Atomizing liquid+atomizer heating and non combustion=steam smoke
Main components of tobacco oil
Secrets of Taste and Throat Beating
The source of the sense of throats - propylene glycol (PG)
Propylene glycol, which accounts for more than 50% of the components of tobacco oil, is an important food additive. In the appendix  of the Standard for the Use of Food Additives (GB 2760-2011) issued by the Ministry of Health of China, propylene glycol was approved to be used in "wet flour products (such as noodles, dumpling skin, wonton skin, and baked wheat skin)" and "pastries". Propylene glycol can absorb fragrance and bring a sense of throat attack.
Source of smoke - vegetable glycerin (VG)