Critical Appraisal of Exposure Studies of E-Cigarette Aerosol Generated by High-Powered Devices*

SUMMARY Currently low-powered pods and disposables overwhelmingly dominate consumer preference of vaping products. Yet, despite its marginal usage, third generation high power low resistance (sub-ohm) devices are still used frequently to generate aerosols for assessing the toxicity of vaping aerosols. All these studies operate these devices under the CORESTA Recommended Method 81 protocol or with slight modifications, with airflow rates around 1 L/min. This experimental set up is concerning, since we have published various articles showing that much higher airflow rates (around 10 L/min) are a necessary experimental condition for these devices to generate aerosols that avoid overheating and large production of toxic byproducts. In a previous recent article, we replicated aerosol generation from a high-powered device integrated into a computerized exposure system used to expose in in vitro and in vivo systems. After careful calibration, we identified the experimental conditions for this device to avoid generating aerosols under an Overheating Regimen that would generate a repellent aerosol for human users. Applying the experimental results of this study, we show in this critical review that all studies using this same device exposed biological systems to overheated and aldehyde-loaded aerosols, with about half of the studies also delivering excessive nicotine concentrations. Some studies reported the presence of carbon monoxide, suggesting evidence of advanced wick pyrolysis. Most of the reviewed studies are irreproducible for failing to provide sufficient information of their aerosol generation procedures. Our results raise questions on the relevance of this literature to assess the risk profile of vaping products. Finally, we provide guidelines to improve the protocols of aerosol generation methodology in emission and exposure studies. [Contrib. Tob. Nicotine Res. 34 (2025) 202–221]