Community Request Diacetyl Center for Research on Ingredient Safety All about vapes what's in them, how do they work, and more Philip Morris International Vape Juice Ingredients: What's Inside Your E Liquid? VITAE Glass Do you or a young person you know vape? Vapes are not water. The main ingredient in vapes is propylene glycol, vegetable glycerine or glycerol. They can contain the same harmful chemicals Because tobacco companies aren't required to tell us what's in vapes, we wind up being lab rats for their dangerous, addictive products. So, let's be clear (since Big Tobacco won't be) Vapes Ingredients The Health Warning Label for Vape Product Packaging