research, education and advocacy organization that analyzes and explains the latest medical research and speaks out on policies and programs. We do not accept funding from pharmaceutical companies or medical device manufacturers. Find out how you can support us here.

    1. Robert Langreth. More Evidence Links Vaping Lung Injuries to Vitamin E Acetate. December 20, 2019.
      https://www.bloomberg.com/news/articles/2019-12-20/more-evidence-links-vaping-lung-injuries-to-vitamin-e-acetate
    2. Centers for Disease Control and Prevention. Outbreak of Lung Injury Associated with the Use of E-Cigarette, or Vaping, Products. Updated 2020. https://www.cdc.gov/tobacco/basic_information/e-cigarettes/severe-lung-disease.html
    3. O'Connor RJ. Non-cigarette tobacco products: What have we learned and where are we headed? Tobacco Control. 2012;21(2): 181–190. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3716250/
    4. Boyles S. Vaping Alone May Boost Lung Troubles. MedPageToday. https://www.medpagetoday.com/meetingcoverage/ats/92663 . May 18, 2021.
    5. Gaiha SM, Cheng J, Halpern-Felsher B. Association between youth smoking, electronic cigarette use, and COVID-19. Journal of Adolescent Health. 2020;67(4):519-523. doi:10.1016/j.jadohealth.2020.07.002
    6. Food and Drug Administration. Summary of Results: Laboratory analysis of electronic cigarettes conducted By FDA. FDA News & Events. July 22 2009.
    7. Varlet V,  Farsalinos K, Augsburger M, et al. Toxicity of refill liquids for electronic cigarettes. International Journal for Environmental Research and Public Health. 2015;12:4796-4815. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4454939/
    8. Pankow JF, Kim K, McWhirter KJ, et al. Benzene formation in electronic cigarettes. PLOS ONE. 2017;12(3),e0173055. https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/28273096/
    9. Centers for Disease Control and Prevention. Overviews of Diseases/Conditions. February 2019. https://www.cdc.gov/tobacco/campaign/tips/diseases/index.html
    10. McGinley, L. FDA sued for delaying e-cigarette, cigar regulations. Washington Post. March 27 2018. https://www.washingtonpost.com/news/to-your-health/wp/2018/03/27/fda-sued-for-delaying-e-cigarette-cigar-regulations/?utm_term=.f92695720619 .
    11. Lee HW, Park SH, Weng MW, et al. E-cigarette smoke damages DNA and reduces repair activity in mouse lung, heart, and bladder as well as in human lung and bladder cells. Proceedings of the National Academy of Sciences of the United States of America. 2018;115(7), E1569. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5816191/
    12. Kaisar MA, Prasad S, Liles T, et al. A decade of e-cigarettes: Limited research & unresolved safety concerns. Toxicology. 2016;365: 67–75. http://doi.org/10.1016/j.tox.2016.07.020
    13. Robert Langreth. More Evidence Links Vaping Lung Injuries to Vitamin E Acetate. December 20, 2019.
      https://www.bloomberg.com/news/articles/2019-12-20/more-evidence-links-vaping-lung-injuries-to-vitamin-e-acetate
    14. Kaplan S. E-Cigarette exploded in a teenager's mouth, damaging his jaw.  The New York Times. June 19 2019. https://www.nytimes.com/2019/06/19/health/ecigarettes-explosion.html
    15. Adkison SE, O'Connor RJ, Bansal-Travers M, et al. Electronic nicotine delivery systems: International tobacco control four-country survey. American Journal of Preventive Medicine. 2013;44(3):207-215. https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/23415116/
    16. Grana RA, Popova L, Ling PM. A longitudinal analysis of electronic cigarette use and smoking cessation. JAMA Internal Medicine. 2014;174(5):812–813. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4122246/
    17. Food and Drug Administration. Electronic Cigarettes. FDA News & Events. 25 July 2013.
    18. Odani S, Armour BS, Agaku IT. Racial/ethnic disparities in tobacco product use among middle and high school students—United States, 2014–2017. Morbidity and Mortality Weekly Report. 2018 Aug 31;67(34):952.
    19. Cullen KA, Gentzke AS, Sawdey MD, Chang JT, Anic GM, Wang TW, Creamer MR, Jamal A, Ambrose BK, King BA. E-cigarette use among youth in the United States, 2019. JAMA . 2019 Dec 3;322(21):2095-103.
    20. Gentzke AS, Wang TW, Jamal A, et al. Tobacco Product Use Among Middle and High School Students — United States, 2020. MMWR Morb Mortal Wkly Rep 2020;69:1881–1888. DOI: http://dx.doi.org/10.15585/mmwr.mm6950a1external icon.
    21. Miech R, Leventhal A, Johnston L, O'Malley PM, Patrick ME, Barrington-Trimis J. Trends in Use and Perceptions of Nicotine Vaping Among US Youth From 2017 to 2020. JAMA Pediatrics. Published online December 15, 2020. doi:10.1001/jamapediatrics.2020.5667
    22. Grady D. A Young Man Nearly Lost His Life to Vaping. The New York Times. October 15, 2019. https://www.nytimes.com/2019/10/15/health/vaping-thc-illness.html
    23. Stobbe S, Perrone M. Big drop reported in vaping by US teenagers. Associated Press . September 9, 2020. https://apnews.com/c5524d4c1e7f9148c3293cc3677c0fe5
    24. Gaiha SM, Lempert LK, Halpern-Felsher B. Underage Youth and Young Adult e-Cigarette Use and Access Before and During the Coronavirus Disease 2019 Pandemic. JAMA Network Open. 2020 Dec 1;3(12):e2027572-.
    25. Centers for Disease Control and Prevention. Fact sheets: Youth and tobacco use. Updated 2019. http://www.cdc.gov/tobacco/data_statistics/fact_sheets/youth_data/tobacco_use/
    26. Centers for Disease Control and Prevention. Preventing tobacco use among youth and young adults. 2012. http://www.cdc.gov/tobacco/data_statistics/sgr/2012/index.htm
    27. Scutti S. Teen develops 'wet lung' after vaping for just 3 weeks. CNN . May 18, 2018. https://www.cnn.com/2018/05/17/health/case-study-teen-vaping-wet-lung/index.html
    28. Song MA, Reisinger SA, Freudenheim JL, Brasky TM, Mathé EA, McElroy JP, Nickerson QA, Weng DY, Wewers MD, Shields PG. Effects of electronic cigarette constituents on the human lung: A pilot clinical trial. Cancer Prevention Research . 2020 Feb 1;13(2):145-52.
    29. U.S. Food and Drug Administration. FDA Notifies Companies, Including Puff Bar, to Remove Flavored Disposable E-Cigarettes and Youth-Appealing E-Liquids from Market for Not Having Required Authorization. Updated July 2020. https://www.fda.gov/news-events/press-announcements/fda-notifies-companies-including-puff-bar-remove-flavored-disposable-e-cigarettes-and-youth
    30. Kamboj A, Spiller HA, Casavant MJ, et al. Pediatric exposure to e-cigarettes, nicotine, and tobacco products in the United States. Pediatrics. 2016;137(6). pii: e20160041. https://pediatrics.aappublications.org/content/137/6/e20160041.long
    31. Food and Drug Administration. Regulation of E-Cigarettes and Other Tobacco Products. FDA News & Events. April 25, 2011.
    32. Saltzman J, Freyer F. The FDA issues a warning: Teen vaping is 'an epidemic.' Boston Globe. September 13 2018. https://www.bostonglobe.com/metro/2018/09/12/fda-cracks-down-vaping-orders-makers-address-sales-minors/JaiqQYzZAl4CINLufnkKlL/story.html
    33. Food and Drug Administration. FDA Permits Marketing of E-Cigarette Products, Marking First Authorization of Its Kind by the Agency. October 12, 2021. https://www.fda.gov/news-events/press-announcements/fda-permits-marketing-e-cigarette-products-marking-first-authorization-its-kind-agency
    34. Campaign for Tobacco-Free Kids. New Report: E-Cigarettes in Kid-Friendly Flavors Remain Widely Available Three Months After Deadline for FDA Action. Press Release. December 17, 2021. https://www.tobaccofreekids.org/press-releases/2021_12_17_flavor-report?