8 Vape Juice Ingredients to Avoid Toxic e Liquid Flavors Vaping the sweetener sucralose may produce toxic chemicals Nicotine, propylene glycol, sweet flavorings, and various toxic chemicals like carcinogens and heavy metals are found in vape juice, posing health risks, especially to youth. Myth! ~ Have you heard that e liquid is full of harmful chemicals? It's not true it's only got 4 ingredients. #vaping #vape #vapeuk #ecig #vapour