Vaping lung illness: Harmful chemicals found in e cig flavoring juice Does Vaping Cause Lung Cancer? What We Know (and Still Don't) Don't be fooled by the smoke or the flavor. Vapes and cigarettes both contain toxic chemicals that can harm your body. #BeSafeDontVape #TobaccoFreeGeneration Do you really know what's in your vape? There's no safe vape. Besides nicotine, vapes contain many other harmful substances. Formaldehyde, arsenic and lead have all been found inside common vapes.