.../... No more smoking for Scott Riddle. Now he vapes. When users inhale from it, a heating element vaporizes the liquid in the mouthpiece cartridge, which contains nicotine and propylene glycol - a common chemical approved for use in foods, cosmetics, and smoke machines. E-cigarettes can have varying levels of nicotine, to match regular, light and ultralight cigarettes. he said. "I'm able to taste foods better now, and can smell better ...