Propylene Glycol Side Effects (Toxicity, Allergy, Vape) Propylene glycol, a component of electronic cigarette liquid, damages epithelial cells in human small airways Respiratory Research Springer Nature Link Vaping propylene glycol and vegetable glycerine may lead to lung inflammation We break down the key differences between traditional cigarettes and e cigarettescovering: 1 Their compositions and ingredients. 2 The health risks associated with both. 3 Nicotine levels and addiction potential. 4 The impact Propylene Glycol Vape (PG) Svapoebasta