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vaping & electronic cigarettes

what is vaping casaa

What is vaping?

Electronic cigarettes (also known as e-cigarettes, vapes, or vapor products) are an alternative to tobacco cigarettes.

Nearly all vaping devices operate on a fairly simple principle: A liquid substance (commonly called e-liquid) is converted to an aerosol through the process of heating – like water turning to steam.

When someone uses an e-cigarette, the device’s battery sends an electric current to a wire coil wrapped around liquid-soaked wicking material, causing it to heat up. Once the coil becomes hot enough, it heats the surrounding liquid into an aerosol. The aerosol, or vapor, is then inhaled by the user.

Because people who vape inhale an aerosol, and not smoke, they often refer to themselves as “vapers” to distinguish themselves from people who smoke.

View our Electronic Cigarettes Frequently Asked Questions for more information.

What is vaping used for, and who does it?

Smoking Cessation

The first commercially successful electronic cigarette was invented in 2003 by a Chinese pharmacist named Hon Lik. Hon’s father, who smoked heavily for many years, had recently died, and Hon wanted to develop a device that could help him stop smoking, in an effort to avoid his father’s fate.

By 2007 vapor products had found their way to Europe and the United States, and in the years that followed enthusiasts who successfully used them to stop smoking continued to refine and improve the technology, giving us the wide array of vapor products we have today.

Public health and government officials often claim “there is no evidence that e-cigarettes help people quit smoking.” But according to recent studies there is evidence showing that vaping is effective in helping people give up cigarettes. Moreover, recent industry data shows that more than three million people in the United States have switched from smoking to vaping.

Thousands of people report quitting smoking because of e-cigarettes in the testimonials section of this website. According to survey data, hundreds of thousands more are estimated to have done the same.

It is mind boggling to claim that hundreds of thousands of people are somehow confused or wrong about how e-cigarettes helped them become ex-smokers.

The people who are not convinced that e-cigarettes help people quit smoking are simply not thinking like good scientists and have a highly biased conceptualization about what smoking is and how people quit. They tend to think of smoking as a medical problem akin to a disease for which a cure should be sought. This limits the type of research they find acceptable in determining if vaping has value in helping people quit smoking.

About Vapers

A number of surveys have been conducted in the United States and United Kingdom to help characterize which groups of people are vaping. The data from these surveys is consistent enough to make some general conclusions:

  • The vast majority of daily vapers are people who smoke or used to smoke. (This is unsurprising given the similarity of nicotine vapor products to tobacco cigarettes.)
  • A large number of daily vapers are people who used to smoke, but now vape exclusively.

A large portion of people who vape continue smoking cigarettes. At the time of this writing, they make up roughly half of all people who vape. These people are referred to as “dual users.” The fact that there are a sizable number of dual users is also unsurprising. Some dual users are simply vaping in places or situations where smoking is inappropriate, but continue to smoke cigarettes when they are able to. Other dual users are actively attempting to stop smoking, but continue to smoke while they experiment with vaping.

By far, the smallest group of vapers are those who have never smoked.

See more results from the 2019 EcigIntelligence Survey.

EcigIntelligence US Vapers Survey

EcigIntelligence US Vapers Survey

Youth Usage

CASAA supports laws that prohibit underaged sale (<18) and urges strict enforcement of these laws. However, CASAA does not support laws that criminalize people of any age possessing or using nicotine products.

History shows us that youth have a knack for getting ahold of and using products they are forbidden to have (e.g., cigarettes, alcohol, drugs). The same is true of vapor products. Young people are an especially curious bunch and many, especially those approaching adulthood, are naturally attracted to products and activities that are considered strictly for adults. So it is no surprise that many young people have tried vaping.

Accurate information about the number of young people vaping nicotine is often misunderstood due to the publication of cherry-picked data, media hype, and agenda-driven conclusions.

The most egregious spin is applied to the data on “current vaping.” The CDC’s National Youth Tobacco Survey (NYTS) is the source cited for the majority of vaping and tobacco usage data on young people. This survey asks middle and high schoolers if they have vaped, even once, within the last 30 days, and if the answer is “yes” they are recorded as a “current user.” Even if they never touch another vapor device in their life, they are recorded for that year as “currently vaping.” Using this data as a metric is highly misleading considering the propensity for youth experimentation, and the perception by the public that “current vaping” means they are vaping regularly or daily. Imagine having 1 or 2 alcoholic beverages in a month and being called a “current alcoholic.”

The NYTS does collect data on how frequently youth are actually using vapor products, but this additional information has been omitted from the published findings in the past, and more recently, is not emphasized when it is published. This more detailed frequency data shows us that while 19.6% of high schoolers in 2020 were recorded as “currently vaping,” only 7.6% used vapor products “frequently” (on 20 or more days out of the last 30), and even less (4.4%) use vapor products on a daily basis.

Newly available data for 2021 shows a dramatic 59% decrease in “current vaping” since 2019, putting the current usage rate back to “pre-epidemic” levels. 

The Gateway Theory

The “Gateway Theory” proposed by some researchers claims that youth who vape will be more likely to start smoking cigarettes. They come to this conclusion by looking at youth who vaped and also smoked, and creating a causal link between the two. This also is extremely misleading because correlation does not equal causation. If you were to examine the number of adults who use illicit drugs and those who also drink alcohol you’d find a dramatic correlation – many people do both. But that does not mean that drinking alcohol is a gateway to drug use.

It is not at all surprising that someone who would be interested in vaping would also be interested in smoking, given their similarity, or that teenagers would try both, being novelty-seekers in general. It does not mean that experimenting with one product causes someone to try the other.

Moreover, the steep decline of cigarette smoking in young people, coupled with the fact that the majority who vape have a history of smoking, implies that vapor products are likely an off-ramp from smoking cigarettes, not a gateway.

Additionally, a major flaw in the data presented by the NYTS is that it is unable to definitively say what young people are vaping. Vaping cannabis and THC has also become increasingly popular in recent years, and since vapor products and e-cigarettes are often conflated with cannabis vaping products, it’s possible some youth may be reporting cannabis vaping, not nicotine vaping.

casaa gateway theory graphs

What are vapor products?

Vapor products come in a wide range of options.

From small to large, there is a device and e-liquid out there to meet the needs of a diverse consumer base.

While some people prefer the convenience of plug-and-play small devices that come pre-filled with liquid, other people require customizability and prefer the enhanced performance of more advanced, open-system products.

Whether you prefer to carry your e-cigarette in a shirt pocket or you do best with a setup that requires its own handbag, there is a liquid and device combination out there for almost anyone who wants to switch from smoking to vaping.

Open System vs Closed System

Vaping devices come in all shapes and sizes and can be roughly categorized according to their simplicity, customizability, and capacity. An important distinction between devices is whether they are a closed or open system.

Closed system devices are not designed for modification by the user. The battery, coil, and cartridge/pod containing the e-liquid are self-contained. The only flexibility is being able to switch pre-filled pods/cartridges to change flavor or nicotine strength.

In contrast, all aspects of open system devices can potentially be changed to suit one’s preferences and needs – everything from the resistance and material of the coil, the type of wicking material, the style of airflow on the device, to the power of the batteries, and then some.


Lithium ion batteries are used in everything from e-cigarettes, to cell phones, to laptop computers, to the Boeing 787 Dreamliner. What the batteries in all these devices have in common is that they very rarely catch fire or explode. E-cigarettes are a relatively new product, so when their batteries catch fire or explode it makes headlines. Many times these incidents are the result of improper charging (using the wrong adapter) or storage (carrying a battery in a pocket with other metal objects). But, how common is it for e-cigarette batteries to explode?

According to The U.S. Fire Administration, between 2009 and 2014 there were a total of 25 incidents of fire and explosions involving e-cigarette batteries, leading to nine injuries and no deaths. In comparison, the Consumer Product Safety Commission has issued 40 recalls since 2002 on laptop and notebook computers due to fire and burn hazards. Lithium ion battery fires and explosions, for the most part, are of little concern for the vast majority of those who use an e-cigarette, laptop, cell phone, or take a flight on a Boeing 787. The industry that makes these batteries is working to make them safer. CASAA is working with others to develop battery safety guidelines for e-cigarette users. Meanwhile, there is no reason to think this problem is especially confined or more highly concentrated in vaping devices.


The liquids used in e-cigarettes, no matter what the device, typically include a combination of four main ingredients: propylene glycol (PG), vegetable glycerin (VG), flavorings, and (optional) nicotine. The combination and ratio of these ingredients depend on the preferences of the user.

Propylene Glycol

Propylene glycol (PG) is manufactured in large quantities because it has a wide variety of uses from food products, to drugs, to entertainment. It imparts little flavor of its own, and keeps packaged food from drying out. In many oral and topical drugs it’s used as a stabilizer. In theater productions PG is used to simulate fog. E-cigarette liquids contain PG because it mixes well with flavoring ingredients, and when heated, produces a smoke-like vapor. Because it is a slight irritant, it also mimics the sensation of inhaling cigarette smoke.

Vegetable Glycerin

With similar properties as PG, vegetable glycerin (VG), which is almost exclusively derived from plants, is widely used as a food additive and in drug manufacture. It also imparts a sweet flavor and helps keep foods moist. It is used in e-cigarette liquids for much the same reason as PG. Because VG is thicker than PG, vapers use an e-liquid with a higher VG content when they want to exhale vapor plumes that are thicker and more voluminous.


Flavorings are themselves combinations of different flavoring chemicals, and almost all flavoring ingredients used in e-liquids are the same or similar ones used in foods and drinks. There are thousands of flavors used in the food/beverage industry, and the same is true for e-liquids manufactured for use in vapor products. One medium-sized company can easily offer more than 30,000 flavor/nicotine combinations. The most common categories are: fruits, dessert/bakery, sweets/candy, custards/ yogurts, breakfast, mint/menthol, beverages, tobacco, and savory/spice.


E-cigarettes are designed as a low-risk alternative to smoking, and because almost all vapers currently smoke or are vaping to quit and enjoy the effects of nicotine, nicotine is an important ingredient for many of them. A practical advantage over tobacco cigarettes, e-cigarette devices allow users to fairly precisely control the amount of nicotine they use.

E-cigarettes are available in a range of nicotine strengths allowing people to choose the amount of nicotine delivered to meet their personal needs. People who use e-cigarettes to quit smoking often start with a higher nicotine level and may gradually reduce the nicotine as they find themselves less dependent on cigarettes. This behavior is similar to that modeled by Nicotine Replacement Therapies (NRTs) like patches, gums, and lozenges. The striking difference, however, is that people who choose vaping typically do so enthusiastically, as opposed to NRTs which often require coercion from doctors or other societal pressures.

protest photo benefits of vaping flavors CASAA
Why Flavors Matter

While many people new to vaping might initially choose flavors similar to tobacco, the vast majority eventually move on to other flavor categories in an effort to distance themselves from the experience of smoking cigarettes.

Various polls conducted over the years show a consistent preference for fruit or dessert flavors among adults who vape. One of the key issues that makes vaping a more personal experience is the availability of a wide range of different flavors.

Many people enjoy more than one flavor during their day, and the ability to experiment with new flavors keeps vapers engaged (as opposed to returning to smoking). Research supports the anecdotal evidence that adults who vaped flavored vapor products are more likely to quit smoking.

What are the risks associated with vaping?

Chemical analysis of e-cigarette vapor, and the likelihood that these chemicals are not causing harm, is a solid foundation for evaluating potential risks. But the story is incomplete without looking at the effects these devices are having on people in the real world. After all, what we are ultimately interested in is what happens to people when they use e-cigarettes.

Scientists have amassed a great deal of data from people who vape. This information comes by way of:

  • Self-reports (surveys asking about use, symptoms, and other negative or positive consequences); and,
  • medical and scientific data (reports from clinicians and scientists about what they’ve observed in people who vape)

What we’re looking for is a clear pattern of symptoms or illnesses that occur in people who vape, and is not found in non-vapers.

Millions of people around the world are vaping, some for 10+ years, without experiencing negative health effects. Of course, some people report minor issues like throat irritation or coughing, but these tend to go away with time, discontinued use, changing devices, or trying a different e-liquid. Making sure to drink plenty of water helps, too. But, as noted, these issues are typically quite minor, and many (if not most) people who switch from smoking to vaping report a gradual reversal of symptoms like coughing and shortness of breath.

What You Should Know About E-cigarettes and EVALI

Clearing up misinformation and myths

Out of the millions of people who vape worldwide, there have been few reports of anyone suffering lasting or permanent harm resulting from intended use of a properly functioning e-cigarette.

This does not include accidental poisonings or catastrophic device failure like battery explosions. These problems, while rare, are separate safety considerations. This also does not include the 2019 outbreak of lung injuries linked to illicit THC oil cartridges (and not nicotine-containing e-cigarettes). Notably, the so-called “EVALI” crisis almost exclusively affected the United States. Millions of people around the world continue to use vapor products with no similar incidents of mass injury.

We have information from millions of people vaping under normal use conditions with almost no serious problems reported. Because of this we can be confident that nicotine vaping poses few short-term health risks.

Assessing the risk of long-term use requires more information. In the interim, we are making predictions based on incomplete, but best available data. It is possible that in 20 or 30 years nicotine vaping could become identified as causing some harm, but those harms would have to be very serious and significant in order to outweigh the public health benefit associated with people reducing or eliminating their smoking habit.

Replicating real-world conditions is a problem inherent in almost all research investigating potential harm resulting from long-term vaping. Assuming these studies are well conducted and they’ve managed to create laboratory conditions that mimic how things work in the complex real world (most do not), and they’ve found something that suggests a possible cause of harm, then what they have found is a hypothesis about something that might cause harm. But in press releases of scientists that the media turns into news, it is strongly implied they have found evidence of harm. A hypothesis is not evidence, though.

What we’re seeing in the media today is a series of educated (and many not-so-educated) guesses about the long-term risks of vaping and using nicotine. But well-trained scientists know better than to accept claims in splashy headlines. They know the results from single studies can only point the way to further research (at best). Individual studies can’t be definitive in their conclusions about long-term harm either. In reality, research shows that at present, there is no credible reason to strongly suspect e-cigarettes pose significant long-term health risks. This is not the same as saying it is impossible for there to be any long-term risks, only that it appears that long-term risks are unlikely.

This puts e-cigarettes in the same position as other new products released on the market. Consider new prescription drugs, cell phones, and artificial sweeteners. It was fairly clear what these things were and how they worked. No short-term harms were identified, nor were there any convincing reasons to suspect they had a high likelihood of causing long-term harm. So they were allowed on the market with the knowledge it was possible that they may cause some harm following long-term use. We allow this because there would never be a new drug or product ever released if we had to be 100% certain there would be no long-term risks. Moreover, new products like these have a high degree of probability of improving people’s lives compared to the potential risks. In other words, the potential benefits outweigh the hypothetical harms. This is especially true of e-cigarettes, which are helping us replace a known harmful activity with something demonstrably safer.

Risks for Vapers

Making an accurate estimate of the health risks of consumer products such as food, beverages, consumer goods, and medication is a complex process. It involves reams of data from many fields of study and careful scientific analysis.Vapor products have been on the market for more than ten years, becoming very popular only in the past five. By some accounts, ten years is not enough time to identify all the potential health risks vaping may pose. But we know a lot already about what’s in e-liquid, how the devices work, and how people use them.

We can be very confident that vapor products cannot be as dangerous as cigarette smoking.

The Royal College of Physicians, in their extensive review of the evidence in 2016, says “the available data suggest that [nicotine vapor products] are unlikely to exceed 5% [of the health risk] associated with smoked tobacco products, and may well be substantially lower than this figure.” The best available estimate of vaping risk would be to compare it to another popular form of non-combustible tobacco use: smokeless tobacco. Strong epidemiological evidence puts the health risk of moist, pasteurized smokeless tobacco (also called snus) used in Sweden and the United States at approximately 1% compared to the risk of smoking.

Risks for Bystanders

Igor Burstyn of Drexel University reviewed over 9000 measurements of the chemicals in e-cigarettes. Burstyn focused on contaminants associated with a risk to health and compared the values observed to occupational workplace safety standards. To put the results in context Burstyn compared a vaper’s deliberate exposure to these contaminants to what a person might experience involuntarily in a workplace. He concluded that even after decades of exposure the risk to bystanders would not justify any attention. Indeed, the values obtained were between 1% and 5% of the levels needed to cause a health concern in a workplace. Even so, Burstyn was cautious about the common ingredients PG and VG. There is no established level of exposure for these ingredients that represents a threat to health. Before e-cigarettes, inhaling a vapor of PG or VG was such a rare event, there was no need to establish a standard. It is commonly understood that PG and VG are generally benign substances, but only recently have large numbers of people been inhaling them. In other words, we have no good reason to suspect inhaling PG or VG is harmful, but because this is a new kind of exposure, the cautious thing to do is the same thing we do with new drugs consumed by large numbers of people. We observe the users and look for signs and reports to see if any negative health effects are emerging.

We know from the Burstyn study how low the risks are for those who directly inhale e-cigarette vapor. Bystanders have far less exposure to e-cigarette vapor for three simple reasons: (1) what an e-cigarette user exhales has less volume than what they inhale because some of the vapor remains inside the body; (2) what the user exhales is immediately diluted by the ambient air; and (3) e-cigarette aerosol is liquid droplets that evaporate fairly quickly. Using Burstyn’s estimate as a guide, a bystander would have to be in a room with 100 to 1000 people vaping to inhale in one breath a similar amount of vapor an e-cigarette user inhales in a single puff. This makes exposure risks to bystanders virtually zero in any real-life situation.

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