Document is current

Article History

Received: 14 June 2019

Accepted: 25 March 2020

First Online: 16 April 2020

Competing interests

: L.K. worked in the Institute of Occupational Medicine and Environmental Health, which is a public body, which, besides research works, offers expertise and conduct analyses on behalf of the Polish government and the industry. L.K. worked as an expert for the Polish National Committee for Standardization and for the European Committee for standardization of requirements and test methods for e-liquids and emissions. C.K. and declare no competing interests. J.K. and M.Z. worked in the Institute of Occupational Medicine and Environmental Health, which is a public body, which, besides research, offers expertise and conduct analyses on behalf of the Polish government and the industry. L.D. has previously (2010–2013) conducted research for several independent electronic cigarette companies. These companies had no input into the design, conduct or write up of the projects. She has also acted as a consultant for the pharmaceutical industry (2015, 2017) and as an expert witness in a patent infringement case (2015). HM has received honoraria for speaking at smoking cessation meetings and attending advisory board meetings that have been organized by Pfizer and Johnson & Johnson. M.L.G. received a research grant from Pfizer and served as a member of scientific advisory board to Johnson&Johnson, manufacturers of smoking cessation medications. We further confirm that this work has not been published and is not considered in any other journals for publication. <i>Data sharing</i>: Additional unpublished data and information are available upon request.