Maryland's Tobacco Resource Center - Linking Professionals to Best Practices


What Are ENDS?

ENDS, or Electronic Nicotine Delivery Systems, encompass a wide range of noncombustible tobacco products. They may vary widely in design and appearance and go by a variety of names such as: “e-cigarettes,” “e-cigs,” “cigalikes,” “e-hookahs,” “mods,” “vape pens,” “vapes,” “tanks,” and “tank systems.” Despite the differing nomenclature, they generally operate in a comparable manner and are composed of similar components1.

ENDS can be made to look like combustible cigarettes or other objects, including screwdrivers, lipstick, USBs, and pens2. Utilizing battery-powered atomizers, these devices deliver nicotine and other chemicals in vapor form to the user2, 3.  Unlike combustible tobacco products where the tobacco is burned, ENDS contain cartridges filled with aerosolizing liquid, sometimes referred to as e-liquids, e-fluid, or e-juice. These liquids typically contain a humectant, like propylene glycol or vegetable which are the base of the liquid, nicotine, flavorings, and other additives1 that are heated into an aerosol and then inhaled2.


Some manufacturers state that the fluids and flavors for their ENDS products are approved as “food grade” or “generally recognized as safe”2. However, these labels can be misleading because they refer to safety for ingestion, not inhalation2. Exhaled ENDS vapor has been tested to show that it contains chemicals that are known to cause cancer, cause harm in utero, and create indoor air pollution4. The U.S. Food and Drug Administration (FDA) expanded regulations to cover all tobacco products, including ENDS, in 20164. This law places regulations on the manufacture, import, packaging, labeling, advertising, etc. of all tobacco products4.

Based on the current understanding of the latest research, tobacco products that are noncombustible, including e-cigarettes, are likely less dangerous on most health measures than continued smoking with combustible, conventional cigarettes. However, this does not mean that e-cigarettes are harmless.  A recent review of the literature has found that e-cigarettes containing nicotine have probable negative effects on cardiovascular5 and reproductive health6. The e-liquids used in ENDS can contain a variety of flavorings that have been shown to have negative effects on dental7 and cardiovascular health8 as well.

Some individuals have reported using ENDS as a tool for helping them quit smoking or prevent relapse from smoking5. Although some people report success using ENDS to quit using traditional cigarettes, the FDA has not approved ENDS as smoking cessation devices2.



  1. U.S. Department of Health and Human Services. E-Cigarette Use Among Youth and Young Adults: A Report of the Surgeon General-Executive Summary. 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, 2016.
  2. Amiri, A., & Vazquez, K. (2017). Electronic Nicotine Delivery Systems: Are You Prepared to Have a Conversation With Your Patients?. Alabama Nurse, 44(1), 14-16.
  3. Chaudhry, I. W., Leigh, N. J., Smith, D. M., O'Connor, R. J., & Goniewicz, M. L. (2017). Labeling Information on Electronic Nicotine Delivery Systems. Tobacco Regulatory Science, 3(1), 3-9. doi:10.18001/TRS.3.1.1
  4. American Academy of Pediatrics. (2017). Electronic nicotine delivery systems (ENDS). Retrieved from
  5. Benowitz, N. L., & Fraiman, J. B. (2017). Cardiovascular effects of electronic cigarettes. Nature Reviews Cardiology, 14(8), 447-456. doi:10.1038/nrcardio.2017.36
  6. Stratton, K., Kwan, L. Y., and Eaton, D. L. (2018). Summary. In Public Health Consequences of E-Cigarettes. Retrieved from
  7. Kim SA, Smith S, Beauchamp C, Song Y, Chiang M, Giuseppetti A, et al. (2018) Cariogenic potential of sweet flavors in electronic-cigarette liquids. PLoS ONE 13(9): e0203717. https://doi. org/10.1371/journal.pone.0203717
  8. United States Department of Labor, Occupational Safety and Health Administration. (n.d.). Flavorings-Related Lung Disease, Diacetyl and 2, 3-Pentandione. Retrieved from