Menthol and Other Flavor Chemicals in Cigarettes from Vietnam and the Philippines.

INTRODUCTION: Tobacco product flavors can increase product appeal, adolescent initiation and experimentation, and difficulty quitting. Flavored tobacco products are not restricted in Vietnam or the Philippines despite the high smoking prevalence among those 15 years of age and older (24% and 23%, respectively). There are no published reports to our knowledge on the levels of flavor chemicals in the cigarettes sold in these two countries. METHODS: Cigarettes were purchased in Vietnam (32 brand variants) and the Philippines (19 brand variants) during 2020. Chemical analyses gave the mg/filter, mg/rod, and mg/stick (= mg/(filter + rod)) values for 180 individual flavor chemicals. Values were calculated for menthol, clove-related compounds, and "other flavor chemicals" (OFCs). RESULTS: Five flavor groupings were found among the brand variants purchased in Vietnam: menthol + OFCs (n = 15), OFCs only (n = 8), nonflavored (n = 7), menthol + OFCs with a clove flavorant (n = 1) and menthol only (n = 1). Three flavor groupings were found among the brand variants purchased in the Philippines: menthol + OFCs (n = 10), nonflavored (n = 5), and menthol only (n = 4). CONCLUSIONS: A range of flavored cigarette products are being offered by tobacco companies in Vietnam and the Philippines, presumably to maximize cigarette sales. Regulation of flavor chemicals should be considered in these two countries. IMPLICATIONS: Article 9 of the WHO Framework Convention on Tobacco Control (FCTC), ratified by both Vietnam and the Philippines, states that "there is no justification for permitting the use of ingredients, such as flavoring agents, which help make tobacco products attractive." Flavors increase product appeal, adolescent initiation and experimentation, and difficulty quitting. These analyses found that cigarettes purchased in Vietnam and the Philippines contained menthol and other flavor chemicals. Tobacco companies are offering multiple flavor chemical profiles and nominally nonflavored versions in these countries; regulation of flavor chemicals should be considered in these two countries.

Effects of E-Cigarette Flavor Enhancing Capsules on Inhalable Aerosols.

The flavor of inhaled e-cigarette aerosols may be augmented using crushable flavor capsules added to e-cigarettes. For example, Puff Krush contains breakable flavor capsules in a sorbent material. The capsules are crushed, and then, aerosol passes through the saturated sorbent material before inhalation. Herein, we used NMR and GC-MS to identify the capsule medium chain triglyceride (MCT) solvent and flavorants in selected Puff Krush flavor capsules and then determined which molecules from the capsule transfer into aerosols. MCTs from the Puff Krush were not found in the aerosols, and ∼50% of Puff Krush flavorants transferred into the aerosol upon vaping.

Exposure, Retention, Exhalation, Symptoms, and Environmental Accumulation of Chemicals During JUUL Vaping.

Little is known about the chemical exposures that electronic cigarette (EC) users receive and emit during JUUL vaping and if exposures produce symptoms dose dependently. This study examined chemical exposure (dose), retention, symptoms during vaping, and the environmental accumulation of exhaled propylene glycol (PG), glycerol (G), nicotine, and menthol in a cohort of human participants who vaped JUUL "Menthol" ECs. We refer to this environmental accumulation as "EC exhaled aerosol residue" (ECEAR). Chemicals were quantified using gas chromatography/mass spectrometry in JUUL pods before and after use, lab-generated aerosols, human exhaled aerosols, and in ECEAR. Unvaped JUUL "Menthol" pods contained ∼621.3 mg/mL of G, ∼264.9 mg/mL of PG, ∼59.3 mg/mL of nicotine, ∼13.3 mg/mL of menthol, and ∼0.1 mg/mL of the coolant WS-23. Eleven experienced male EC users (aged 21-26) provided exhaled aerosol and residue samples before and after vaping JUUL pods. Participants vaped ad libitum for 20 min, while their average puff count (22 ± 6.4) and puff duration (4.4 ± 2.0) were recorded. The transfer efficiency of nicotine, menthol, and WS-23 from the pod fluid into the aerosol varied with each chemical and was generally similar across flow rates (9-47 mL/s). At 21 mL/s, the average mass of each chemical retained by the participants who vaped 20 min was 53.2 ± 40.3 mg for G, 18.9 ± 14.3 mg for PG, 3.3 ± 2.7 mg for nicotine, and 0.5 ± 0.4 mg for menthol, with retention deduced to be ∼90-100% for each chemical. There was a significant positive relationship between the number of symptoms during vaping and total chemical mass retained. ECEAR accumulated on enclosed surfaces where it could contribute to passive exposure. These data will be valuable to researchers studying human exposure to EC aerosols and agencies that regulate EC products.

Eugenol, menthol and other flavour chemicals in kreteks and 'white' cigarettes purchased in Indonesia.

BACKGROUND: Flavoured tobacco products are not restricted in Indonesia, a country with about 68 million adults who smoke. Most use clove-mixed tobacco cigarettes ('kreteks'); non-clove ('white') cigarettes are also available. Although the use of flavour chemicals has been identified by WHO as promoting tobacco use, little has been reported for Indonesia about the levels of flavourants in either kreteks or 'white cigarettes'. METHODS: 22 kretek brand variants and nine 'white' cigarette brand variants were purchased in Indonesia during 2021/2022; one of the kretek packs contained three colour-coded variants, giving a total sample number of 24 for the kreteks. Chemical analyses gave the mg/stick (=mg/(filter+rod)) values for 180 individual flavour chemicals that included eugenol (a clove-flavoured compound), four other clove-related compounds and menthol. RESULTS: Eugenol was present at significant levels in all 24 kreteks (2.8-33.8 mg/stick), but was essentially absent in all of the cigarettes. Menthol was present in 14 of 24 kreteks, with levels ranging from 2.8 to 12.9 mg/stick, and in five of the nine cigarettes, with levels ranging from 3.6 to 10.8 mg/stick. Other flavour chemicals were also found in many of the kretek and cigarette samples. CONCLUSIONS: In this small sample, we found numerous variations of flavoured tobacco products offered by multinational and national companies in Indonesia. Given the body of evidence that flavours make tobacco products more appealing, regulation of clove-related compounds, menthol and other flavour chemicals should be considered in Indonesia.

Disposable Puff Bar Electronic Cigarettes: Chemical Composition and Toxicity of E-liquids and a Synthetic Coolant.

The popularity of disposable fourth-generation electronic cigarettes (ECs) among young adults and adolescents has been increasing since the ban on flavored cartridge EC products such as JUUL. Although the constituents and toxicity of some cartridge-based fourth-generation ECs, such as JUUL, have been studied, limited data exist for other disposable ECs such as Puff. The purpose of this study was to determine flavor chemicals, synthetic coolants, and nicotine concentrations in 16 disposable Puff devices, evaluate the cytotoxicity of the different flavors from the Puff brand using in vitro assays, and investigate the health risks of synthetic coolants in EC products. Gas chromatography/mass spectrometry was used to identify and quantify chemicals in Puff EC fluids. One hundred and twenty-six flavor chemicals were identified in Puff fluids, and 16 were >1 mg/mL. WS-23 (2-isopropyl-N,2,3-trimethylbutyramide) was present in all products, and concentrations ranged from 0.8 to 45.1 mg/mL. WS-3 (N-ethyl-p-menthane-3-carboxamide) concentrations ranged from 1.5 to 16.4 mg/mL in 6/16 products. Nicotine concentrations ranged from 40.6 to 52.4 (average 44.8 mg/mL). All unvaped fluids were cytotoxic at dilutions between 0.1 and 10% in the MTT and neutral red uptake assays when tested with BEAS-2B lung epithelial cells. The cytotoxicity of Puff fluids was highly correlated with total chemical concentrations, nicotine, WS-23, both synthetic coolants, and synthetic coolants plus ethyl maltol. Lower concentrations of WS-23 than those in the fluids adversely affected cell growth and morphology. Concentrations of synthetic coolants exceeded levels used in consumer products. The margin of exposure data showed that WS-3 and WS-23 concentrations were high enough in Puff products to present a health hazard. Our study demonstrates that disposable Puff ECs have high levels of cytotoxic chemicals. The data support the regulation of flavor chemicals and synthetic coolants in ECs to limit potentially harmful health effects.

Flavour chemicals, synthetic coolants and pulegone in popular mint-flavoured and menthol-flavoured e-cigarettes.

BACKGROUND: The Food and Drug Administration (FDA) has recently banned flavours from pod-style electronic cigarettes (e-cigarettes), except for menthol and tobacco. JUUL customers have quickly discovered that flavoured disposable e-cigarettes from other manufacturers, such as Puff, are readily available. Our goal was to compare flavour chemicals, synthetic coolants and pulegone in mint-flavoured/menthol-flavoured e-cigarettes from JUUL and Puff, evaluate the cytotoxicity of the coolants and perform a cancer risk assessment for pulegone, which is present in both JUUL pods and disposable Puff products. METHODS: Identification and quantification of chemicals were performed using gas chromatography/mass spectrometry. Cytotoxicity of the coolants was evaluated with BEAS-2B cells using the MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cancer risk of pulegone was calculated using the margin of exposure (MOE). RESULTS: Menthol was the dominant flavour chemical (>1 mg/mL) in all products from both manufacturers. Minor flavour chemicals (<1 mg/mL) differed in the JUUL and Puff fluids and may produce flavour accents. The concentrations of WS-3 and WS-23 were higher in Puff than in JUUL. WS-23 was cytotoxic in the MTT assay at concentrations 90 times lower than concentrations in Puff fluids. The risk of cancer (MOE<10 000) was greater for mint than for menthol products and greater for Puff than for JUUL. CONCLUSIONS: Switching from flavoured JUUL to Puff e-cigarettes may expose users to increased harm due to the higher levels of WS-23 and pulegone in Puff products. Cancer risk may be reduced in e-cigarettes by using pure menthol rather than mint oils to produce minty-flavoured e-cigarette products.

Ethyl maltol, vanillin, corylone and other conventional confectionery-related flavour chemicals dominate in some e-cigarette liquids labelled 'tobacco' flavoured.

BACKGROUND: The increased popularity of electronic cigarettes (e-cigarettes) has been linked to the abundance of flavoured products that are attractive to adolescents and young adults. In the last decade, e-cigarette designs have evolved through four generations that include modifications in battery power, e-cigarette liquid (e-liquid) reservoirs and atomiser units. E-liquids have likewise evolved in terms of solvent use/ratios, concentration and number of flavour chemicals, use of nicotine salts and acids, the recent increased use of synthetic cooling agents and the introduction of synthetic nicotine. Our current objective was to evaluate and compare the evolving composition of tobacco-flavoured e-liquids over the last 10 years. METHODS: Our extensive database of flavour chemicals in e-liquids was used to identify trends and changes in flavour chemical composition and concentrations. RESULTS: Tobacco-flavoured products purchased in 2010 and 2011 generally had very few flavour chemicals, and their concentrations were generally very low. In tobacco-flavoured refill fluids purchased in 2019 and Puff Bar Tobacco e-cigarettes, the total number and concentration of flavour chemicals were higher than expected. Products with total flavour chemicals >10 mg/mL contained one to five dominant flavour chemicals (>1 mg/mL). The most frequently used flavour chemicals in tobacco e-liquids were fruity and caramellic. CONCLUSIONS: There is a need for continuous surveillance of e-liquids, which are evolving in often subtle and harmful ways. Chemical constituents of tobacco flavours should be monitored as they clearly can be doctored by manufacturers to have a taste that would appeal to young users.

'Menthol-Plus': a major category of cigarette found among 'concept' descriptor cigarettes from Mexico.

BACKGROUND: Tobacco companies are offering cigarettes with 'concept' descriptor names that suggest sensation and/or flavour properties (eg, Marlboro 'Velvet Fusion'). Little has been known about the identities and levels of flavour chemicals in such cigarettes. METHODS: Thirty-three filter cigarette variants from 27 packs (including two sampler packs with four variations each) from Canada and Mexico were analysed (rod + filter) for 177 flavour chemicals plus triacetin, a filter plasticiser and possible flavourant. Five brands of US mentholated filter cigarettes were also analysed. RESULTS: Twenty-seven of the 33 cigarettes (all were Mexican variants) were categorised as 'menthol-plus': significant menthol (3.0-11.9 mg/cigarette), plus varying amounts (0.32-3.4 mg/cigarette) of total other flavour chemicals (TOFCs) (excludes triacetin). For 10 of the 27, TOFCs >1.0 mg/cigarette. For 7 of the 27, the TOFCs profile was categorised as containing total fruit flavour compounds (TFFCs) >1.0 mg/cigarette. One Mexican variant was categorised as 'menthol-only' (TOFCs ≤0.15 mg/cigarette). All menthol-plus and menthol-only cigarettes contained one or two optional-crush capsules in their filters (crushed prior to analysis). All five Canadian brand variants were 'non-flavoured'. All five US brand variants were 'menthol-only'. CONCLUSIONS: All but one of the 'concept' descriptor cigarettes from Mexico were 'menthol-plus'. While the Canadian cigarettes complied with Canada's flavour chemical ban, concept descriptors on the packs may increase appeal. Given the scale of the problem posed by menthol alone, health officials seeking to decrease the appeal of smoked tobacco should examine the extent to which 'concept descriptor' cigarettes using 'menthol-plus' flavour profiling together with artful descriptors are furthering the problem of smoked tobacco.

Determination of (R)-(+)- and (S)-(-)-Nicotine Chirality in Puff Bar E-Liquids by 1H NMR Spectroscopy, Polarimetry, and Gas Chromatography-Mass Spectrometry.

Tobacco products generally contain tobacco-derived nicotine (TDN; having ∼99+% (S)-(-)-nicotine). Recent United States regulation has led some producers to transition to synthetic ("tobacco-free") nicotine. For example, Puff Bar is now marketed with tobacco-free nicotine (TFN; presumed to be racemic). To evaluate the claim that these new products contain TFN, we evaluated the presence of the two nicotine optical isomers by 1H NMR spectroscopy, polarimetry, and gas chromatography-mass spectrometry. Older Puff Bars were found to contain (S)-(-)-nicotine, and newer "TFN" Puff Bars were found to contain both (R)-(+) and (S)-(-) isomers-indicating TFN, albeit with slightly more of the (S)-(-)-nicotine form.

Measurement of the Free-Base Nicotine Fraction (αfb) in Electronic Cigarette Liquids by Headspace Solid-Phase Microextraction.

A method for determining the fraction of free-base nicotine (αfb) in electronic cigarette liquids ("e-liquids") based on headspace solid-phase microextraction (h-SPME) is described. The free-base concentration ce,fb = αfbce,T, where ce,T is the total (free-base + protonated) nicotine in the liquid. For gas/liquid equilibrium of the volatile free-base form, the headspace nicotine concentration is proportional to ce,fb and thus also to αfb. Headspace nicotine is proportionally absorbed with an SPME fiber. The fiber is thermally desorbed in the heated inlet of a gas chromatograph coupled to a mass spectrometer: the desorbed nicotine is measured by gas chromatography-mass spectrometry. For a second h-SPME measurement, an adequate base is added to the sample vial to convert essentially all protonated nicotine to the free-base form (αfb → 1.0). The ratio of the first h-SPME measurement to the second h-SPME measurement gives αfb in the initial sample. Using gaseous ammonia as the added base, the method was (1) verified using lab-prepared e-liquid solutions with known αfb values and (2) used to determine the αfb values for 18 commercial e-liquids. The measured αfb values ranged from 0.0 to 1.0. Increasing measurement error with decreasing αfb caused modestly lower method precision at small αfb. Adding a liquid organic base may be more convenient than adding gaseous ammonia: one of the samples was examined using triethylamine as the added base; the measurements agreed well (with ammonia, 0.27 ± 0.01; with triethylamine, 0.26 ± 0.04). Other workers have proposed examining the nicotine protonation state in e-liquids using three steps: (1) 1:10 dilution with CO2-free water; (2) measurement of pH; and (3) calculation of the resulting values for αfb,w,1:10, the free-base fraction in the diluted mostly aqueous phase. As expected and verified here, because of the generally greater abilities of organic acids to protonate nicotine in water versus in an e-liquid phase, αfb,w,1:10 values can be significantly less than actual e-liquid αfb values when αfb is not close to either 0 or 1.

Menthol in electronic cigarettes: A contributor to respiratory disease?

Menthol is widely used in tobacco products. This study compared the effects of menthol on human bronchial epithelium using submerged cultures, a VITROCELL® cloud chamber that provides air liquid interface (ALI) exposure without solvents or heating, and a Cultex ALI system that delivers aerosol equivalent to that inhaled during vaping. In submerged culture, menthol significantly increased calcium influx and mitochondrial reactive oxygen species (ROS) via the TRPM8 receptor, responses that were inhibited by a TRPM8 antagonist. VITROCELL® cloud chamber exposure of BEAS-2B monolayers increased mitochondrial protein oxidation, expression of the antioxidant enzyme SOD2, activation of NF-κB, and secretion of inflammatory cytokines (IL-6 and IL-8). Proteomics data collected following ALI exposure of 3D EpiAirway tissue in the Cultex showed upregulation of NRF-2-mediated oxidative stress, oxidative phosphorylation, and IL-8 signaling. Across the three platforms, menthol adversely effected human bronchial epithelium in a manner that could lead to respiratory disease.

Electronic Cigarette Refill Fluids Sold Worldwide: Flavor Chemical Composition, Toxicity, and Hazard Analysis.

Flavor chemicals in electronic cigarette (EC) fluids, which may negatively impact human health, have been studied in a limited number of countries/locations. To gain an understanding of how the composition and concentrations of flavor chemicals in ECs are influenced by product sale location, we evaluated refill fluids manufactured by one company (Ritchy LTD) and purchased worldwide. Flavor chemicals were identified and quantified using gas chromatography/mass spectrometry (GC/MS). We then screened the fluids for their effects on cytotoxicity (MTT assay) and proliferation (live-cell imaging) and tested authentic standards of specific flavor chemicals to identify those that were cytotoxic at concentrations found in refill fluids. A total of 126 flavor chemicals were detected in 103 bottles of refill fluid, and their number per/bottle ranged from 1-50 based on our target list. Two products had none of the flavor chemicals on our target list, nor did they have any nontargeted flavor chemicals. A total of 28 flavor chemicals were present at concentrations ≥1 mg/mL in at least one product, and 6 of these were present at concentrations ≥10 mg/mL. The total flavor chemical concentration was ≥1 mg/mL in 70% of the refill fluids and ≥10 mg/mL in 26%. For sub-brand duplicate bottles purchased in different countries, flavor chemical concentrations were similar and induced similar responses in the in vitro assays (cytotoxicity and cell growth inhibition). The levels of furaneol, benzyl alcohol, ethyl maltol, ethyl vanillin, corylone, and vanillin were significantly correlated with cytotoxicity. The margin of exposure calculations showed that pulegone and estragole levels were high enough in some products to present a nontrivial calculated risk for cancer. Flavor chemical concentrations in refill fluids often exceeded concentrations permitted in other consumer products. These data support the regulation of flavor chemicals in EC products to reduce their potential for producing both cancer and noncancer toxicological effects.

High-Nicotine Electronic Cigarette Products: Toxicity of JUUL Fluids and Aerosols Correlates Strongly with Nicotine and Some Flavor Chemical Concentrations.

Whereas JUUL electronic cigarettes (ECs) have captured the majority of the EC market, with a large fraction of their sales going to adolescents, little is known about their cytotoxicity and potential effects on health. The purpose of this study was to determine flavor chemical and nicotine concentrations in the eight currently marketed prefilled JUUL EC cartridges ("pods") and to evaluate the cytotoxicity of the different variants (e.g., "Cool Mint" and "Crème Brulee") using in vitro assays. Nicotine and flavor chemicals were analyzed using gas chromatography-mass spectrometry in pod fluid before and after vaping and in the corresponding aerosols. 59 flavor chemicals were identified in JUUL pod fluids, and 3 were >1 mg/mL. Duplicate pods were similar in flavor chemical composition and concentration. Nicotine concentrations (average 60.9 mg/mL) were significantly higher than those of any EC products we have previously analyzed. The transfer efficiency of individual flavor chemicals that were >1 mg/mL and nicotine from the pod fluid into aerosols was generally 35-80%. All pod fluids were cytotoxic at a 1:10 dilution (10%) in the MTT and neutral red uptake assays when tested with BEAS-2B lung epithelial cells. Most aerosols were cytotoxic in these assays at concentrations between 0.2 and 1.8%. The cytotoxicity of collected aerosol materials was highly correlated with nicotine and ethyl maltol concentrations and moderately to weakly correlated with total flavor chemical concentration and menthol concentration. Our study demonstrates that (1) some JUUL flavor pods have sufficiently high concentrations of flavor chemicals that may make them attractive to youth and (2) the concentrations of nicotine and some flavor chemicals (e.g., ethyl maltol) are high enough to be cytotoxic in acute in vitro assays, emphasizing the need to determine if JUUL products will lead to adverse health effects with chronic use.

Free-Base Nicotine Is Nearly Absent in Aerosol from IQOS Heat-Not-Burn Devices, As Determined by 1H NMR Spectroscopy.

Heat-not-burn products, eg, I quit ordinary smoking (IQOS), are becoming popular alternative tobacco products. The nicotine aerosol protonation state has addiction implications due to differences in absorption kinetics and harshness. Nicotine free-base fraction (αfb) ranges from 0 to 1. Herein, we report αfb for IQOS aerosols by exchange-averaged 1H NMR chemical shifts of the nicotine methyl protons in bulk aerosol and verified by headspace-solid phase microextraction-gas chromatography-mass spectrometry. The αfb ≈ 0 for products tested; likely a result of proton transfer from acetic acid and/or other additives in the largely aqueous aerosol. Others reported higher αfb for these products, however, their methods were subject to error due to solvent perturbation.

Gas/Particle Partitioning Constants of Nicotine, Selected Toxicants, and Flavor Chemicals in Solutions of 50/50 Propylene Glycol/Glycerol As Used in Electronic Cigarettes.

For an electronic cigarette (e-cigarette) aerosol with known total particulate matter concentration (TPM, µg/m3), predictions of the fractions of some compound i in the gas and particle phases ( fg, i and fp, i) at equilibrium can be made based on Kp, i (m3/µg), the compound-dependent gas/particle partitioning equilibrium constant. fg, i and fp, i affect the modes and locations of deposition in the respiratory tract. Kp, i depends inversely on (1) the pure compound liquid vapor pressure ( pL, io), (2) mole fraction activity coefficient (ζ i) in the absorbing liquid, and (3) mean molecular weight of the absorbing liquid (MW). Kp, i values were measured at 20 °C for 32 compounds as spiked into simulated e-cigarette liquids prepared as 50/50 mixtures (by weight) of propylene glycol (PG) and glycerol (GL). Kp, i values at 37 °C were estimated. The 32 compounds were nicotine (in free-base form), seven toxicants (propanal, acetone, hydroxyacetone, benzene, toluene, p-xylene, and ethylbenzene), and 24 flavor chemicals (2,3-pentanedione ("acetyl propionyl"), isobutyl acetate, ethyl butyrate, butyl butyrate, isoamyl acetate, 2,3-dimethylpyrazine, 3-methyl-1-butanol, limonene, 2,3,5-trimethylpyrazine, p-cymene, benzaldehyde, ( Z)-3-hexen-1-ol, menthol, 2-acetylpyrrole, benzyl alcohol, methyl salicylate, cinnamaldehyde, methyl anthranilate, (+)-aromadendrene, cinnamyl alcohol, methyl cinnamate, maltol, ethyl maltol, and coumarin). The measured log Kp, i values were found to be generally correlated with literature values of log pL, io; the scatter is caused by variation in ζ i between ∼1 and ∼1000. Kp measurements were attempted, but values were not reported for acetaldehyde, 2,3-butanedione (diacetyl), vanillin, and ethyl vanillin. Acetaldehyde was found to form significant amounts of its cyclic trimer and cyclic tetramer; for diacetyl, the evidence suggested significant amounts of reaction products, possibly hemiketals and ketals with PG/GL, and for vanillin and ethyl vanillin, the Kp values are large and accordingly more difficult to measure. fg values are calculated using a range of Kp and TPM values.

Flavour chemicals in a sample of non-cigarette tobacco products without explicit flavour names sold in New York City in 2015.

BACKGROUND: Youth who experiment with tobacco often start with flavoured products. In New York City (NYC), local law restricts sales of all tobacco products with 'characterising flavours' except for 'tobacco, menthol, mint and wintergreen'. Enforcement is based on packaging: explicit use of a flavour name (eg, 'strawberry') or image depicting a flavour (eg, a fruit) is presumptive evidence that a product is flavoured and therefore prohibited. However, a tobacco product may contain significant levels of added flavour chemicals even when the label does not explicitly use a flavour name. METHODS: Sixteen tobacco products were purchased within NYC in 2015 that did not have explicit flavour names, along with three with flavour names. These were analysed for 92 known flavour chemicals plus triacetin by gas chromatography/mass spectrometry. RESULTS: 14 of the 16 products had total determined flavour chemical levels that were higher (>0.3 mg/g) than in previously studied flavour-labelled products and of a chemical profile indicating added flavour chemicals. CONCLUSIONS: The results suggest that the tobacco industry has responded to sales restrictions by renaming flavoured products to avoid explicitly identifying them as flavoured. While chemical analysis is the most precise means of identifying flavours in tobacco products, federal tobacco laws pre-empt localities from basing regulations on that approach, limiting enforcement options. If the Food and Drug Administration would mandate that all tobacco products must indicate when flavourings are present above a specific level, local jurisdictions could enforce their sales restrictions. A level of 0.1 mg/g for total added flavour chemicals is suggested here as a relevant reference value for regulating added flavour chemicals in tobacco products.

Breath Biomarkers to Measure Uptake of Volatile Organic Compounds by Bicyclists.

Breath biomarkers were used to study uptake of traffic-related volatile organic compounds (VOCs) from urban bicycling. Breath analysis was selected because it is one of the least invasive methods to assess urban traveler exposure. Research hurdles that were overcome included considering that factors other than on-road exposure can influence concentrations in the body, and absorbed doses during a trip can be small compared to baseline body burdens. Pre-trip, on-road, and post-trip breath concentrations and ambient air concentrations were determined for 26 VOCs for bicyclists traveling on different path types. Statistical analyses of the concentration data identified eight monoaromatic hydrocarbons potentially useful as breath biomarkers to compare differences in body levels brought about by urban travel choices. Breath concentrations of the biomarker compounds were significantly higher than background levels after riding on high-traffic arterial streets and on a path through a high-exposure industrial area, but not after riding on low-traffic local streets or on other off-street paths. Modeled effects of high-traffic streets on ambient concentrations were 100-200% larger than those of low-traffic streets; modeled effects of high-traffic streets on breath concentrations were 40-100% larger than those of low-traffic streets. Similar percentage increases in breath concentrations are expected for bicyclists in other cities.

Flavour chemicals in electronic cigarette fluids.

BACKGROUND: Most e-cigarette liquids contain flavour chemicals. Flavour chemicals certified as safe for ingestion by the Flavor Extracts Manufacturers Association may not be safe for use in e-cigarettes. This study identified and measured flavour chemicals in 30 e-cigarette fluids. METHODS: Two brands of single-use e-cigarettes were selected and their fluids in multiple flavour types analysed by gas chromatography/mass spectrometry. For the same flavour types, and for selected confectionary flavours (eg, bubble gum and cotton candy), also analysed were convenience samples of e-cigarette fluids in refill bottles from local 'vape' shops and online retailers. RESULTS: In many liquids, total flavour chemicals were found to be in the ∼1-4% range (10-40 mg/mL); labelled levels of nicotine were in the range of 0.6-2.4% (6 to 24 mg/mL). A significant number of the flavour chemicals were aldehydes, a compound class recognised as 'primary irritants' of mucosal tissue of the respiratory tract. Many of the products contained the same flavour chemicals: vanillin and/or ethyl vanillin was found in 17 of the liquids as one of the top three flavour chemicals, and/or at ≥0.5 mg/mL. CONCLUSIONS: The concentrations of some flavour chemicals in e-cigarette fluids are sufficiently high for inhalation exposure by vaping to be of toxicological concern. Regulatory limits should be contemplated for levels of some of the more worrisome chemicals as well as for total flavour chemical levels. Ingredient labeling should also be required.

Distribution, quantification and toxicity of cinnamaldehyde in electronic cigarette refill fluids and aerosols.

OBJECTIVE: The aim of this study was to evaluate the distribution, concentration and toxicity of cinnamaldehyde in electronic cigarette (e-cigarette) refill fluids and aerosols. METHODS: The distribution and concentration of cinnamaldehyde were determined in 39 e-cigarette refill fluids plus 6 duplicates using gas chromatography and mass spectrometry (GC/MS). A cinnamaldehyde toxicity profile was established for embryonic and adult cells using a live cell imaging assay, immunocytochemistry, the comet assay and a recovery assay. RESULTS: Twenty of the 39 refill fluids contained cinnamaldehyde at concentrations that are cytotoxic to human embryonic and lung cells in the MTT assay. Cinnamon Ceylon aerosol produced in a cartomizer-style e-cigarette was cytotoxic. Cinnamon Ceylon aerosols and refill fluid aerosols (80% propylene glycol or cinnamaldehyde/propylene glycol) made using a tank/boxmod e-cigarette were more cytotoxic at 5 V than 3 V. Using GC/MS, aerosols produced at 5 V contained 10 additional peaks not present in aerosol generated at 3 V. One of these, 2,3-butandione (diacetyl), was confirmed with an authentic standard. Cinnamaldehyde depolymerised microtubules in human pulmonary fibroblasts. At concentrations that produced no effect in the MTT assay, cinnamaldehyde decreased growth, attachment and spreading; altered cell morphology and motility; increased DNA strand breaks; and increased cell death. At the MTT IC50 concentration, lung cells were unable to recover from cinnamaldehyde after 2 hours of treatment, whereas embryonic cells recovered after 8 hours. CONCLUSIONS: Cinnamaldehyde-containing refill fluids and aerosols are cytotoxic, genotoxic and low concentrations adversely affect cell processes and survival. These data indicate that cinnamaldehyde in e-cigarette refill fluids/aerosols may impair homeostasis in the respiratory system.

Inhalable constituents of thirdhand tobacco smoke: chemical characterization and health impact considerations.

Tobacco smoke residues lingering in the indoor environment, also termed thirdhand smoke (THS), can be a source of long-term exposure to harmful pollutants. THS composition is affected by chemical transformations and by air-surface partitioning over time scales of minutes to months. This study identified and quantified airborne THS pollutants available for respiratory exposure, identified potential environmental tracers, and estimated health impacts to nonsmokers. In a ventilated 18 m(3) laboratory chamber, six cigarettes were machine-smoked, and levels of particulate matter (PM2.5) and 58 volatile organic compounds (VOCs) were monitored during an aging period of 18 h. Results were compared with field measurements taken in a smoker's home 8 h after the last cigarette had been smoked. Initial chamber levels of individual VOCs in freshly emitted secondhand smoke (SHS) were in the range of 1-300 µg m(-3). The commonly used SHS tracers 3-ethenylpyridine (3-EP) and nicotine were no longer present in the gas phase after 2 h, likely due mostly to sorption to surfaces. By contrast, other VOCs persisted in the gas phase for at least 18 h, particularly furans, carbonyls, and nitriles. The concentration ratio of acetonitrile to 3-EP increased substantially with aging. This ratio may provide a useful metric for differentiating freshly emitted (SHS) from aged smoke (THS). Among the 29 VOCs detected in the smoker's home at moderate to high concentrations, 18 compounds were also detected in simultaneously sampled outdoor air, but acetonitrile, 2-methyl furan, and 2,5-dimethyl furan appeared to be specific to cigarette smoke. The levels of acrolein, methacrolein, and acrylonitrile exceeded concentrations considered harmful by the State of California. An initial exposure and impact assessment was conducted for a subset of pollutants by computing disability-adjusted life years lost, using available toxicological and epidemiological information. Exposure to PM2.5 contributed to more than 90% of the predicted harm. Acrolein, furan, acrylonitrile, and 1,3-butadiene were considered to be the most harmful VOCs. Depending on which criteria are used to establish the separation between SHS and THS, 5-60% of the predicted health damage could be attributed to THS exposure. Benefits and limitations of this approach are discussed.