Disposable E-Cigarettes and Metal Emissions: A Case Study of Corrosion-Related Artefacts and Implications for Toxicological Interpretation

E-liquids stocked inside unregulated disposable vaping devices are subjected to corrosion effects from their chemical interaction with metallic parts during their likely long-time storage. Consequently, aerosols generated from these e-liquids likely contain abundant yields of metallic elements, an outcome that becomes more plausible and concerning in the absence of quality control in large unregulated markets. In order to address the potential effects of corrosion in disposable devices, we considered the wealth of experimental data obtained in a recently published article (1) that thoroughly quantified metallic elements in e-liquids and aerosols of three brands of unregulated but popular disposable devices (3 ELF Bar, 2 Flum Pebble, and 2 ESCO Bar). Nickel levels steadily increased as all devices were puffed in sequences of 100 puffs up to 1,500 puffs, while the ESCO Bar and Flum Peeble respectively exhibited high levels of lead and antimony. However, the authors also report high levels of these metals in e-liquids of the devices already before testing them. Using the authors’ own data, we highlight that these experimental results are consistently explained by corrosion effects in e-liquids kept inside devices stored in the likely long-time between their manufacture and their testing. Without considering this initial defective state the authors presented incomplete comparisons of their results with those of other vaping devices (refillable and cartridge based) and with tobacco smoke. We also show that the authors overestimated cancer and non-cancer risks by assuming an unrealistic lifetime risk model and for failing to account for the appropriate exposure scenario inherent in vaping. Our results might highlight the pressing necessity to regulate and implement quality control standards to the whole class of disposable vaping devices.