The harmful chemicals in vape juices SEATCA 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. what is in vape juice Swell By Aqua E Juice 60ml $ PMTAs for Juice Head Synthetic Nicotine E Liquid Accepted by FDA Most vapes contain toxic chemicals that are bad for your health. Some are added to make the vapes taste or smell nice, and others are created when the battery heats the liquid.