E-Cigarettes and Vaping

What are e-cigarettes?

E-cigarette is a common term for “electronic nicotine delivery systems (ENDS).” Other terms used include vape pens, dab pens or rigs, tanks, mods, pod-mods, e-cigs, electronic vapor products (EVPs), e-cigars, e-hookah, etc.

The act of using these devices also has several descriptors including vaping, Juuling, dabbing, etc.^4,55

Sizes and shapes of e-cigarettes vary (e.g., shaped like cigarettes, pens, flashlights, flash drives, etc).^8,55

E-cigarette devices heat a liquid to produce an aerosolized vapor which is inhaled.⁵⁵

The liquids used may be called e-juice, e-liquid, etc.^9,55 Other substances used include wax, salts, and herbs.⁵⁵

Some e-cigarettes can be “opened” and refilled. Others are “closed,” using disposable cartridges, pods, mod pods, etc.

Do e-cigarettes contain nicotine?

Most e-cigarettes contain nicotine; however, there are some nicotine-free e-liquids.

Nicotine concentrations vary from very low to more than is found in tobacco cigarettes.^6,10,11,54

Many products use “free-base” nicotine. These higher nicotine concentrations may cause an “aversive user experience.”⁹

Devices that contain nicotine salts instead of free-base nicotine have a lower pH, allowing for high levels of nicotine to be inhaled with less throat irritation and may be “more satisfying” to the user (e.g., Juul, Suorin).^3,9,55

• Each Juul pod contains the equivalent of about 20 tobacco cigarettes.⁹ Juul is reported to have the highest nicotine content available in the US (two to ten times the nicotine concentration of most other e-cigarettes).^3,9

How are e-cigarettes used?

E-cigarettes are marketed to be used for smoking cessation. In addition, they are also being used for recreation in persons who have never used tobacco cigarettes, particularly in youth.

E-cigarettes are also used in alternate ways (with and without nicotine); such as for smoke tricks (including competitions), inhalation of flavors, inhalation of other substances (e.g., marijuana), etc. There is lots of information online and within social media on ways to use and manipulate these devices.¹²

“Dripping” is an alternate use that may increase the danger of e-cigarettes. The e-liquid is dripped directly onto the device’s heating coil. The vapor is inhaled quickly. Exposing the liquid to this higher temperature may increase the release of toxins (e.g., formaldehyde, acetaldehyde, acetone, etc) in the vapors. “Dripping” may give users thicker clouds of vapor, improved flavor, and a stronger “hit” (which appears related to a certain [higher] level of nicotine). Higher temperatures may also increase the nicotine in the vapor, leading to higher nicotine serum levels.^12,55

“Dabbing” uses higher temperatures and allows the user to inhale high concentrations (e.g., THC, CBD, nicotine) or describes the use of THC and wax in a dab pen or vaporizer.^43,55

What are the risks of nicotine in e-cigarettes?

Nicotine is highly addictive and use of e-cigarettes can cause addiction to nicotine.^3,48

The adolescent brain is more susceptible to nicotine addiction than fully developed brains of adults.^13,56

Nicotine alters brain development.⁵⁶ It can affect cognitive function, memory, and attention when used while the brain is still developing into the mid-20s.^3,5,60

Nicotine is absorbed in e-cigarette users. Approximate saliva concentration of a nicotine metabolite (cotinine):¹⁷

• e-cigarettes (average use 220 puffs/day; variable nicotine content): 353 ng/mL
• tobacco cigarettes (26 per day): 340 ng/mL
• nicotine patch 21 mg: 165 ng/mL
• nicotine nasal spray, 24 doses per day: 150 ng/mL to 200 ng/mL

E-cigarettes are a source of secondhand exposure to nicotine and other chemicals. The risks of secondhand vapor are unknown but are expected to be lower than tobacco smoke. Caution is recommended around nonusers, youth, pregnant women, people with cardiovascular conditions, etc.^18,57

What are the risks of the chemicals found in e-cigarettes?

Analysis of common brands of e-cigarettes showed contents included propylene glycol, glycerol, glycerin, flavorings (e.g., diacetyl), diethylene glycol, ethylene glycol, ethanol, formaldehyde, and acrolein. The effect of chronic exposure to these chemicals is not known.^6,19,20,47

• Some of these ingredients are generally regarded as safe (e.g., propylene glycol, vegetable glycerin) when used orally; however, their long-term safety when inhaled is unknown.^47,48,58 When propylene glycol and glycerin are heated, toxic aldehydes are formed. Inhaling these toxins has unknown effects.⁴⁷
• Acrolein (primarily used as an herbicide) can cause acute lung injury, COPD, and may cause asthma and lung cancer.⁷
• Some data suggest that flavorings may increase the risk of cardiovascular disease.⁶²
• Bronchiolitis obliterans (also called “popcorn lung”) is associated with the inhalation of flavorings (e.g., diacetyl); found in microwave popcorn, other food products, and e-cigarette products.⁴⁸

The release of chemicals and contaminants (e.g., nickel, tin, aluminum, lead) in e-cigarette vapor varies between devices and the way they are used. More chemicals are released (e.g., formaldehyde [a known carcinogen], etc) at higher temperatures (e.g., with “dabbing” or “dripping” [described in the “How e-cigarettes are used” section above]).^{6,12,14,20,48}

What are the respiratory risks from e-cigarette use?

There are case reports of e-cigarette use being linked to:

• mild respiratory symptoms (cough, wheezing, etc).^22,53
• acute lipoid pneumonia associated with the inhalation of oil via e-cigarette devices.⁴⁹
  • In most cases, cannabis oils seem to have been used in the e-cigarette devices.⁴⁹
  • Most commercially available e-cigarette liquids do not appear to contain oils.⁴⁹
  • Patients should not inhale any oil-based liquids in e-cigarette devices.⁴⁹
• hypersensitivity pneumonitis.²³
• suspected bronchiolitis obliterans (also known as “popcorn lung”).⁵⁹

What are the risks of severe lung disease from e-cigarette use?

More than 2,800 cases of severe lung disease associated with the used of e-cigarette products has been reported in the US. CDC is investigating these cases and have confirmed at least sixty-eight deaths as of February 18, 2020.⁴⁴

• Symptoms include cough, shortness of breath, chest pain, nausea, vomiting, diarrhea, fatigue, fever, and weight loss.⁵²
• There is a strong link between tetrahydrocannabinol (THC)-containing products, especially those that contain vitamin E acetate, and cases of e-cigarette- or vaping-associated lung injury.^44,46
• In response to the reports of acute pulmonary illnesses linked to the use of vaping products in the US, Health Canada has issued an information update regarding the risks of vaping products. They recommend anyone using vaping products should monitor themselves for symptoms of pulmonary illness (e.g., cough, shortness of breath, chest pain).⁴⁵
• Any suspected cases of lung disease associated with e-cigarettes/vaping should be reported to local or state health departments, following the recommendations in CDC’s Health Advisory statement, found at https://emergency.cdc.gov/han/han00421.asp.

The Canadian Lung Association warns that urgent action must be taken to decrease vaping in youth and that inhaling e-cigarette vapor causes cough, wheezing, worsening of asthma symptoms, and unknown long-term effects.²¹

The American Lung Association has called for CDC and FDA to state that e-cigarettes are not safe, that they contain dangerous chemicals that can cause severe and irreversible lung damage and disease, and that the public should stop using e-cigarettes and vaping.⁵¹

What are the cardiac-associated risks from e-cigarette use?

There are no long-term data on the risks of nicotine delivered via e-cigarettes (e.g., heart, lungs, etc).¹⁵

• There are limited data about cardiac effects suggesting the possibility of increased heart rate, blood pressure, and arterial stiffness.¹⁶

Further investigation is needed to fully understand the cardiac effects of e-cigarettes¹⁶

What other risks may be associated with e-cigarette use?

Seizures and other neurological symptoms (e.g., tremors) have been reported in patients using e-cigarettes. FDA is investigating these reports and their association with e-cigarettes.⁵⁰

Are youth who use e-cigarettes at risk of becoming smokers?

Preliminary evidence suggests that youth who use e-cigarettes are more likely to smoke tobacco cigarettes and use cannabis at a later age than youth who don’t use e-cigarettes.^24,25,47,60

Are e-cigarettes effective for smoking cessation?

E-cigarettes are not an approved smoking cessation aid.^64,65

Some smokers claim that e-cigarettes make them “feel better” than when smoking tobacco cigarettes, that they save money, and that e-cigarettes help them to quit smoking.²⁶

Some evidence suggests that among people who are dual users (users of tobacco cigarettes and e-cigarettes), daily e-cigarette use may be associated with an increased chance of becoming smoke free.⁶⁶

Some evidence supports the use of e-cigarettes to help patients quit smoking.^{2,27,28,42,57}

Royal College of Physicians (UK) supports the use of e-cigarettes, in combination with behavioral therapy, in smokers who have tried other methods of quitting without success.^29,30

Patients who want to quit smoking should be advised to use proven smoking cessation methods.

• For practical tips and resources to help your patients successfully quit smoking see our toolbox, Smoking Cessation: Helping Patients Who Use Tobacco.
• If patients have failed multiple attempts with approved nicotine replacement/smoking cessation products they could try e-cigarettes.^15,31

Can e-cigarettes be used in public places?

Rules vary, but many public places (airplanes, hotels, etc) consider e-cigarettes and vaping within their no-smoking policies.³²

Some e-cigarettes may trigger certain types of smoke alarms.³³

Rarely, e-cigarettes have been associated with explosions (lithium battery), fires causing serious burns, and death.^2,34

Can e-cigarettes be used by hospitalized patients?

Many hospitals include e-cigarette use by patients and visitors in their no smoking policies.³⁵

Patients who use e-cigarettes may experience a withdrawal syndrome from nicotine.

Hospitalized patients who cannot use e-cigarettes should be offered nicotine replacement therapy if needed. The amount of nicotine in e-cigarettes can vary. Some hospital nicotine replacement protocols recommend starting e-cigarette patients on low-dose nicotine replacement therapy, then monitoring and titrating as needed.

Are there poisonings with e-cigarettes?

The flavorings of e-liquids and designs of the devices are very appealing to children. They must be kept in a safe place, out of reach of children and pets.⁶

Poison control center cases related to e-cigarettes and liquid nicotine range from 1,540 to 5,356 cases/year between 2013 and October 31, 2021.³⁶

Commercially available e-liquids can contain up to 100 mg/mL of nicotine. Just 1 mg of nicotine can cause adverse symptoms in a toddler, and 6 mg/kg to 13 mg/kg can be lethal.^37,38

Poisonings from e-liquids are reported from ingestion, skin contact, or by inhalation.^39,60

Symptoms of nicotine toxicity can include nausea, vomiting, diarrhea, salivation, weakness, hypertension, and tachycardia. In severe cases seizures, coma, and death can occur.⁴⁰

Use caution when handling e-liquids to avoid skin exposure, due to the potential for topical nicotine absorption.

How are e-cigarettes regulated?

Regulations for e-cigarettes and vaping are evolving.

FDA and Health Canada regulate all aspects of e-cigarettes and vaping products including packaging, promotion, banning of ingredients or devices, etc.^1,6

Vaping products with nicotine are available to adults as an alternative to smoking.⁶

E-cigarettes are not able to be purchased by those younger than 21 years of age (18 years of age in Canada).^6,41

Healthcare professionals are also calling for regulations on these devices that may prevent them from being manipulated for alternative uses (e.g., dripping, etc).¹²

What does the FDA’s authorization of the Vuse Solo e-cigarette mean?

Currently, the only e-cigarettes authorized for marketing by the FDA are Vuse Solo device and its tobacco-flavored pods.⁶¹ Note the menthol-flavored Vuse Solo pods are NOT currently authorized for marketing by the FDA.³

Help patients understand what this authorization does and doesn’t mean.

• To receive authorization to market a new tobacco product, a manufacturer must demonstrate the product would be “appropriate for the protection of the public health.”⁶¹ The Vuse approval was based on short-term data (see below) and the determination that the possible benefits would outweigh the risks to the public (e.g., abuse by youth).⁶¹
• FDA “authorization” does NOT mean that Vuse Solo e-cigarettes are safe or effective for smoking cessation.
• There are not long-term data that Vuse Solo helps patients reduce or stop smoking.
• Though laboratory data may suggest that e-cigarettes are less toxic than traditional cigarettes, outcomes data in humans confirming this are lacking.
• Based on short-term data (weeks), adult smokers who use Vuse Solo instead of smoking traditional cigarettes may have reduced blood and urinary biomarkers of exposure to carcinogens and other toxins (e.g., volatile organic compounds [VOCs], tobacco-specific nitrosamines [TSNAs], and polycyclic aromatic hydrocarbons [PAHs]) compared to continued use of traditional cigarettes.⁶³
• There are not long-term data assessing the effects of long-term use of Vuse Solo (exclusive use or dual use with traditional cigarettes). Dual use is common. For example, in some states data suggest that up to ~40% of adults who use e-cigarettes are dual users.⁶⁷

What information is available to help educate patients about the risks of e-cigarettes?

CDC and Health Canada offer information sheets to help parents talk with their teenagers about e-cigarettes (https://e-cigarettes.surgeongeneral.gov/documents/SGR_ECig_ParentTipSheet_508.pdf and https://www.canada.ca/en/services/health/publications/healthy-living/talking-teen-vaping-tip-sheet-parents.html).

FDA has expanded its Youth Tobacco Prevention Plan to include tools to help prevent vaping in youth with The Real Cost of Vaping (https://www.scholastic.com/youthvapingrisks/index.html).

Safer ≠ Safe (https://www.thetruth.com/article/safer-safe) is another campaign to educate about the risks of e-cigarettes.

There are little data on effective strategies to quit e-cigarettes. Patients can consider traditional smoking cessation strategies, but keep in mind that even data for smoking cessation in teenagers are limited. See our toolbox, Smoking Cessation: Helping Patients Who Use Tobacco, for practical tips and resources.