Accounting for effects of system dynamics to improve accuracy of emissions reported in e-cig vaping machines.

Laboratory emissions testing of electronic cigarettes continues to be a focus in the tobacco research community. In particular, to inform policy regarding appropriate test protocols to regulate the manufacture, marketing and sale of tobacco products. This study aims to enhance current understanding of the way laboratory systems used to generate topography profiles and capture resultant emissions from inhaled tobacco products may interact with the device under test. A programmable emission system (vaping machine) is introduced and characterized. The operating envelope of this system is presented. This study demonstrates that the performance of an emissions system may be influenced by various factors, resulting in discrepancies between command puff parameter inputs and the observed puffs generated. The study findings conclude that any emissions system should be characterized with the desired test device to determine the effective operating range of the system under "Load" conditions. Furthermore, reporting emissions from electronic cigarettes as a function of "command" puff flow rate and cumulative volume result in under-estimation bias and may give rise to incorrect conclusions regarding the impact of product characteristics on emissions. Conversely, reporting emissions in terms of "observed" puff flow rate and cumulative volume reduces bias errors and limits opportunity for intentional misrepresentation of results.