The main chemical substances of electronic cigarettes include nicotine, propylene glycol, vegetable glycerin, flavoring spices or essences, etc.
E-liquids usually contain nicotine, various flavors, and organic chemical solvents (such as propylene glycol, glycerin, etc.) that help create aerosols. Among them, glycerin is safe to eat, but if glycerin contains more impurities, it may irritate the bronchial mucosa; propylene glycol is usually used as antifreeze, humidifier and food additive, and it is safe to eat under the conditions of national regulations, but Inhalation of large amounts of propylene glycol as fume can cause respiratory irritation.