Characterising vaping products in the United Kingdom: an analysis of Tobacco Products Directive notification data.

An analysis of reports to the United Kingdom's Medicines and Healthcare products Regulatory Agency by manufacturers of vaping products shows that (i) these products have a large range of ingredients and emissions, (ii) the reporting system is unstandardized in terms of reporting requirements, and (iii) for quantified emissions, median levels are for the most part below published safe limits for ambient air.