An E-Liquid Flavor Wheel: A Shared Vocabulary Based on Systematically Reviewing E-Liquid Flavor Classifications in Literature

GC/HRMS Analysis of E-Liquids Complements In Vivo Modeling Methods and can Help to Predict Toxicity

Tobacco smoking is a major risk factor for disease development, with the user inhaling various chemicals known to be toxic. However, many of these chemicals are absent before tobacco is "burned". Similar, detailed data have only more recently being reported for the e-cigarette with regards to chemicals present before and after the e-liquid is "vaped." Here, zebrafish were dosed with vaped e-liquids, while C57-BL/6J mice were vaped using nose-cone only administration. Preliminary assessments were made using e-liquids and GC/HRMS to identify chemical signatures that differ between unvaped/vaped and flavored/unflavored samples. Oxidative stress and inflammatory immune cell response assays were then performed using our in vivo models. Chemical signatures differed, e.g., between unvaped/vaped samples and also between unflavored/flavored e-liquids, with known chemical irritants upregulated in vaped and unvaped flavored e-liquids compared with unflavored e-liquids. However, when possible respiratory irritants were evaluated, these agents were predominantly present in only the vaped e-liquid. Both oxidative stress and inflammatory responses were induced by a menthol-flavored but not a tobacco-flavored e-liquid. Thus, chemical signatures differ between unvaped versus vaped e-liquid samples and also between unflavored versus flavored e-liquids. These flavors also likely play a significant role in the variability of e-liquid characteristics, e.g., pro-inflammatory and/or cytotoxic responses.

Sex differences in appeal, reward, and sensory experience of E-cigarette flavors among adults who smoke cigarettes

OBJECTIVE

Flavors enhance nicotine e-cigarette appeal by altering sensory experience. Females may be more sensitive to tobacco-associated cues and uniquely affected by flavor. The current study is an exploratory analysis to examine differences by sex on reward, appeal, and sensory experience of popular e-cigarette flavors.

METHODS

Adults (N = 121) who use cigarettes (≥1 cigarette/day) were enrolled in a laboratory study in which they vaped four e-cigarette flavors (tobacco, cherry, menthol, vanilla; in separate lab sessions) in one of two freebase nicotine concentrations (6 mg/ml,18 mg/ml). Following exposures, participants rated e-cigarette reward using the Drug Effects Questionnaire (DEQ), flavor and overall e-cigarette appeal using Labeled Hedonic Scales (LHS), and intensity of flavor, irritation, coolness, fruitiness, and sweetness using Generalized Labeled Magnitude Scales (gLMS). Linear mixed models were conducted for outcomes to analyze effects of sex, flavor, and sex x flavor interaction.

RESULTS

For DEQ ratings, there was a trend (p = .08) toward a sex x flavor interaction, in which menthol flavor produced more reward than other flavors for females, but not males. For LHS ratings, there was a significant sex x flavor interaction (p = .03) for overall e-cigarette experience with females but not males rating menthol higher than other flavors. All gLMS scales but irritation showed that females generally had greater differences between flavors compared to males (ps ≤ 0.03).

CONCLUSION

Menthol in e-cigarettes may play an important role in mediating appeal and/or reward among females. This may be due in part to their ability to better detect sensory effects of e-cigarettes.

Labelling and composition of contraband electronic cigarettes: Analysis of products from Australia

BACKGROUND

The sale of nicotine-containing electronic cigarettes (e-cigarettes) is prescription only in Australia, regulated under the Standard for Nicotine Vaping Products (TGO110). Australian e-cigarette users, however, are purchasing e-cigarette products outside of the intended pathways.

METHODS

The labelling of e-cigarette packaging (N = 388 boxes) and the chemical composition of disposable e-cigarettes and pods (N = 428) were analysed for adherence to the current Australian regulations. These samples were confiscated from over-the-counter retailers in NSW by the NSW Ministry of Health during 2022 for non-compliance with Australian regulations.

RESULTS

Following the announcement of the prescription only model for nicotine-containing e-cigarettes in Australia in mid-2021 there was a clear shift in the labelling of products. Any mention of the word 'nicotine' was removed from e-cigarette packaging by early 2022 and nicotine warnings were replaced with generic underage sale warnings. Despite this labelling, the vast majority (98.8 %) of devices analysed contained nicotine, most (89 %) at high concentration (>30 mg/mL) and 4.2 % contained at least one chemical prohibited by the TGO110.

CONCLUSIONS

It appears that manufacturers have removed any mention of nicotine from the original packaging of nicotine-containing disposable e-cigarettes to circumvent restrictions on nicotine-containing products and continue their sale. The packaging of e-cigarette products in Australia is generally not indicative of their contents, particularly nicotine, and most did not display required warnings. Ingredients with associated health risks, prohibited in legal vapes by the TGO110, were found in samples. Consequently, the risks of e-cigarette use cannot be appropriately identified from the information supplied on the packaging or device.

Development of a Flavor Ingredient Wheel Linking E-Liquid Additives to the Labeled Flavor of Vaping Products

E-liquids contain combinations of chemicals, with many enhancing the sensory attractiveness of the product. Studies are needed to understand and characterize e-liquid ingredients, particularly flavorings, to inform future research and regulations of these products. We identified common flavor ingredients in a convenience sample of commercial e-liquids using gas chromatography-mass spectrometry. E-liquid flavors were categorized by flavor descriptors provided on the product packaging. A Flavor Ingredient Wheel was developed to link e-liquid flavor ingredients with flavor categories. An analysis of 109 samples identified 48 flavor ingredients. Consistency between the labeled flavor and ingredients used to produce such flavor was found. Our novel Flavor Ingredient Wheel organizes e-liquids by flavor and ingredients, enabling efficient analysis of the link between ingredients and their flavor profiles and allowing for quick assessment of an e-liquid ingredient's flavor profile. Investigating ingredient profiles and identifying and classifying commonly used chemicals in e-liquids may assist with future studies and improve the ability to regulate these products.

Does sensation-seeking behavior influence the patterns of flavored e-cigarette use? A cross-sectional study among Indonesian adolescents and young adults

BACKGROUND

The variety of available flavors in e-cigarettes may be a driver for young people to start using these products. The objectives of our study were to examine the relationship between sensation-seeking behavior and e-cigarette use, and to identify the predictors of flavor use patterns among adolescents in Indonesia.

METHODS

Students aged 15 to 24 years participated from randomly selected high schools and universities in Indonesia. Participants answered questions about their demographic data, e-cigarette use, conventional cigarette use, and sensation-seeking. Flavor preferences were identified from eight different flavor categories. Multivariate multinomial regression analysis was employed to predict conventional cigarette and e-cigarette use among students. A latent class analysis was conducted to determine the number of latent classes of flavor use.

RESULTS

One thousand six hundred high school and university students, with a mean age of 18.2 years (SD 2.19), were recruited between March and August, 2023. Conventional cigarette use in the past 30 days was higher (16.3%) compared to e-cigarette use (13.3%, p = 0.017), with approximately 8.5% of students were being dual users. Higher levels of sensation-seeking significantly increased the odds of being a current e-cigarette user (OR = 2.54, 95%CI 1.99-3.25) and a current conventional cigarette smoker (OR = 2.38, 95%CI 1.85-3.07). Three groups of flavor classes were identified: 1) primarily menthol flavor users (14%), who had a strong association with current conventional cigarette use; 2) experimenters, who mostly preferred fruit-flavored e-cigarettes (76%); and 3) the multi-flavor user group (10%), who had a higher sensation-seeking tendency.

CONCLUSIONS

Flavors, especially menthol and fruit flavors, attract youth, broaden the e-cigarette audience and are particularly appealing to high sensation-seekers. Banning these flavors could significantly deter e-cigarette initiation among youth.

Across the world availability of flavour accessories for tobacco products

OBJECTIVE

This study aimed to provide an inventory of different types of flavour accessories for combustible tobacco products in eight countries varying in their approaches to flavour legislation and cultural aspects, including tobacco use.

METHODS

A standardised search protocol was developed and shared with local informants to acquire information on the availability and marketing of flavour accessories in web shops accessible from Brazil, India, Italy, Singapore, South Africa, Switzerland, the UK and the USA. Characteristics of the products and web shops were reported, and flavours were categorised in a flavour wheel.

RESULTS

Flavour accessories were available in all participating countries. Reported types are flavour capsules, cards, filter tips and tubes for make-your-own cigarettes, drops, sprays, rolling paper, aroma markers, a flavour stone and a flavour powder. In total, 118 unique flavours were reported, which were mostly fruity and sweet. Marketing of these products was often associated with (menthol) flavour bans.

CONCLUSIONS

The wide availability and variety of flavour accessories raise significant public health concerns, as they have attractive flavours, and thus hinder the regulatory aim of flavour bans. Flavour accessories are not tobacco products and thus not regulated as such. Therefore, it is recommended that policymakers include these products in comprehensive flavour bans, to close this loophole in existing tobacco control measures.

Reducing attractiveness of e-liquids: proposal for a restrictive list of tobacco-related flavourings

OBJECTIVE

Electronic cigarettes are addictive and harmful, and flavour is a key factor determining their abuse liability. Both adult smokers and young non-smokers like sweet and fruity flavours in particular. In order to discourage e-cigarette use among youth, the Dutch government announced in 2020 to only allow tobacco flavours in e-liquids. We propose a restrictive list of flavourings that will only enable the production of e-liquids with a tobacco flavour.

METHODS

We used e-liquid ingredient data notified via the European Common Entry Gate system before the government's announcement. First, we classified all e-liquids into flavour categories, and continued with the set of flavourings present in tobacco e-liquids. Five selection criteria related to prevalence of use, chemical composition, flavour description and health effects were defined to compile a restrictive list of tobacco flavourings.

RESULTS

E-liquids marketed as having tobacco flavour contained 503 different flavourings, some with tobacco flavour, but also other (such as sweet) flavours. We excluded (1) 330 flavourings used in <0.5% of e-liquids, (2) 77 used less frequently in tobacco than in all e-liquids, (3) 13 plant extracts, (4) 60 that are sweet or not associated with a tobacco flavour and (5) 7 flavourings with hazardous properties. This resulted in a final list of 16 flavourings.

CONCLUSIONS

Implementing this restrictive list will likely discourage e-cigarette use among youth, but could also make e-cigarettes less attractive as smoking cessation aid.

Decisions of the FDA on premarket tobacco product applications: Changes in the number of unique devices and liquids used by US adults who frequently use electronic nicotine delivery systems, 2020-2023

INTRODUCTION

The majority of decisions on electronic nicotine delivery system (ENDS) premarket tobacco product applications (PMTAs) were made from October 2020 to February 2023; 99% (>25 million) had determinations by March 2023 and just twenty-three received marketing granted orders. We examined the unique devices and liquids used among US adults frequently using ENDS before, during, and after a majority of PMTA decisions were made.

METHODS

Data are from waves 1-5 (W1: May-Oct 2020, n=1179; W5: Feb-Apr 2023, n=1290) of a longitudinal survey of US adults (≥21 years) using ENDS ≥5 days/week. User-submitted photos of participants' most used devices and liquids were coded. Descriptive analyses and Wilcoxon signed-rank tests were used to understand the number and types of unique devices and liquids used in W1-W5, and the top brands in each wave.

RESULTS

From W1-W5, the number of unique ENDS device models and liquid products used by participants increased from 279 to 357 (p<0.001) and 546 to 695 (p<0.001), respectively. More unique devices in W5 versus W1 were disposable (W1: 16.5%; W5: 36.1%); fewer were disposable pod (W1: 6.5%; W5: 3.1%) or tank (W1: 53.8%; W5: 30.8%) devices. Liquids were primarily sweet-flavored (W1: 81.1%; W5: 82.0%). The median liquid nicotine concentration increased from 12 to 50 mg/mL. In W5, few participants used FDA-approved devices (n=17; 1.3%) or liquids (n=6; 0.5%), and Elf Bar was the most commonly used device and liquid brand. Results for all waves are reported.

CONCLUSIONS

Despite PMTA decisions, an increase in the number of unique device models and liquid products used among adults who frequently use ENDS was observed from 2020 to 2023. Few participants in 2023 were using FDA-approved devices or liquids. Further research and monitoring are needed to inform how FDA prioritizes enforcement actions and what types of enforcement actions are effective.

Electronic nicotine delivery system: a narrative review on growing threat to tobacco control and health of the young Indian population

The electronic cigarette (EC) was developed as an alternative to cigarette smoking. In less than a decade, the prevalence of past-month EC usage increased from 1.5 to 27.5 % among US high-school students. In the coming years, Asia-Pacific countries will have the highest sales of electronic nicotine/non-nicotine delivery systems (ENDS/ENNDS) after Western Europe. Based on the World Health Organization and Indian Council of Medical Research recommendations, India approved a complete ban on EC in 2019. Even though it has been three years since the ban, EC is still being sold in India's grey markets, where marketing is not regulated. In this narrative review, we discuss that vaping is not just a harm reduction strategy for tobacco smoking cessation but poses a serious threat to India's existing tobacco control efforts as well as the health of the country's young people.

Recent advances in the analysis of electronic cigarette liquids and aerosols: Sample preparation and chromatographic characterization

Electronic cigarette (e-cigarette) usage has risen dramatically worldwide in recent years. It has been publicized as a safer alternative to the conventional combustible cigarette. This, however, has not yet been supported by robust toxicological research evidence. Analysis of the chemical compositions of e-liquids and generated aerosols is an important step in evaluating the toxicity effects of e-cigarettes. Currently, a broad spectrum of analytical methods have been employed for qualitative and quantitative analysis of chemical compositions of e-cigarette liquids and aerosols. The aim of this article is to review the advances in the chromatographic characterization of chemical composition of the latter in the recent five years. In addition, sample preparation methods for e-liquids and aerosols are surveyed and discussed. A study of the relevant literature indicates that, expectedly, gas chromatography and liquid chromatography with a variety of detection systems, particularly mass spectrometry, have been the main analytical techniques used in this field. Sample preparation procedures primarily include headspace sampling, dilute-and-shoot approach, liquid-liquid extraction and sorbent-based extraction for e-liquids and for aerosols (the latter usually with laboratory-built collection devices). Some challenges of current e-cigarette analytical research, and an overview on prospective work are also presented.

E-Cigarettes and Associated Health Risks: An Update on Cancer Potential

The potential cancer risk associated with electronic-cigarette (e-cigarette) use is ongoing and remains a subject of debate. E-Cigarettes work by heating a liquid that usually contains nicotine, flavorings, and other chemicals. When the liquid is heated, users inhale an aerosol into their lungs. While e-cigarettes are generally considered less harmful than traditional tobacco products, they still contain potentially harmful chemicals, which can damage DNA and lead to cancer. Several studies have investigated the potential cancer risk associated with e-cigarette use, while other studies have suggested that e-cigarette aerosol may contain carcinogenic chemicals that could increase the risk of lung and bladder cancer in humans. However, these studies are limited in their scope and do not provide conclusive evidence. Overall, the long-term cancer risk associated with e-cigarette use remains uncertain, more research is needed to fully understand the potential risks and benefits of e-cigarettes. However, this review will allow the investigator to get more recent updates about e-cigarettes.

Adverse Biophysical Impact of e-Cigarette Flavors on Pulmonary Surfactant

The attractiveness and abundance of flavors are primary factors eliciting youth to use e-cigarettes. Emerging studies in recent years revealed the adverse health impact of e-cigarette flavoring chemicals, including disruption of the biophysical function of pulmonary surfactants in the lung. Nevertheless, a comprehensive understanding of the biophysical impact of various flavoring chemicals is still lacking. We used constrained drop surfactometry as a new alternative method to study the biophysical impact of flavored e-cigarette aerosols on an animal-derived natural pulmonary surfactant. The dose of exposure to e-cigarette aerosols was quantified with a quartz crystal microbalance, and alterations to the ultrastructure of the surfactant film were visualized using atomic force microscopy. We have systematically studied eight representative flavoring chemicals (benzyl alcohol, menthol, maltol, ethyl maltol, vanillin, ethyl vanillin, ethyl acetate, and ethyl butyrate) and six popular recombinant flavors (coffee, vanilla, tobacco, cotton candy, menthol/mint, and chocolate). Our results suggested a flavor-dependent inhibitory effect of e-cigarette aerosols on the biophysical properties of the pulmonary surfactant. A qualitative phase diagram was proposed to predict the hazardous potential of various flavoring chemicals. These results provide novel implications in understanding the environmental, health, and safety impacts of e-cigarette aerosols and may contribute to better regulation of e-cigarette products.

Environmental persistence, bioaccumulation, and hazards of chemicals in e-cigarette e-liquids: short-listing chemicals for risk assessments

BACKGROUND/METHODS

Increased use and sales of e-cigarettes raises concerns about the potential environmental impacts throughout their life-cycle. However, few available research studies focus on the environmental impacts and ecotoxicity of e-cigarettes. In this study, we short-list e-liquid chemicals from published literature that should be considered in future environmental impact and risk assessments. We used a combination of available laboratory bioassays-based data and predictive methods (eg, Structure-Activity Relationships) to characterise the hazards of the e-liquid chemicals (environmental persistence, bioaccumulation, and aquatic toxicity including hazardous concentration values (concentration affecting specific proportion of species)) for short-listing.

RESULTS

Of the 421 unique e-liquid chemicals compiled from literature, 35 are US Environmental Protection Agency's hazardous constituents, 42 are US Food and Drug Administration's harmful or potentially harmful constituents in tobacco products and smoke, and 20 are listed as both. Per hazard characteristics, we short-listed 81 chemicals that should be considered for future environmental impact and risk assessments, including tobacco-specific compounds (eg, nicotine, N'-nitrosonornicotine), polycyclic aromatic hydrocarbons (eg, chrysene), flavours (eg, (-)caryophyllene oxide), metals (eg, lead), phthalates (eg, di(2-ethylhexyl)phthalate) and flame retardants (eg, tris(4-methylphenyl)phosphate).

IMPLICATIONS

Our findings documenting various hazardous chemicals in the e-liquids underscore the importance of awareness and education when handling or disposing of e-liquids/e-cigarettes and aim to inform strategies to prevent and reduce hazards from e-cigarettes. This includes any scenario where e-liquids can come into contact with people or the environment during e-liquid storage, manufacturing, use, and disposal practices. Overall, our study characterises the environmental hazards of e-liquid chemicals and provides regulators and researchers a readily available list for future ecological and health risk assessments.

Transitions in device and liquid characteristic groupings among US adults frequently using electronic nicotine delivery systems (ENDS) over three timepoints, 2020-2021

INTRODUCTION

Electronic nicotine delivery system (ENDS) and liquid characteristics affect nicotine and toxicant exposure and use behaviors. Little is known about how adults who frequently use ENDS transition between ENDS device/liquid groupings.

METHODS

A total of 379 US adults (≥21 years) using ENDS frequently (≥5 days/week) self-reported and uploaded photos of their most used ENDS device and liquid in three waves of online surveys (May 2020 - November 2021). Device/liquid grouping was defined by device (i.e. disposable/refillable tank/refillable pod or cartridge/disposable pod or cartridge, adjustable/no adjustable settings) and liquid (i.e. salt/freebase) characteristics. Participants using the same grouping across waves were considered stable users.

RESULTS

The most prevalent wave (W) 1 grouping was tank (freebase, adjustable settings; 36.8%). From W1 to W3, the number of disposable device (salt, no adjustable settings) users increased 156.4% and the number of disposable pod/cartridge (salt, no adjustable settings) users decreased 15.2%. In W2 and W3, compared to stable users, participants using tank (freebase, adjustable settings) in W1 and another grouping in W2 and/or W3 reported significantly higher nicotine concentrations (mg/mL) (W2: 15.1 vs 5.5, p<0.001; W3: 22.9 vs 5.6, p<0.001) and lower device power (watt) (W2: 46.8 vs 58.7, p=0.02; W3: 34.0 vs 57.2, p<0.001).

CONCLUSIONS

Over a 1.5-year period, a rapid growth in disposable device (salt, no adjustable settings) use and a decrease in disposable pod/cartridge (salt, no adjustable settings) use were observed. Participants who transitioned from tank (freebase, adjustable settings) to other groupings were more likely to increase liquid nicotine concentration and reduce device power compared to stable users.

Flavored Cannabis Use and Cannabis-Tobacco Co-use: Patterns In U.S. States With Legalized Nonmedical Adult Use

INTRODUCTION

Little is known about inhaled flavored cannabis use. This study aimed to investigate the prevalence and patterns of flavored cannabis use and cannabis-tobacco co-use.

METHODS

This study surveyed adult past 30-day cannabis users in U.S. states and districts that have legalized cannabis for nonmedical/adult use (n=9) (November 2018; n=2,978). By product/behavior (any cannabis, cannabis extract vaporizers, mixed cannabis-nicotine vaporizers, blunts, chasing), the association between flavored (versus non-flavored) use and sociodemographic characteristics, cannabis use disorder symptoms, and tobacco use was estimated using weighted multivariable logistic regression in January 2022.

RESULTS

Almost half of adult cannabis users reported using at least one flavored cannabis product (46.5%). Flavored cannabis use was more likely among respondents who were female (AOR=1.2, CI=1.0, 1.4), were Black (ref: White; AOR=2.2, CI=1.5, 3.1), were Hispanic/Latino/a/x (ref: White; AOR=1.6, CI=1.2, 1.9), had cannabis use disorder symptoms (AOR=2.0, CI=1.6, 2.4), or were currently using tobacco (AOR=2.4, CI=2.1, 2.9). Use was less likely among middle-aged/older adults (ref: ages 21-34 vs 35-49 years; AOR=0.6, CI=0.5, 0.7).

CONCLUSIONS

Observed differences in flavored cannabis use are concerning if flavors raise appeal or dependence. Integrating flavored cannabis and tobacco research and practice is warranted.

Oral nicotine pouches with an aftertaste? Part 2: in vitro toxicity in human gingival fibroblasts

Nicotine pouches contain fewer characteristic toxicants than conventional tobacco products. However, the associated risks in terms of toxicity and addiction potential are still unclear. Therefore, endpoints of toxicity and contents of flavoring substances were investigated in this study. The in vitro toxicity of five different nicotine pouches and the reference snus CRP1.1 were studied in human gingival fibroblasts (HGF-1). Cells were exposed to product extracts (nicotine contents: 0.03-1.34 mg/mL) and sampled at different time points. Cytotoxicity, total cellular reactive oxygen species (ROS) levels, and changes in the expression levels of inflammatory and oxidative stress genes were assessed. Flavor compounds used in the nicotine pouches were identified by GC-MS. Cytotoxicity was observed in two nicotine pouches. Gene expression of interleukin 6 (IL6) and heme oxygenase 1 (HMOX1) was upregulated by one and three pouches, respectively. ROS production was either increased or decreased, by one pouch each. CRP1.1 caused an upregulation of IL6 and elevated ROS production. Toxicity was not directly dependent on nicotine concentration and osmolarity. A total of 56 flavorings were detected in the five nicotine pouches. Seven flavorings were classified according to the harmonized hazard classification system as laid down in the European Classification, Labelling and Packaging regulation. Nine flavorings are known cytotoxins. Cytotoxicity, inflammation, and oxidative stress responses indicate that adverse effects such as local lesions in the buccal mucosa may occur after chronic product use. In conclusion, flavorings used in nicotine pouches likely contribute to the toxicity of nicotine pouches.

In Vitro high-throughput toxicological assessment of E-cigarette flavors on human bronchial epithelial cells and the potential involvement of TRPA1 in cinnamon flavor-induced toxicity

Electronic cigarettes (ECs) are considered a less hazardous alternative to tobacco smoking but are not harmless. Growing concerns about the safety profiles of flavors in e-liquids underpin the need for this study. Here, we screened 53 nicotine-free flavored e-liquids (across 15 flavor categories) across a 3-point concentration range (0.25%, 0.5%, and 1% v/v) in a high-throughput fashion in human bronchial epithelial (HBEC-3KT) submerged cell cultures to identify 'toxic hits' using in vitro endpoint assays comprising cell count, cell viability, and lactate dehydrogenase (LDH). We observed significant, dose-dependent adverse effects only with cinnamon, vanilla tobacco, and hazelnut e-liquids compared to media-only and PG/VG vehicle controls. Hence, we further analyzed these three flavors for their effects on HBEC-3KT proliferation, mitochondrial health, and oxidative stress. A significant decrease in cell proliferation after 36 h was observed for each e-liquid toxic hit compared to media-only and PG/VG controls. Hazelnut (at all concentrations) and vanilla tobacco (1%) increased cytoplasmic reactive oxygen species generation compared to media-only and PG/VG controls. Conversely, all three flavors at 0.5% and 1% significantly decreased mitochondrial membrane potential compared to PG/VG and media-only controls. Chemical analysis revealed that all three flavors contained volatile organic compounds. We hypothesized that the cytotoxicity of cinnamon might be mediated via TRPA1; however, TRPA1 antagonist AP-18 (10 μM) did not mitigate these effects, and cinnamon significantly increased TRPA1 transcript levels. Therefore, pathways mediating cinnamon's cytotoxicity warrant further investigations. This study could inform public health authorities on the relative health risks assessment following exposure to EC flavor ingredients.

Oral nicotine pouches with an aftertaste? Part 1: screening and initial toxicological assessment of flavorings and other ingredients

Nicotine pouches are oral products that deliver nicotine without containing tobacco. Previous studies mainly focused on the determination of known tobacco toxicants, while yet no untargeted analysis has been published on unknown constituents, possibly contributing to toxicity. Furthermore, additives might enhance product attractiveness. We therefore performed an aroma screening with 48 different nicotine-containing and two nicotine-free pouches using gas chromatography coupled to mass spectrometry, following acidic and basic liquid-liquid extraction. For toxicological assessment of identified substances, European and international classifications for chemical and food safety were consulted. Further, ingredients listed on product packages were counted and grouped by function. Most abundant ingredients comprised sweeteners, aroma substances, humectants, fillers, and acidity regulators. 186 substances were identified. For some substances, acceptable daily intake limits set by European Food Safety Agency (EFSA) and Joint FAO/WHO Expert Committee on Food Additives are likely exceeded by moderate pouch consumption. Eight hazardous substances are classified according to the European CLP regulation. Thirteen substances were not authorized as food flavorings by EFSA, among them impurities such as myosmine and ledol. Three substances were classified by International Agency for Research on Cancer as possibly carcinogenic to humans. The two nicotine-free pouches contain pharmacologically active ingredients such as ashwagandha extract and caffeine. The presence of potentially harmful substances may point to the need for regulation of additives in nicotine-containing and nicotine-free pouches that could be based on provisions for food additives. For sure, additives may not pretend positive health effects in case the product is used.

Flavours and flavourings in waterpipe products: a comparison between tobacco, herbal molasses and steam stones

ObjectivesFlavoured products are especially appealing to youth and contribute to the onset of waterpipe smoking and continued use of waterpipe tobacco. The goal of database and chemical analysis was to provide a clear overview of commonly used flavours and flavourings in tobacco and related waterpipe products, that is, herbal molasses and steam stones.

METHODS

In 2019, 249 waterpipe tobacco products were registered in the European Common Entry Gate by manufacturers to be marketed in The Netherlands. Flavour categories were assigned to the registered products based on their brand names and product descriptions. Nicotine and eleven 1111 flavourings were identified and quantified in waterpipe tobacco (n=8), herbal molasses (n=7) and steam stones (n=4) by extraction and gas chromatography-mass spectrometry (GC-MS) analysis.

RESULTS

Flavour categories could be assigned to 237 of 249 registered waterpipe tobacco products. Eight flavour main categories and 48 unique subcategories were identified and presented in a flavour wheel. All registered waterpipe tobacco products were flavoured, and the majority (78%) was fruit flavoured. Herbal molasses contained similar median flavouring levels, and steam stones contained lower median levels compared with waterpipe tobacco. Flavourings in waterpipe products were almost exclusively fruity and sweet, often in combination with menthol/mint flavourings.

CONCLUSIONS

This study is the first to present a waterpipe tobacco flavour wheel, providing a quick overview of waterpipe tobacco flavours and thereby aiding communication among experts around the globe. GC-MS analysis revealed that the most prevalent flavourings are present in similar levels in herbal and tobacco waterpipe products. Banning flavourings in all waterpipe products would be a good strategy to reduce waterpipe smoking among youth.

Device and liquid characteristics used with sweet, menthol/mint, and tobacco ENDS liquid flavors: The population-based VAPER study

INTRODUCTION

Electronic nicotine delivery system (ENDS) device and liquid characteristics (e.g., wattage, nicotine concentration) are diverse and important in determining product appeal, aerosol volume/nicotine levels, and toxicity. Little is known about how device and liquid characteristics vary by flavor; we address this gap to identify potential regulatory implications.

METHODS

Data are from a longitudinal cohort study (Waves 2 and 3; December 2020-December 2021) of adult (≥21 years) U.S. ENDS users (≥5 days of use/week). Participants (n = 1809) reported on and submitted photos of their most used device and liquid. Participants were categorized into flavor groups of high prevalence in our sample and in prior literature: sweet, menthol/mint, or tobacco. Participants using liquids without nicotine or flavors other than sweet, menthol/mint, or tobacco were excluded (n = 320). Data were analyzed cross-sectionally. Chi-square and linear regression (n = 1489) were used to examine device and liquid characteristics by flavor.

RESULTS

Sweet flavors were most common (n = 1135; 76.2%), followed by menthol/mint (n = 214, 14.4%) and tobacco (n = 140, 9.4%). Sweet flavors were less common among participants using reusable devices with disposable pods/cartridges (nicotine salt) than those using other device-liquid groupings (5.2% vs 86.5-93.9%; p < 0.001). Sweet flavors were less common among those using ENDS for non-flavor reasons vs the flavor (73.5% vs 90.4%; p < 0.001). Sweet flavors correlated with lower nicotine concentrations, higher wattages, and lower ages of ENDS first use (p < 0.001).

CONCLUSIONS

Regulatory agencies must consider how regulations on device and liquid characteristics may affect ENDS users' behaviors (e.g., limiting availability of sweet flavors may encourage use of non-sweet flavors and lower wattages).

Heavy metals in ENDS: a comparison of open versus closed systems purchased from the USA, England, Canada and Australia

INTRODUCTION

Electronic nicotine delivery systems (ENDS) are known to contain heavy metals such as lead (Pb), nickel (Ni) and chromium (Cr). The presence of heavy metals in ENDS may be due to contamination of e-liquids or leaching from elements of the ENDS device. This study investigates differences in ENDS metal concentrations between product type, year of purchase, country of purchase and e-liquid flavour.

METHODS

Various open-system (refill e-liquids; n=116) and closed-system (prefilled with e-liquid; n=120) products were purchased in 2017 and 2018 from the USA, England, Canada and Australia. Electrothermal atomic absorption spectroscopy was used to analyse each product for Pb, Ni and Cr. Multiple linear regression and Kruskal-Wallis non-parametric statistical tests were conducted using GraphPad.

RESULTS

Linear regression showed system type, year of purchase (not supported by Kruskal-Wallis), country of purchase and flavour type each had significant impacts on heavy metal concentrations. Open-system e-liquid samples showed no quantifiable levels of heavy metals. Closed-system samples contained concerningly high concentrations of Pb, Ni and Cr. Closed-system samples from the USA commonly displayed higher average heavy metal concentrations than those from England. Some fruit and mint-flavoured closed-system products showed higher heavy metal concentrations than tobacco-flavoured products.

CONCLUSION

The presence of heavy metals only in closed-system products suggests that metals may be leaching from ENDS device parts. Highly variable heavy metal concentrations between ENDS products demonstrate that various product characteristics may affect the degree of leaching and that there is a need for further regulation of these products.

Presence of flavoured electronic nicotine delivery system (ENDS) products in US ENDS advertisements, 2015-2020: a content analysis

OBJECTIVES

Electronic nicotine delivery systems (ENDS) products come in a variety of flavours (eg, fruit, dessert, menthol). Tobacco advertising has historically used flavours as an advertising tactic, but little is known about flavour type and prevalence in ENDS advertisements. We assess the presence of flavoured ENDS in ads over time, by media outlet (eg, magazines, online) and brand.

METHODS

We acquired ENDS ads (N=4546) that first ran between 2015-2017 (n=1685; study 1) and 2018-2020 (n=2861; study 2) in outlets including opt-in emails, direct-to-consumer mail (study 1 only), video (TV and online), radio (study 2 only), static online/mobile (ie, ads without video or moving graphics), social media, outdoor (eg, billboards; study 2 only) and consumer magazines. We coded for presence of flavoured ENDS products and flavour type (eg, fruit, tobacco, menthol) and merged this information with metadata on ad year, outlet and manufacturer/retailer brand.

RESULTS

Overall, nearly half (45.5%; n=2067) of ads in our sample featured a flavoured product. Tobacco (59.1%; n=1221), menthol (42.9%; n=887) and fruit (38.6%; n=797) were the most advertised flavours. Over time, the proportion of ads containing tobacco-flavoured and menthol-flavoured ENDS generally decreased before menthol rebounded in 2020. The proportion of ads containing fruit, mint and dessert flavours generally increased over time, with a substantive drop in 2020. We found notable differences in flavoured ENDS advertising by outlet and brand.

CONCLUSIONS

The overall presence of flavoured ENDS in our sample of ads remained relatively consistent, with tobacco flavour decreasing over time and some non-tobacco flavours increasing over time until 2020 when the presence decreased.

The associations between e-liquid characteristics and its pricing: Evidence from online vape shops

Given the increase in electronic cigarette use during the past decade, the objectives of this study are to obtain comprehensive product-level information from online vape shops, which are one of the most common outlets for e-cigarette users to purchase vaping products, especially e-liquid products, and to examine the appeal of various e-liquid product attributes to consumers. We used web scraping and estimation of generalized estimating equation (GEE) models to obtain and analyze data from five popular online vape shops that sell nationwide across the US. The outcome measures are e-liquid pricing for the following e-liquid product attributes: nicotine concentration (in mg/ml), nicotine form (nicotine-free, freebase, or salt), vegetable glycerin/propylene glycol (VG/PG) ratio, and a variety of flavors. We find that the pricing for freebase nicotine and nicotine salt products are 1% (p<0.001) lower and 12% higher (p<0.001), respectively, than that for products that do not contain nicotine. For nicotine salt-based e-liquid products specifically, the pricing for a 50/50 VG/PG ratio is 10% (p<0.001) higher than the pricing for a more common 70/30 VG/PG ratio, and the pricing for fruity flavors is 2% (p<0.05) higher than that for tobacco/unflavored products. Regulating the nicotine form in all e-liquid products and fruity flavor in nicotine salt-based products will have a great impact on the market and consumers. The preference for VG/PG ratio varies by product nicotine form. More evidence on typical user patterns of a certain nicotine form (i.e., freebase or salt nicotine) is needed to assess the public health consequences of these regulations.

Vaping Dose, Device Type, and E-Liquid Flavor are Determinants of DNA Damage in Electronic Cigarette Users

INTRODUCTION

Despite the widespread use of electronic cigarettes, the long-term health consequences of vaping are largely unknown.

AIMS AND METHODS

We investigated the DNA-damaging effects of vaping as compared to smoking in healthy adults, including "exclusive" vapers (never smokers), cigarette smokers only, and nonusers, matched for age, gender, and race (N = 72). Following biochemical verification of vaping or smoking status, we quantified DNA damage in oral epithelial cells of our study subjects, using a long-amplicon quantitative polymerase chain reaction assay.

RESULTS

We detected significantly increased levels of DNA damage in both vapers and smokers as compared to nonusers (p = .005 and p = .020, respectively). While the mean levels of DNA damage did not differ significantly between vapers and smokers (p = .522), damage levels increased dose-dependently, from light users to heavy users, in both vapers and smokers as compared to nonusers. Among vapers, pod users followed by mod users, and those who used sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, showed the highest levels of DNA damage. The nicotine content of e-liquid was not a predictor of DNA damage in vapers.

CONCLUSIONS

This is the first demonstration of a dose-dependent formation of DNA damage in vapers who had never smoked cigarettes. Our data support a role for product characteristics, specifically device type and e-liquid flavor, in the induction of DNA damage in vapers. Given the popularity of pod and mod devices and the preferability of sweet-, mint or menthol-, and fruit-flavored e-liquids by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

IMPLICATIONS

We demonstrate a dose-dependent formation of DNA damage in oral cells from vapers who had never smoked tobacco cigarettes as well as exclusive cigarette smokers. Device type and e-liquid flavor determine the extent of DNA damage detected in vapers. Users of pod devices followed by mod users, and those who use sweet-, mint or menthol-, and fruit-flavored e-liquids, respectively, show the highest levels of DNA damage when compared to nonusers. Given the popularity of pod and mod devices and the preferability of these same flavors of e-liquid by both adult- and youth vapers, our findings can have significant implications for public health and tobacco products regulation.

Flavour spectrum of the Puff family of disposable e-cigarettes

BACKGROUND

In January 2020, the US Food and Drug Administration prohibited the sale of flavours (except for menthol and tobacco) in prefilled pod devices such as JUUL to decrease youth vaping. Excluded from the prohibition were disposable devices.

OBJECTIVES

To determine the scope and scale of flavours marketed by Puff Bar, a leading disposable brand, and related products.

METHODS

Disposable e-cigarette flavours were identified via online searches encompassing vendor websites, wholesale distributors, manufacturers (eg, made-in-china.com), and social media channel, Instagram, between June and August 2020.

RESULTS

The 'Puff' brand name and iconic cloud logo appear on a variety of products of differing sizes and nicotine e-liquid volumes. Among Puff Bar and its copycats (Puff-a-Likes), 139 flavours were identified. Fruit flavours predominated comprising 82.2% of the flavour varieties (fruit 50%, fruit and menthol/mint 23.6%, and fruity drinks 8.6%). A prevalent new flavour category which combines fruit with menthol/mint (Ice) was offered in 33 varieties such as Lychee Ice, Lush Ice and Banana Ice. Disposable e-cigarette brands are undertaking measures to escape tobacco regulation (eg, non-tobacco-sourced nicotine) and flavour limitations via post-market flavour additions to unflavoured nicotine e-liquid.

CONCLUSIONS

The proliferation of flavoured disposable e-cigarette products, many of which are designed to emulate popular pod devices, illustrates that narrowly limited flavour regulations covering only a single category are destined to fail. To be effective in youth protection, flavour regulations need to apply to all recreational nicotine-containing products and need to include measures to counter post-market flavour addition.

Comprehensive Dutch market data analysis shows that e-liquids with nicotine salts have both higher nicotine and flavour concentrations than those with free-base nicotine

OBJECTIVES

Recent years have seen an increase in e-liquids containing nicotine salts. Nicotine salts are less harsh and bitter than free-base nicotine and therefore can facilitate inhalation. Because inhalation-facilitating ingredients are banned in the European Union, we assessed the occurrence and characteristics of nicotine salt-containing e-liquids notified for the Netherlands.

METHODS

We analysed data for 39 030 products, submitted by manufacturers in the European Union Common Entry Gate system, as extracted on 30 June 2020.

RESULTS

Nicotine salts were present in 13% of e-liquids, especially in pod-related e-liquids (73%) and e-liquids registered from 2018 onwards (over 25%). We found six nicotine salt ingredients (NSIs): nicotine lactate, salicylate, benzoate, levulinate, ditartrate and malate. Nicotine salts also occurred as nicotine-organic acid ingredient combination (NAIC), like nicotine and benzoic acid. Nicotine concentrations were twofold higher in e-liquids with NSI (median 14 mg/mL) and NAIC (11 mg/mL) than for free-base nicotine (6 mg/mL). E-liquids with NSI contained a fourfold higher number (median n=17) and concentration (median 31.0 mg/mL) of flavour ingredients than e-liquids with free-base nicotine (n=4, 7.4 mg/mL). In NAIC-containing e-liquids, these were threefold higher (n=12, 21.5 mg/mL). E-liquids with nicotine salts were less often tobacco flavoured but more often had fruity or sweet flavours.

CONCLUSIONS

A substantial and increasing share of e-liquids in the Netherlands contains nicotine salts. Their characteristics can make such e-liquids more addictive and more attractive, especially to young and beginning users. Policymakers are advised to consider regulating products containing nicotine salts.

Public Perceptions of Flavored Waterpipe Smoking on Twitter

Waterpipe tobacco smoking has become increasingly popular in recent years, especially among youth. We aimed to understand longitudinal trends in the prevalence and user perception of waterpipes and their flavors on Twitter. We extracted waterpipe-related tweets from March 2021 to May 2022 using the Twitter Streaming API and classified them into promotional tweets and non-promotional tweets. We examined the longitudinal trends regarding the waterpipe flavors mentioned on Twitter and conducted sentiment analysis on each waterpipe flavor-related non-promotional tweet. Among over 1.3 million waterpipe-related tweets, 1,158,884 tweets were classified as non-promotional and 235,132 were classified as promotional. The most frequently mentioned waterpipe flavor groups were fruit (34%), sweets (17%), and beverages (15%) among all flavor-containing non-promotional tweets (17,746 tweets). The least mentioned flavor groups were tobacco (unflavored, 4%) and spices (2%). Sentiment analysis showed that among non-promotional waterpipe-related tweets, 39% were neutral, 36% were positive, and 23% were negative. The most preferred waterpipe flavors were fruit, mixed, and alcohol flavors. The least preferred flavor groups were tobacco and spice flavors. Our study provided valuable information on the prevalence of waterpipe flavors that can be used to support the future regulation of flavored waterpipe tobacco products given the nature of the current regulations on other flavored tobacco products.

The Role of Flavored Electronic Nicotine Delivery Systems in Smoking Cessation: A Systematic Review

Background

Electronic nicotine delivery systems (ENDS) come in numerous flavors and may aid smoking cessation. This systematic review examines evidence on the role of ENDS flavors in smoking cessation.

Methods

We searched EMBASE OVID, PsychInfo, and Medline databases for studies that: 1) examined cigarette cessation outcomes for persons using ENDS (intent, attempts, and success) and 2) reported results separated by respondent's ENDS flavor used. We extracted crude and adjusted odds ratios for associations between cessation outcomes and types of ENDS flavors used (nontobacco vs. tobacco/unflavored; nontobacco and nonmenthol vs. tobacco/unflavored and menthol). We did not consider cessation outcomes among people not using ENDS. We evaluated the evidence using the GRADE approach, focusing on consistency and reliability of findings across studies.

Results

29 studies met inclusion criteria, producing 36 odds ratios (ORs) comparing cessation outcomes across ENDS flavor groups. Three ORs examined quit intent, five examined quit attempts, and 28 examined quit success. Using GRADE, we reached Low levels of certainty that there was not an association between ENDS flavor use and intention to quit smoking or making a quit attempt. There were Very Low levels of certainty that nontobacco flavored versus tobacco/unflavored ENDS use was not associated with smoking cessation success, with similar findings for nonmenthol and nontobacco compared to tobacco and menthol flavored ENDS.

Conclusion

The evidence about the role of different flavored ENDS use and smoking cessation outcomes is inconclusive, reflecting highly heterogeneous study definitions and methodological limitations. More high-quality evidence, ideally from randomized controlled trials, is required.

E-cigarette product preferences of Australian adolescent and adult users: a 2022 study

BACKGROUND

Research that comprehensively documents preferences for different types of novel nicotine products in Australia is lacking, making it difficult for policymakers to determine where public health efforts should be focused. This study thus sought to explore Australian adolescent and adult e-cigarette users' preferences for different types of e-cigarettes and e-liquids. Purchasing behaviours and sources of e-liquid were also examined.

METHODS

An online survey was administered to 4,617 Australians aged 12 + years, 636 of whom had used an e-cigarette in the last 30 days and were the focus of this study. Among users, 45% also smoked tobacco cigarettes, 41% were non-smokers, and 14% had never smoked.

RESULTS

The majority (82%) of e-cigarette users surveyed reported using nicotine-containing e-liquid in their devices. Fewer (60%) reported using non-nicotine e-liquid. The preference for nicotine over non-nicotine e-liquid was observed among all age and smoking groups. Most users (89%) reported using flavoured e-liquids, with adolescents (96%) significantly more likely than young adults (90%) and adults aged 25 + years (85%) to report using such e-liquids. Fruit flavours were the most popular among all subgroups. In terms of device type, disposable e-cigarettes were the most common product used among almost all groups; the exception being adults aged 25 + years who preferred systems with refillable tanks. Friends and tobacco retailers were the most frequently nominated sources of nicotine e-liquid among adolescents and young adults. Among adults aged 25 + years, tobacco retailers and the Internet were the most frequently nominated sources of these products.

CONCLUSION

Disposable e-cigarettes with flavoured, nicotine-containing e-liquid are popular among users of the devices, including adolescents. Measures that restrict the accessibility and availability of flavoured e-liquids and disposable e-cigarettes, and greater enforcement of laws regarding the sale and importation of nicotine e-liquids, are urgently needed to protect youth and never smokers from these products.

Characterizing different-flavored e-cigarette solutions from user-reported sensory attributes and appeal

Scientists and regulators need parsimonious methods of characterizing flavored e-cigarettes which may vary widely in both chemical flavoring constituents and marketing descriptors. This laboratory experiment characterized user-reported appeal and experience of five cross-cutting sensory attributes (sweetness, bitterness, smoothness, harshness, coolness) of 10 common e-cigarette flavors. In a within-subject double-blind single-visit protocol, current nicotine/tobacco product users (N = 119) self-administered a single puff of each e-liquid flavor via a pod-style device and rated its appeal and sensory attributes on 0-100 scales. Custom-manufactured e-liquids, nicotine concentration: M (SD) = 23.4 (0.9) mg/mL, representative of commonly marketed fruit (green apple, strawberry), dessert (dark chocolate, vanilla), mint (peppermint, spearmint), nonmint cooling (menthol, koolada), and tobacco (subtle tobacco, full-flavored tobacco) flavor descriptors were used and their constituents were independently analyzed. Results largely demonstrated that a flavor's sensory attributes concorded with its marketed flavor descriptor. Among the 10 flavors, vanilla was rated sweetest (B[difference vs. mean of 9 other flavors] = 14.44, 95% CI [10.84, 18.03]), full-flavored tobacco was most bitter, B = 8.34, 95% CI [4.73, 11.96], subtle tobacco was most harsh, B = 5.69, 95% CI [1.70, 9.68], and peppermint scored highest in both smoothness, B = 6.98, 95% CI [3.13, 10.82], and coolness, B = 29.25, 95% CI [25.50, 33.01]. Flavors with higher appeal ratings tended to be sweeter, smoother, cooler, and less bitter and harsh. Chemical analysis found numerous flavoring constituents among study products without any clear differentiation of chemicals being present in particular flavor categories, which underscores the utility of using sensory ratings to characterize different-flavored e-cigarettes over and above constituent analyses. Characterizing e-cigarette flavors by subjective sensory attributes may be useful in future research and regulatory activities. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Chemical Profiles and Toxicity of Electronic Cigarettes: An Umbrella Review and Methodological Considerations

BACKGROUND

Electronic cigarettes (ECs) are often marketed as a safer alternative to combustible tobacco products. The global EC market has rapidly expanded since their introduction, creating an urgent need for research describing the toxicity and chemical composition of ECs. We conducted an umbrella review to summarize the evidence from existing systematic reviews (SRs).

METHODS

The search for SRs was conducted across four electronic databases through 25 January 2022. Methodological quality was assessed using the AMSTAR-2 quality appraisal tool.

RESULTS

Twenty-five SRs were included in our umbrella review. Chemical profiles widely varied across studies included in the reviews, which was mainly attributed to the lack of standardized protocols investigating the constituents, and differences in EC devices and e-liquids tested. Metals were more abundant in some EC aerosols than cigarettes, while carbonyls were typically found at lower levels. There was consistent evidence of in vitro toxicity from EC aerosol and e-liquid exposure. AMSTAR-2 revealed important limitations across reviews.

CONCLUSIONS

While most reviews concluded that ECs were likely less harmful than cigarettes, there was hesitancy to draw clear conclusions due to variable analytical procedures and inconsistent findings among the included studies. Future SRs with improved methodology and reporting are needed to adequately inform tobacco regulatory actions.

E-cigarette Flavors, Sensory Perception, and Evoked Responses

The chemosensory experiences evoked by flavors encompass a number of unique sensations that include olfactory stimuli (smell), gustatory stimuli (taste, i.e., salty, sweet, sour, bitter, and umami (also known as "savoriness")), and chemesthesis (touch). As such, the responses evoked by flavors are complex and, as briefly stated above, involve multiple perceptive mechanisms. The practice of adding flavorings to tobacco products dates back to the 17th century but is likely much older. More recently, the electronic cigarette or "e-cigarette" and its accompanying flavored e-liquids emerged on to the global market. These new products contain no combustible tobacco but often contain large concentrations (reported from 0 to more than 50 mg/mL) of nicotine as well as numerous flavorings and/or flavor chemicals. At present, there are more than 400 e-cigarette brands available along with potentially >15,000 different/unique flavored products. However, surprisingly little is known about the flavors/flavor chemicals added to these products, which can account for >1% by weight of some e-liquids, and their resultant chemosensory experiences, and the US FDA has done relatively little, until recently, to regulate these products. This article will discuss e-cigarette flavors and flavor chemicals, their elicited responses, and their sensory effects in some detail.

Changes in product labelling practices and the use of flavouring chemical additives in vaping products after enactment of statewide flavour legislation

INTRODUCTION

On 18 May 2020, New York State enacted legislation banning the sale of vaping products with distinguishable flavours (other than tobacco). According to this new statute, vaping products are deemed flavoured if they include a statement, whether expressed or implied, that have distinguishable tastes or aromas other than tobacco. This study aimed to determine how manufacturers responded.

METHODS

We collected 555 vaping products from daily vapers (238 preban and 317 postban). We compared preban and postban labelling of products for expressed and implied flavour descriptions, graphics and colours. Flavouring chemicals and concentrations were identified using chromatography methods and were compared preban and postban.

RESULTS

Analysis of the labels preban and postban did not reveal a change in products with expressed flavoured descriptors (45.8% vs 44.2%) and a minimal decrease in implied descriptors (22.3% vs 14.5%). An increase in products without any descriptors was observed (28.2% vs 37.2%) notably within products from a popular pod brand. The average concentration of eight popular flavourings identified preban was 1.4±2.7 compared with 2.3±3.5 mg/mL (p<0.001) postban. No significant changes between individual flavouring concentrations in the most popular refill solutions and pods were found.

CONCLUSION

While a majority of products appeared to remain non-compliant, this study suggests that enactment of legislation on vaping products making expressed or implied flavour claims may result in some manufacturer changes to product labelling including removal of flavour descriptors. However, use of flavouring additives in vaping products appeared not to be impacted by the ban.

Expanding the E-Liquid Flavor Wheel: Classification of Emerging E-Liquid Flavors in Online Vape Shops

INTRODUCTION

Electronic cigarettes are the most popular tobacco product among U.S. youth, and over 80% of current youth users of e-cigarettes use flavored e-cigarettes, with fruit, mint/menthol, and candy/sweets being the most popular flavors. A number of new e-liquid flavors are currently emerging in the online e-cigarette market. Menthol and other flavored e-cigarettes could incentivize combustible tobacco smokers to transition to e-cigarette use.

METHODS

From February to May 2021, we scraped data of over 14,000 e-liquid products, including detailed descriptions of their flavors, from five national online vape shops. Building upon the existing e-liquid flavor wheel, we expanded the semantic databases (i.e., key terms) to identify flavors using WordNet-a major database for keyword matching and group discussion. Using the enriched databases, we classified 14,000+ e-liquid products into the following 11 main flavor categories: "fruit", "dessert/candy/sweets", "coffee/tea", "alcohol", "other beverages", "tobacco", "mint/menthol", "nuts", "spices/pepper", "other flavors", and "unspecified flavor".

RESULTS

We find that the most prominent flavor sold in the five online vape shop in 2021 was fruit flavored products, followed by dessert/candy/other sweets. Online vendors often label a product with several flavor profiles, such as fruit and menthol.

CONCLUSIONS

Given that online stores market products with multiple flavor profiles and most of their products contain fruit flavor, the FDA may have issued marketing denial orders to some of these products. It is important to further examine how online stores respond to the FDA flavor restrictions (e.g., compliance or non-compliance).

Pulmonary effects of e-liquid flavors: a systematic review

Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.

Discussion of waterpipe tobacco smoking on reddit

Objectives

This study aimed to examine public discussions of waterpipe tobacco smoking, as well as the potential associations of different waterpipe flavors with health symptoms, using Reddit data.

Study design

This is an observational infodemiology study.

Methods

Using keywords such as “waterpipe”, “hookah”, and “shisha”, Reddit posts were extracted from Reddit Archive (pushshift.io) between February 1, 2016, and December 31, 2020. Temporal analysis was used to understand the longitudinal trend of the discussions about waterpipe tobacco smoking. Topic modeling using the Latent Dirichlet Allocation (LDA) model was performed to examine the topics on waterpipe tobacco. We estimated the conditional probability of having each health problem for each given waterpipe flavor.

Results

The discussion of waterpipe on Reddit was slowly decreasing from 2016 to 2018 and surged until May 2020. The fruit was the most popular waterpipe flavor and the neurological symptom was the most mentioned health category in waterpipe-related Reddit posts. The most popular topics included “Friends spending time together at night with waterpipe smoking”, “Playing games and smoking waterpipe at a hookah bar”, and “Discussing waterpipe flavors and related products”. Some waterpipe flavors were more associated with certain health problems than others. For example, mint/menthol flavor had a high probability to be associated with symptoms related to throat and mouth.

Conclusion

This study provided longitudinal surveillance of waterpipe tobacco smoking discussed on Reddit. We showed the potential relationship between waterpipe flavors and health symptoms, which provides preliminary evidence about the potential health effects of waterpipe tobacco smoking.

Correlates of e-cigarette use before and after comprehensive regulatory changes and e-liquid flavour ban among general population

INTRODUCTION

In 2016, the Finnish Tobacco Act was revised to harmonise e-cigarette regulations with the EU Tobacco Products Directive. Unlike before, the sale of nicotine-containing e-liquids was allowed while additional national regulations included, for example, a ban for other than unflavoured and tobacco-flavoured e-liquids. This study examines the correlates of e-cigarette use before and after the comprehensive regulatory change, and characteristics and correlates of flavoured e-cigarette use after the flavour ban in the general Finnish population.

METHODS

Repeated cross-sectional population-based drug surveys for 15-69-year-olds in 2014 (n = 3485; 50% response rate) and in 2018 (n = 3229; 46%). Correlates of e-cigarette use were studied with logistic regression models.

RESULTS

Current e-cigarette use remained infrequent (approximately 2%) and the correlates of e-cigarette use varied only slightly between the study years. In 2018, of past-year e-cigarette users (n = 316), 43% used unflavoured e-liquids, 24% used tobacco and 43% used other flavours, fruits being the most common. In univariate models, demographic variables, smoking and e-cigarette use-related factors were associated with flavoured e-cigarette use. In multivariable models, those who used e-cigarettes to experiment used unflavoured e-cigarettes more likely than other than tobacco flavours (odds ratio 3.00, 95% confidence interval 1.15-7.82).

DISCUSSION AND CONCLUSIONS

In Finland, the regulated entry of nicotine-containing e-liquids to retail sales has not led to increased e-cigarette use in the general population. After the flavour ban, other than tobacco-flavoured e-cigarette use still occurs. The use of flavoured e-cigarettes is associated with reasons for e-cigarette use. Flavoured e-cigarette use and its correlates warrant further monitoring.

Menthol in Electronic Cigarettes Causes Biophysical Inhibition of Pulmonary Surfactant

With an increasing prevalence of electronic cigarette (e-cigarette) use, especially among youth, there is an urgent need to better understand the biological risks and pathophysiology of health conditions related to e-cigarettes. A majority of e-cigarette aerosols are in the submicron size and would deposit in the alveolar region of the lung, where they must first interact with the endogenous pulmonary surfactant. To date, little is known whether e-cigarette aerosols have an adverse impact on the pulmonary surfactant. We have systematically studied the effect of individual e-cigarette ingredients on an animal-derived clinical surfactant preparation, bovine lipid extract surfactant, using a combination of biophysical and analytical techniques, including in vitro biophysical simulations using constrained drop surfactometry, molecular imaging with atomic force microscopy, chemical assays using carbon nuclear magnetic resonance and circular dichroism, and in silico molecular dynamics simulations. All data collectively suggest that flavorings used in e-cigarettes, especially menthol, play a predominant role in inhibiting the biophysical function of the surfactant. The mechanism of biophysical inhibition appears to involve menthol interactions with both phospholipids and hydrophobic proteins of the natural surfactant. These results provide novel insights into the understanding of the health impact of e-cigarettes and may contribute to a better regulation of e-cigarette products.

Youth use of e-liquid flavours-a systematic review exploring patterns of use of e-liquid flavours and associations with continued vaping, tobacco smoking uptake or cessation

BACKGROUND AND AIMS

There is concern that young people may be attracted to e-liquid flavours, prompting long-term vaping in naive users and potentially subsequent tobacco smoking. We aimed to review the use of e-liquid flavours by young people and describe associations with uptake or cessation of both regular vaping and tobacco smoking, adverse effects and subjective experiences.

DESIGN

Systematic review, including interventional, observational and qualitative studies reporting on the use of e-cigarette flavours by young people (aged < 18 years).

SETTING

Studies published in English language from any country or cultural setting.

PARTICIPANTS

Young people and their carers (aged < 18 years).

MEASUREMENTS

A meta-analysis was not possible due to substantial heterogeneity, inconsistency in reporting of flavour categorizations and non-interventional study designs; thus, we narratively report findings.

FINDINGS

In total, 58 studies were included. The quality of the evidence was extremely low. Most (n = 39) studies were cross-sectional survey designs. In total, 11 longitudinal cohort studies assessed trajectories; eight qualitative studies reported on user experiences. Studies reported views and experiences of a total of 512 874 young people. Both cross-sectional and longitudinal studies suggested that flavours are important for initiation and continuation of vaping. Qualitative evidence shows interest and enjoyment in flavours. There was judged to be insufficient evidence that use of e-liquid flavours specifically is associated with uptake of smoking. No studies found clear associations between flavours and cessation in this population. We found no included reports of adverse effects of flavours.

CONCLUSIONS

Flavours may be an important motivator for e-cigarette uptake, but the role of flavours in tobacco smoking uptake or cessation is unclear. The quality of the evidence on use of e-cigarette flavours by young people is low overall.

Agreement Between Self-reports and Photos to Assess e-Cigarette Device and Liquid Characteristics in Wave 1 of the Vaping and Patterns of e-Cigarette Use Research Study: Web-Based Longitudinal Cohort Study

Background

e-Cigarette device and liquid characteristics are highly customizable; these characteristics impact nicotine delivery and exposure to toxic constituents. It is critical to understand optimal methods for measuring these characteristics to accurately assess their impacts on user behavior and health.

Objective

To inform future survey development, we assessed the agreement between responses from survey participants (self-reports) and photos uploaded by participants and the quantity of usable data derived from each approach.

Methods

Adult regular e-cigarette users (≥5 days per week) aged ≥21 years (N=1209) were asked questions about and submitted photos of their most used e-cigarette device (1209/1209, 100%) and liquid (1132/1209, 93.63%). Device variables assessed included brand, model, reusability, refillability, display, and adjustable power. Liquid variables included brand, flavor, nicotine concentration, nicotine formulation, and bottle size. For each variable, percentage agreement was calculated where self-report and photo data were available. Krippendorff α and intraclass correlation coefficient (ICC) were calculated for categorical and continuous variables, respectively. Results were stratified by device (disposable, reusable with disposable pods or cartridges, and reusable with refillable pods, cartridges, or tanks) and liquid (customized and noncustomized) type. The sample size for each calculation ranged from 3.89% (47/1209; model of disposable devices) to 95.12% (1150/1209; device reusability).

Results

Percentage agreement between photos and self-reports was substantial to very high across device and liquid types for all variables except nicotine concentration. These results are consistent with Krippendorff α calculations, except where prevalence bias was suspected. ICC results for nicotine concentration and bottle size were lower than percentage agreement, likely because ICC accounts for the level of disagreement between values. Agreement varied by device and liquid type. For example, percentage agreement for device brand was higher among users of reusable devices (94%) than among users of disposable devices (75%). Low percentage agreement may result from poor participant knowledge of characteristics, user modifications of devices inconsistent with manufacturer-intended use, inaccurate or incomplete information on websites, or photo submissions that are not a participant’s most used device or liquid. The number of excluded values (eg, self-report was “don’t know” or no photo submitted) differed between self-reports and photos; for questions asked to participants, self-reports had more usable data than photos for all variables except device model and nicotine formulation.

Conclusions

Photos and self-reports yield data of similar accuracy for most variables assessed in this study: device brand, device model, reusability, adjustable power, display, refillability, liquid brand, flavor, and bottle size. Self-reports provided more data for all variables except device model and nicotine formulation. Using these approaches simultaneously may optimize data quantity and quality. Future research should examine how to assess nicotine concentration and variables not included in this study (eg, wattage and resistance) and the resource requirements of these approaches.

Influence of E-Liquid Humectants, Nicotine, and Flavorings on Aerosol Particle Size Distribution and Implications for Modeling Respiratory Deposition

Electronic cigarette, or vaping, products are used to heat an e-liquid to form an aerosol (liquid droplets suspended in gas) that the user inhales; a portion of this aerosol deposits in their respiratory tract and the remainder is exhaled, thereby potentially creating opportunity for secondhand exposure to bystanders (e.g., in homes, automobiles, and workplaces). Particle size, a critical factor in respiratory deposition (and therefore potential for secondhand exposure), could be influenced by e-liquid composition. Hence, the purposes of this study were to (1) test the influence of laboratory-prepared e-liquid composition [ratio of propylene glycol (PG) to vegetable glycerin (VG) humectants, nicotine, and flavorings] on particle size distribution and (2) model respiratory dosimetry. All e-liquids were aerosolized using a second-generation reference e-cigarette. We measured particle size distribution based on mass using a low-flow cascade impactor (LFCI) and size distribution based on number using real-time mobility sizers. Mass median aerodynamic diameters (MMADs) of aerosol from e-liquids that contained only humectants were significantly larger compared with e-liquids that contained flavorings or nicotine (p = 0.005). Humectant ratio significantly influenced MMADs; all aerosols from e-liquids prepared with 70:30 PG:VG were significantly larger compared with e-liquids prepared with 30:70 PG:VG (p = 0.017). In contrast to the LFCI approach, the high dilution and sampling flow rate of a fast mobility particle sizer strongly influenced particle size measurements (i.e., all calculated MMAD values were &lt; 75 nm). Dosimetry modeling using LFCI data indicated that a portion of inhaled particles will deposit throughout the respiratory tract, though statistical differences in aerosol MMADs among e-liquid formulations did not translate into large differences in deposition estimates. A portion of inhaled aerosol will be exhaled and could be a source for secondhand exposure. Use of laboratory-prepared e-liquids and a reference e-cigarette to standardize aerosol generation and a LFCI to measure particle size distribution without dilution represents an improved method to characterize physical properties of volatile aerosol particles and permitted determination of MMAD values more representative of e-cigarette aerosol in situ, which in turn, can help to improve dose modeling for users and bystanders.

Preferred flavors and tobacco use patterns in adult dual users of cigarettes and ENDS

OBJECTIVES

This study examined how adult dual users of cigarettes and electronic nicotine delivery system (ENDS) flavor preference varied by demographics, tobacco history, motives, and expectancies for ENDS, and how ENDS flavor preference was associated with changes in cigarette and ENDS use over 12 months.

METHODS

Data come from the baseline and 12-month waves of an observational study of adult dual cigarette and ENDS users (N = 406). Flavor preferences were grouped into 4 categories: tobacco (12.6%), menthol/mint (34.7%), sweet (44.8%), and other (7.9%).

RESULTS

Users of sweet-flavored ENDS were significantly younger than those who used tobacco- or menthol flavors. Black dual users were significantly more likely than other racial groups to use menthol and less likely to use sweet flavors. Dual users who preferred sweet flavors smoked cigarettes on fewer days than those who preferred tobacco and menthol flavors, were less cigarette dependent, more strongly endorsed boredom reduction expectancies and motives related to taste and sensory experience and were more likely to stop smoking by 12 months.

CONCLUSIONS

Dual users of cigarettes and ENDS who preferred sweet flavored ENDS differed in demographics, tobacco history, motives, expectancies, and smoking changes. Findings have implications for interventions and regulations.

The effect of emerging tobacco related products and their toxic constituents on thrombosis

Although conventional cigarette smoking is declining, emerging tobacco related products (ETRPs) are currently gaining ground, especially among the youth. These products include electronic cigarettes, waterpipes/hookah, cigars/cigarillo, smokeless tobacco, and heat-not-burn cigarettes. The observed increase in the use of ETRPs is multifactorial and complex but appears to be mainly driven by efforts from the major tobacco companies to reinvent themselves, and present more appealing and allegedly safe(r) tobacco products. However, it is becoming apparent that these products produce substantial amounts of toxic chemicals, many of which have been shown to exert negative health effects, including in the context of the cardiovascular system. Thus, there has been research efforts, albeit limited in general, to characterize the health impact of these products on occlusive/thrombotic cardiovascular diseases (CVD). In this review, we will discuss the potential impact of ETRPs on thrombosis-based CVD. Specifically, we will review how these products and the major chemicals they produce and/or emit can trigger key players in the process of thrombosis, namely inflammation, oxidative stress, platelets, coagulation, and the vascular endothelium, and the relationship between these effects.

Nicotine content, labelling and flavours of e-liquids in Canada in 2020: a scan of the online retail market

INTRODUCTION

The e-cigarette market in Canada has rapidly evolved following the implementation of the Tobacco and Vaping Products Act in May 2018, which liberalized the promotion and sale of vaping products. To date, there is little data on the market profile of key product attributes, including nicotine content, labelling practices and flavours.

METHODS

An online scan of vaping product retailers (manufacturer, two national, five provincial) was conducted in 2020 to assess the e-liquids available on the Canadian market. Data were extracted from websites and product images regarding the nicotine content, labelling and flavours of e-liquids.

RESULTS

We identified 1746 e-liquids, with a total of 4790 different nicotine concentrations. Approximately half of the e-liquids were offered with salt-base nicotine (46.6%) and half with freebase nicotine (53.2%); the remainder were hybrids (0.2%). The mean nicotine concentration of salt-base e-liquids (3.4%) was higher than freebase e-liquids (0.5%) (p < 0.001). Labels indicating the presence of nicotine were visible on twothirds of e-liquid packaging displayed online (63.2%) while three-quarters of packaging displayed the nicotine concentration (73.7%), and more than half of packaging displayed health warnings (58.9%). A variety of flavours were also identified, with fruit being the most common (43.6%), followed by candy/desserts (27.6%) and non-alcoholic drinks (12.5%).

CONCLUSION

Findings demonstrate the diversity of the online e-cigarette market in Canada, including the availability of higher-concentration salt-base nicotine products. Flavour restrictions have the potential to dramatically reduce the number of e-liquid flavours on the market, while restricting nicotine concentrations to < 20 mg/mL will predominantly restrict salt-based e-liquids.

Do e-cigarettes attract youths who are otherwise unlikely to use addictive substances? Cross-sectional analyses of Dutch and Flemish secondary school students

INTRODUCTION

E-cigarettes are popular among youth. There are concerns that e-cigarettes attract youth that would otherwise not use addictive substances. While e-cigarettes are thought to be less harmful than tobacco, there is reason for caution. We examined to what extent adolescent e-cigarette users have characteristics associated with increased risk of substance use.

METHODS

We collected cross-sectional survey data in 2018 among 10 schools throughout the Netherlands and Belgium (N=2794; age 10-18 years). We examined differences in characteristics and behaviors between e-cigarette ever users and never users, and former users and current users. We also explored differences in use of flavors and use of nicotine.

RESULTS

Compared to never-users, e-cigarettes users more often were boys, older, had lower education level, non-Dutch or non-Belgian ethnicity, reported more combustible tobacco use, more smoking family members or family with problematic substance use, more smoking friends, more depressive symptoms, more impulsivity, more delinquent behavior, were more susceptible to smoking, had more positive smoking expectancies, and more ever use of substances. Users of non-tobacco flavored e-cigarettes and e-cigarettes without nicotine had fewer characteristics known to be related to an increased risk of substance use, compared to users of tobacco-flavored e-cigarettes and e-cigarettes with nicotine.

CONCLUSIONS

Adolescent e-cigarette users are more like youths who experiment with addictive substances compared to non-users. Thus, e-cigarettes users were more likely to use substances, regardless of whether they used e-cigarettes first. This may not be true for all types of e-cigarettes, as users of e-cigarettes without nicotine or with non-tobacco flavors were less like youths who experiment with substances.

Vitamin E Acetate Determination in Vaping Liquids and Non-targeted Analysis of Vaping Emissions of Diluents of Concern, Vitamin E Acetate and Medium-Chain Triglycerides Oil

During the summer of 2019, cases of lung injury associated with vaping emerged in North America, including among individuals who reported exclusive use of nicotine vaping liquids. Once vitamin E acetate was identified as a potential causative agent a quantitative method based on a simple sample dilution, separation by gas chromatography and analysis by triple quadrupole mass spectrometry (GC MSMS) was developed. Method detection limit (MDL) and limit of quantification (LOQ) were determined at 0.159 µg/mL and 0.505 µg/mL, respectively. The analysis was performed on a subset of 203 commercially sourced nicotine containing vaping liquids of various flavour profile and nicotine range (nicotine free-59 mg/mL) from an internal inventory. The target analyte, Vitamin E Acetate, was not detected in any samples analyzed, as expected, given the reported detection in literature and high association of the chemical with cannabis and not nicotine containing vaping products.

New Analytical Method for Quantifying Flavoring Chemicals of Potential Respiratory Health Risk Concerns in e-Cigarette Liquids

Numerous flavoring chemicals are added to e-cigarette liquids to create various flavors. Flavorings provide sensory experience to users and increase product appeal; however, concerns have been raised about their potential inhalation toxicity. Estimating potential health risk of inhaling these chemicals has been challenging since little is known about their actual concentrations in e-cigarette products. To date, a limited number of analytical methods exist to measure the concentrations of flavoring chemicals in e-cigarette products. We have developed an analytical method that accurately and precisely measures the concentrations of 20 flavoring chemicals of potential inhalation risk concerns: 2,3,5-trimethylpyrazine, acetoin, benzaldehyde, benzyl alcohol, butanoic acid, dl-limonene, ethyl maltol, ethyl salicylate, ethyl vanillin, eucalyptol, eugenol, furaneol, isovanillin, l-menthol, maltol, methyl salicylate, pulegone, trans-cinnamaldehyde, triacetin, and vanillin. Calibration and QC solutions were prepared in 50:50 propylene glycol (PG):vegetable glycerin (VG) and 5% H₂O and flavoring concentrations ranging from 0.02 to 10.00 mg/ml. Samples of commercial e-cigarette liquids, calibration and QC solutions were combined with 30 µL of an internal standard mix (benzene-d6, pyridine-d5, chlorobenzene-d5, naphthalene-d8 and acenaphthene-d10; 1 mg/ml each) and were diluted 100-fold into methanol. Analysis was performed on an Agilent 7890B/7250 GC/Q-TOF using a DB-624UI column (30 m x 0.25 mmID x 1.4 μm film thickness), with a total runtime of 13.5 min. Calibration curves were fit using a weighted quadratic model and correlations of determination (r²) values exceeded 0.990 for all chemicals. Bias and precision tests yielded values less than 20% and lower limits of quantitation (LLOQ) ranged from 0.02 to 0.63 mg/ml. Over 200 commercially available products, purchased or collected from adult e-cigarette users and spanning a range of flavor categories, were evaluated with this method. Concentrations of pulegone, a suspected carcinogen, varied from below limit of quantitation (BLOQ) to 0.32 mg/ml, while acetoin and vanillin, known precursors to more cytotoxic byproducts, ranged from BLOQ to 1.52 mg/ml and from BLOQ to 16.22 mg/ml, respectively. This method features a wide dynamic working range and allows for a rapid routine analysis of flavoring additives in commercial e-cigarette liquids.

Open Characterization of Vaping Liquids in Canada: Chemical Profiles and Trends

Currently, there is a lack of comprehensive data on the diversity of chemicals present in vaping liquids. To address this gap, a non-targeted analysis of 825 vaping liquids collected between 2017 and 2019 from Canadian retailers was conducted. Prior to mass spectrometry analysis, samples were diluted 1:500 v/v with methanol or acetonitrile. Chemical compound separation and analysis was carried out using gas chromatography and triple quadrupole mass spectrometry (GC-MS/MS) systems operated in the full scan mode and mass range of 35-450 m/z. Mass spectrum for each sample was obtained in electron ionization at 70 eV and processed. Non-targeted identification workflow included use of automated mass spectral deconvolution and identification system (AMDIS), where required, as well as a number of commercially available spectral libraries. In order to validate identities, an in-house database of expected compounds previously detected in vaping liquids was used along with genuine analytical standards for compounds of interest. This resulted in a dataset of over 1,500 unique detected chemicals. Approximately half of these chemical compounds were detected only once in a single product and not in multiple products analyzed. For any sample analyzed, on average, 40% of the chemical constituents appeared to have flavouring properties. The remainder were nicotine and related alkaloids, processing, degradation or indirect additives, natural extractives and compounds with unknown roles. Data published here from the project on the Open Characterization of vaping liquids is unique as it offers a detailed understanding of products' flavour chemical profiles, the presence and frequency of chemicals of potential health concern, as well as trends and changes in products' chemical complexity over a three-year period. Non-targeted chemical surveillance such as this present valuable tools to public health officials and researchers in responding to emergent issues such as vaping associated lung injury or informing chemical based strategies which may be aimed at addressing product safety or appeal.