Individual flavor chemicals in refill fluids with a total concentration of flavor chemicals ≥ 10 mg/mL (a) Two Apples, (b) Peach, (c) Ry4 Tobacco, (d) Mints and Two Mints, (e) Q Menthol (Authentic), (f) Cheesecake, (g) Q Honeydew Drop, (h) Q Pina Colada, (i) HP Sweet Accelerator. The x-axis shows flavor chemicals that were > 1 mg/mL, and the y-axis shows the concentration of individual flavor chemicals.