Base extracts put the liquid in e-liquid. Their quality matters. Nicotine River only sells ultra pure, USP grade Vegetable Glycerin (VG), Propylene Glycol (PG), and Polyethylene Glycol 400 (PEG 400). No surprises. All bases are stored in HDPE plastic bottles to prevent environmental degradation. Available in sizes ranging from 500ml to 275 gallon totes.