Fig. 1

Percent Difference of Labeled vs. Measured Nicotine Concentration (N = 51). Comparisons of nicotine percentages using common units of mg/mL were made using an e-liquid density correction to convert nicotine mg/g to mg/mL. Density data are not shown. Measured nicotine concentrations (Grey Area) were lower than labeled nicotine concentrations (Outlined Areas) for the majority of evaluated commercial disposable/non-chargeable e-cigarette products. The percent differences from the label (Figure 1, right column) ranged from -50.1 to 13.9%