An exploration into "do-it-yourself" (DIY) e-liquid mixing: Users' motivations, practices and product laboratory analysis.

Background: E-liquids are commercially available and manufactured, however some users of e-cigarettes prefer to prepare them at home (Do-it-Yourself; DIY) using individual ingredients. To date there is a paucity of research on how and why users make their own e-liquids.

Methods: Forty-one European and US based exclusive users of e-cigarettes (ex-smokers) were individually interviewed.

Can Established Vapers Distinguish Different PG:VG Ratios? A Pilot Study.

Objectives: Using the triangle test, this study explores whether established vapers can distinguish small differences between e-liquid propylene glycol: vegetable glycerin (PG:VG) ratios at fixed levels of nicotine and flavor, in order to examine the extent to which solvent ratios affects sensory experiences.

Methods: Watermelon flavored e-liquids (16mg/mL nicotine) used for this study differed in the ratio of PG:VG (30:70, 50:50; 70:30). Current vapers were randomized to one of 3 possible study conditions differing by PG:VG ratio.