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E-cigarettes are safer than cigarettes and don’t cause cancer

What you may have heard

Smoking e-cigarettes or vaping can increase your risk of lung cancer.

What science tells us

These products are known by many names including e-cigs, vape pens, vaporizers, and electronic nicotine delivery systems (ENDS). They consist of a battery that turns the device on, a cartridge containing liquid (or “pod”), and a heating element that heats the contents of the pod. E-cigarettes are still fairly new and more research is needed over a longer time to determine what the long-term effects on cancer may be (ACS). E-cigarettes have become very popular and their possible link to cancer have often made headlines. While e-cigarettes do not contain tobacco, most contain nicotine, which can come from tobacco; as a result, the FDA characterizes them as tobacco products.

The FDA does not require testing of all substances in e-cigarettes to ensure that they are safe. In addition, most products do not list all of the harmful or potentially harmful substances contained in them. The US Centers for Disease Control and Prevention (CDC) has stated that e-cigarette products may contain harmful or illegal substances from unknown origins.

Epidemiological Evidence

Scientists are unsure whether or not e-cigarettes cause cancer, although they are known to contain cancer-causing chemicals. The aerosol “vapor” of an e-cigarette is not water vapor but contains a range of substances that may include:

  • Volatile organic compounds (VOCs), which can cause eye, nose, and throat irritation; headaches; nausea; and damage to the liver, kidney, and nervous system
  • Glycerin, which is linked to loss of lung function when inhaled
  • Flavoring chemicals, such as diacetyl, which has been linked to bronchiolitis obliterans, a serious lung disease

Formaldehyde, a known carcinogen that is produced if the e-liquid overheats or not enough liquid is reaching the heating element (ACS)

Toxicology Evidence

E-cigarette vapor is linked to lung cancer in many animal studies (NIH). Several animal studies have concluded that daily exposure to e-cigarettes increased cell tumor growth (Marczylo)

IARC Carcinogen Classification: Not classified (although some components of e-cigarette vapor are carcinogens, including formaldehyde, a Group 1 carcinogen, known to be carcinogenic to humans)

How to reduce your risk

E-cigarette use exposes people to potentially serious health risks. It’s important to stop using all tobacco products, including e-cigarettes, as soon as possible to avoid becoming (or staying) addicted to nicotine (JHU) . If you are having trouble quitting e-cigarettes on your own, get help from your doctor or from other support services such as your state Quitline (1-800-QUIT-NOW) or the American Cancer Society (1-800-ACS-2345).

Bottom line

There is not enough evidence yet to say that e-cigarettes cause cancer. However, e-cigarettes do not consist of water vapor alone, but contain a range of substances, including cancer-causing chemicals. E-cigarettes should be avoided because their use may lead to nicotine addiction and many other serious health conditions.

American Cancer Society (ACS): E-cigarettes
Food and Drug Administration (FDA): Vapes/e-cigarettes
Johns Hopkins: E-cigarettes
National Institutes of Health (NIH): E-cigarettes


Published: June 25, 2021
Verified/updated: August 22, 2022