With the growing market of electronic cigarettes, there is also a growing need to consider standardized methods for analyzing these products. As with standardized methods for combustible products (e.g. ISO, Health Canada), any method for electronic cigarettes may require specification of conditions in which these products are analyzed. This work investigated varying relative humidity (RH) conditions and the effect RH had on the nicotine, water, propylene glycol (PG), and glycerin content in generic formulations of electronic cigarette liquids (e-liquids) where the initial nicotine was 2% and the PG:Glycerin ratio was 50:50 for all formulations while the water content ranged from 0 to 15%. Aerosol from these formulations was also produced under different relative humidity conditions, and analyzed for nicotine, water, PG, and glycerin. Additionally, gravimetrically determined total particulate matter mass yields were compared to device weight loss measurements. Conditions investigated were 40% RH and 60% RH at 22 +/- 3°C for both e-liquid and aerosol, and additionally 24% RH at 33 +/- 1°C for e-liquids.