Chemical Composition of Aerosol from an E-Cigarette: A Quantitative Comparison with Cigarette Smoke

Abstract

There is interest in the relative toxicities of emissions from electronic cigarettes and tobacco cigarettes. Lists of cigarette smoke priority toxicants have been developed to focus regulatory initiatives. However, a comprehensive assessment of e-cigarette chemical emissions including all tobacco smoke Harmful and Potentially Harmful Constituents, and additional toxic species reportedly present in e-cigarette emissions, is lacking. We examined 150 chemical emissions from an e-cigarette (Vype ePen), a reference tobacco cigarette (Ky3R4F), and laboratory air/method blanks. All measurements were conducted by a contract research laboratory using ISO 17025 accredited methods. The data show that it is essential to conduct laboratory air/method measurements when measuring e-cigarette emissions, owing to the combination of low emissions and the associated impact of laboratory background that can lead to false-positive results and overestimates. Of the 150 measurands examined in the e-cigarette aerosol, 104 were not detected and 21 were present due to laboratory background. Of the 25 detected aerosol constituents, 9 were present at levels too low to be quantified and 16 were generated in whole or in part by the e-cigarette. These comprised major e-liquid constituents (nicotine, propylene glycol, and glycerol), recognized impurities in Pharmacopoeia-quality nicotine, and eight thermal decomposition products of propylene glycol or glycerol. By contrast, approximately 100 measurands were detected in mainstream cigarette smoke. Depending on the regulatory list considered and the puffing regime used, the emissions of toxicants identified for regulation were from 82 to >99% lower on a per-puff basis from the e-cigarette compared with those from Ky3R4F. Thus, the aerosol from the e-cigarette is compositionally less complex than cigarette smoke and contains significantly lower levels of toxicants. These data demonstrate that e-cigarettes can be developed that offer the potential for substantially reduced exposure to cigarette toxicants. Further studies are required to establish whether the potential lower consumer exposure to these toxicants will result in tangible public health benefits.

Reduced biological effect of e-cigarette aerosol compared to cigarette smoke evaluated in vitro using normalized nicotine dose and RNA-seq-based toxicogenomics

“…Furthermore, Margham et al reported a nicotine dose per puff of 0.032 mg of nicotine for the Vype ePen and 0.17 mg for 3R4F smoked at a variant of the HCI regimen (CORESTA CRM81), and HCI, respectively. Based on these numbers there is overall a good agreement between the data from Margham and colleagues 30 and the dilution ratio we used for 3R4F and Vype ePen to achieve nicotine dose matching and one e-cigarette dose exceeding 3R4F nicotine by approximately two-fold. After one-hour exposure, different endpoints were investigated at 24 hrs and 48 hrs post treatment, including total RNA for differential RNA-seq profiling.…”

“…The commercially available Vype ePen e-cigarette (Nicoventures, UK) is a closed modular device and the 'Blended Tobacco' variant was used containing18 mg/ml nicotine replaceable e-liquid cartridge composed of 25% (w/w) propylene glycol, 48.14% vegetable glycerine, 25% water, and (<1%) blended tobacco flavor 30 .…”

Electronic cigarette aerosols suppress cellular antioxidant defenses and induce significant oxidative DNA damage

“…formaldehyde, acetaldehyde, acrolein, and toluene) are significantly lower (9- to 450-fold lower) than those in cigarette smoke [20, 24], and in many cases (e.g., NNN and NNK) comparable with the trace amounts present in nicotine replacement products [25–27]. However, recent studies, have shown that specific toxicants and carcinogens present in EC aerosols can reach levels equal (e.g., acetaldehyde and chromium) to or exceeding (e.g., formaldehyde, and nickel) to those found in cigarette smoke, particularly as the power of the device increases [15, 22].…”

Short‐Term E‐Cigarette Exposure Increases the Risk of Thrombogenesis and Enhances Platelet Function in Mice

“…Nonetheless, the negative consequences of e‐cigarettes, including their impact on the cardiovascular system,7 remain a subject of debate, especially in light of the fact they are not emission‐free devices. To this end, e‐cigarettes in fact share some of the toxicant profile of conventional cigarette smoking and may expose users to similar health risks 8, 9, 10…”