Participants were 31% cisgender women and 69% cisgender men; 46% African American, 31% European American, and 23% other races; 46% had a bachelor’s or graduate degree; and 31%, 54%, and 15% were aged 18–24, 25–44, and 45–64 years, respectively. No participants self-identified as Hispanic or Latino. All 13 participants were daily ENDS users and only one participant (Daniel) was a past 30-day dual user of cigarettes and ENDS. All participants modified the ENDS devices they routinely used. Table 1
presents the pseudonym, demographic information, tobacco use, and ENDS modification practices of each participant. Information about vaping initiation was retrieved from the interviews.
3.1. Types of Users’ Modifications to ENDS
Overall, participants engaged in various ENDS modification practices. Modifications to coils and batteries were most commonly discussed. Users also refilled closed pods, changed e-liquids with different flavors, or even created their own e-liquids.
Of the 13 participants, all but one mentioned that building and replacing coils were the most common and intensive modifications. Building coils refers to making users’ own coils from basic materials. While the exact techniques for coil building for each type of ENDS device differs, the major steps generally involve preparing a piece of wire, wrapping the wire around a small screwdriver a specific number of times, installing and testing the coils, and wicking the coils (inserting a wick). Some participants expressed that although building coils appears to be straightforward, it is actually quite time-consuming and requires intensive self-learning. Thus, instead of building their own coils, more often users replaced existing coils with pre-built coils from manufacturers. The new coils, either built or replacement, usually have different levels of wattage range, numbers of wire wraps, wire gauge, and/or wire materials (e.g., nickel versus stainless steel) than the old ones. Anthony, a former vape shop worker, said he and other retailers always recommended customers change coils to meet their individual needs. In addition, George indicated that some users built and sold coils to other consumers full-time.
Participants mentioned several reasons for modifying their coils. First, users built and replaced different coils so that they could experience various cloud densities. Several interviewees explained that coils with different forms of wire wrapping yield different heating speeds, which lead to more or less dense clouds. Anthony also stated that some ENDS users participated in cloud competitions at which people competed for the thickness and density of their clouds.
Moreover, users sometimes preferred different levels of nicotine delivery and thus, switched between different types of coils with various wattage ranges, such as smaller coils with higher resistance for salt nicotine and bigger coils with lower resistance for regular or freebase nicotine. Similarly, altering the number of wire wraps, wire gauge, and wire materials results in different wattage ranges of coils, which affects the flavor and tastes of e-liquids. Jacob said, “Coils were so bad previously. They were fine, but the flavor wasn’t there. You had limited (control) over the cloud production, how much power you could push through the coil without burning the coil. So most of the people that got into building their own devices got into there so they can do higher wattage, lower nicotine, bigger cloud”. In addition, a couple of participants modified coils to experience stronger or weaker throat hits, or different sensory perceptions. Anthony explained, “If you want a smoother hit, you want to go something closer to a mesh coil, which has mesh fibers on the inside so it’s better airflow and it’s a smoother hit, rather than the T12 or the T10, which has higher wattage coils, which is a stronger hit, higher wattage”. Finally, Josh commented that some hobbyists built their own coils for aesthetical reasons, called “coil art”.
3.1.2. Cotton Wicks
More than half of the participants mentioned that they switched between different types of cotton wicks to identify the right choice. Three categories were discussed, including regular cotton, organic cotton, and Japanese cotton. The regular cotton refers to cotton materials purchased in regular stores that are not intended for vaping. Several participants expressed that regular cotton is often bleached and contains harmful chemicals, which makes the products unsafe and affects the tastes of e-liquids. Organic cotton is unbleached cotton designed for vaping. Charlotte pointed out a specific product named “cotton bacon” that is often in strips, offers faster e-liquid absorption, and has higher heat resistance. The last category is Japanese cotton, which is often pad-shaped, produced in Japan, and originally used for skincare purposes. Anthony believed that Japanese cotton has the finest quality and lasts longer than other cotton wicks. He also said, “If you had regular cotton where you’re buying from the store, it wasn’t organic, you would blow the cotton and that was to get the chemicals off of the cotton before you would put it in your mod”. Thus, users mainly modified their cotton wicks for safety, taste, and quality reasons.
All but one participant mentioned modifying batteries in their ENDS devices. Several practices were commonly stated, including replacing an old battery with a new battery of the same type, upgrading from internal to external batteries, switching smaller mods with bigger ones, and installing specific batteries into devices that were not designed for those types of batteries.
Batteries can become worn out and malfunction as they age. Thus, for safety concerns, many users replaced the worn batteries with new ones. Alex said, “There have been rumors that vapes are expanding and exploding because of a battery malfunction, so if your battery is nice and clean like this, then it’s safe to go… If it’s torn, no matter if it’s torn by the littlest bit, I will just get a whole new battery itself”. In addition, users sometimes upgraded their old batteries to the same type of products with better quality. Jack explained that as lower-end batteries are running low, the throat hits become weaker. Therefore, some users upgraded to higher-end batteries that last longer and keep the throat hits consistent even when the batteries are low.
Some interviewees stated that ENDS users sometimes switched an internal battery with an external battery or upgraded from a smaller mod to a larger mod. Internal batteries often have lower wattage outputs and heat coils more slowly than external batteries. Bigger mods hold a larger number of batteries and are compatible with stronger batteries. Thus, users who wanted to produce larger clouds and experience stronger throat hits would change their batteries and mods to increase the devices’ wattage outputs. Caleb, a vape shop worker, said, “A lot of people that come in here and upgrade from an internal battery to an external battery, just for the bigger cloud, the harder hit… Once you don’t get the wattage that you like, you grab the bigger mod, you have ‘Big Beast’ now, you put batteries in, you’re going to get that huge cloud that you were trying to look for”.
Another common practice of battery modification is to install a battery in a device that was not designed for that battery. Participants expressed that sometimes they preferred a lower wattage output, below the designed wattage ranges of their devices. In those cases, they needed to install lower power batteries; yet, the battery sizes usually did not fit the devices, requiring them to put in “battery adapters”. Anthony described, “Pretty much that mod specifically is made to where it takes 2700 batteries. If I wanted to put an 18650 battery in there which is less power, I would have to do a build for that to pretty much feed that. And at the same time, 18650 wouldn’t fit into this bigger mod since it was made for 2700s. They have little adapters and little smaller pieces you would be able to say, ‘Okay, I want to put my battery in a sleeve and put it in my mod’, then it would work”.
About half of the participants mentioned modifications to chipsets. Similar to those in computer systems, chipsets in ENDS devices include a set of electronic components that automate the process of charging and modifying the amount of power that the devices provide. Interviewees explained that chipsets are usually considered “higher-end” and provide an enhanced experience by allowing for automatic preheating, temperature control, and wattage control. The most commonly discussed modification was to change chipsets in order to alter the heating functions of the devices. Jacob mentioned that he replaced a chipset that offered only one wattage output with a new chipset that automatically increased wattage outputs as the device heated up. Adding manufactured chipsets to their own devices was also mentioned, but participants underlined that those modifications were often performed on devices not intended to be modified. Josh said, “I don’t think some manufacturers intend on having their devices altered, whether it’s dismantling the device and then people put in different chipsets. But there are a lot of people who actually try to build their own device. They take companies-like (manufactured) chipsets and they put it into a piece of wood, and they carve it out and build their own devices”.
More than half of the participants mentioned modifications to e-liquids. Three practices were commonly discussed, including refilling closed pods that are not meant by the manufacturer to be refilled, changing e-liquids with different flavors or nicotine levels, and producing their own by mixing different e-liquids or other substances. First, many users bought pre-made e-liquids to refill their closed pods. Reasons often mentioned were to lower the cost and increase control over the products they use. Participants also suggested that certain closed pods were easy to open, which encouraged them to refill the pods. Kayla said, “I can just use my fingertips and open up the device very easily. It’s very easy to do. And with JUUL, I usually use a tool to open this bottom part and add the juice. I’m mostly doing it so I can have better control on what product I use, and I can save the money. It’s a lot cheaper to buy a bottle of juice than buy separate pods”.
Another popular practice was to change different types of e-liquids. Participants mentioned that there are a lot of e-liquid options, which contain different flavors and various nicotine levels. Users often chose different flavors based on their personal tastes. Certain flavors that were perceived as better for ENDS devices and users’ health were also likely to be filled. Emily said, “We have some of the popular flavors that a majority of people will like, especially some of the juices that are less harsh on coils. And they’re made with all-natural flavorings. People tend to like that aspect of it, because they know they’re not getting a random chemical that tastes like this. It’s the actual fruit”. ENDS consumers also switch between different types of e-liquids so that they can control the amount of nicotine they vape and the throat hits. One product frequently mentioned was salt nicotine e-liquid. Compared to traditional e-liquids, salt nicotine e-liquids allow users to vape higher nicotine strengths while experiencing a less harsh throat hit [13
]. Due to its high nicotine content, it also mimics the sensation of smoking a combustible cigarette. Thus, many participants mentioned changing to a salt nicotine product.
Creating one’s own e-liquids was also commonly mentioned. Some users mixed different manufactured products to create the unique e-liquids they liked. Noah, for instance, mentioned that he mixed a watermelon-flavored e-liquid with a salt nicotine product, so that he can enjoy the high nicotine and the fruit flavor. In addition, some users added other substances in their e-liquids such as cannabidiol (CBD) and THC or marijuana. Participants mentioned that although there were no devices specifically designed for vaping CBD or THC, users had used “cartridge devices” or “dab pens” to vape those substances. The devices resemble a small pen with a cartridge at the top and a battery at the bottom. Users can take the top off and refill the cartridge with any type of e-liquids or install another cartridge that contains CBD or THC in it. Charlotte said, “I have CBD products that you would put into any of these devices, but specifically for a device made for that, no”. Jack mentioned, “There are some batteries which are cartridge devices, where people can put liquids which have THC in it, or, as you probably know, dab pens. These devices were not manufactured for that use, but a lot of people have used it in that sort of aspect”.
According to the interviewees, the major reason that they add CBD to their e-liquid is for medical purposes as CBD helps reduce their pain from physical conditions. Beth stated, “I use CBD because I have rheumatoid arthritis. So instead of taking all the medicine, I use the CBD oils every day to control my flare-ups with rheumatoid”. Other participants mentioned that they vaped to quit smoking, and CBD helped them overcome negative reactions to medical treatment. Charlotte said, “I got diagnosed with breast cancer, and I was a smoker. I knew I was going to have withdraws (withdrawals) from the nicotine. So I came and talked to the guys here, who are the guys that manage the store, and started vaping, and went to my chemo and started adding CBD on a regular basis to help me with the nausea, the vomiting, the being able to eat”.
3.2. Trend in Users’ Modifications to ENDS over Time
A change in the popularity of ENDS modifications emerged from the interviews. Specifically, participants underlined that ENDS modifications, especially modifications to coils and batteries, were more widespread a couple years ago, but today, a smaller proportion of users engaged in modifications. Jacob said, “Two or three years ago, even four years ago, the only option you had to run high wattage was to build your own course. That has changed. Not many people do any modifications. There is a small hobby group, but I mean small hobby group compared to the average person”. Alex also stated, “There’s still a market. There’re still people going to cloud competitions … but it’s very small niche now compared to where it was two years ago”.
Participants attributed the decline in ENDS modifications to the evolution of manufactured devices. As Emily mentioned, “The products that have the pre-made coils, which is the main thing you would modify in a device like that, have gotten so much better, that there’s really not a need to do that”. Similarly, Jacob said, “You don’t get a lot of edge out of building your own coils like you used to. Coils were so bad previously… now if it’s not a hobby, you’re not going to do it”. Moreover, Charlotte applauded her current device, “It’s rubberized. It’s waterproof. I mean they come up in style and you’re not going to break it”. Jack liked the small size of his JUUL, “So you can take one of those little devices and put it in your pocket and carry it easier… So the smaller the device, the easier it is to conceal and the easier it is to carry”.
Those examples demonstrated that instead of merely updating their products, the industry has actively developed new products and modified their designs so that they can fit and foster users’ various needs. Emily highlighted, “And they really revolutionized a lot of products on the market. And their products have always been really great products. Stand up to the test of time. They’re durable. … If there’s a need in the vaping market, they’ll try to find a product, or make a product to fit that need”. Ultimately, Jacob felt that “Yeah, you could ride a horse everywhere, but if you’ve got a car, you’re probably just going to drive”. In other words, while users’ ENDS modifications were still prevalent, industry-led modifications have increasingly dominated the market, making users’ modifications to coils and batteries less necessary.