(Reminder: Secondhand smoke is dangerous, especially for children. The best way to protect loved ones is to quit smoking.)

The smoke from electronic cigarettes is not considered secondhand smoke?

First look at the definition of secondhand smoke: secondhand smoke, also known as passive smoking and environmental tobacco smoke, is a mixture of smoke released from the burning end of cigarettes or other Tobacco.

Simplify the point: tobacco smoke

So it is clear that e-cigarettes are not secondhand smoke. Because the ingredients of e-cigarettes are nicotine, propylene glycol, glycerin, and flavoring, they do not contain tobacco. (Incidentally, nicotine is prevalent in the Solanaceae family, not unique to tobacco.)

So, the mist exhaled by the e-cigarette and cigarette smoke mist is more harmful?

For the e-cigarette "secondhand smoke" problem, the CDC has taken a study of the composition of the urine of e-cigarette users, a total of two scientific research.

The first was in 2014, CDC researchers released a research paper on VOCs (volatile organic compounds) in the smoke of traditional tobacco and e-cigarettes, showing that the VOCs metabolite VOCMs content in the urine of e-cigarette users is similar to that of people who never smoked, while the concentration of VOCMs in smokers is significantly higher than that of e-cigarette users, smokeless tobacco users and people who never smoked.

PS: VOCMs are the metabolites produced by the body's processing of VOCs, which are excreted through urine.VOCs (volatile organic compounds) are a collective term for organic compounds that are volatile under certain conditions, and harmful substances such as benzene, toluene, and formaldehyde, which we often hear about, are all in VOCs.

The second is July 2020, research results show that the content of tobacco-specific nitrosamines (TSNA) metabolite NNAL in the urine of e-cigarette users is extremely low, only 2.2% of cigarette users, is 0.6% of smokeless tobacco (snuff, chewing tobacco, etc.) users.

More than 70 carcinogens have been identified in conventional tobacco and secondhand smoke, of which tobacco-specific nitrosamines (TSNA) are the most important carcinogens in tobacco and the smoke produced by its combustion, and are extremely harmful to the health of smokers and secondhand smokers.

TSNA contains NNK, NNN, NAB, NAT and so on. Among them, NNK and NNN have been identified by the World Health Organization (WHO) as the major contributors to the carcinogenicity of cigarette smoke.

NNAL is a metabolite produced by the body's processing of nitrosamines (TSNAs) and is excreted through the urine. People inhale nitrosamines (TSNAs) through the use of tobacco products or secondhand smoke, and then the metabolite NNAL is excreted in the urine.

The results of the study showed that the average urinary NNAL concentration was 993.3 ng/g creatinine for smokeless tobacco users, 285.4 ng/g creatinine for cigarette users, and 6.3 ng/g creatinine for users of e-cigarette products, which means that the amount of the tobacco-specific nitrosamine metabolite NNAL in the urine of e-cigarette users was only 2.2% of that of cigarette users and 0.6% of that of smokeless tobacco users.

Therefore, these two most harmful volatiles are not present, at least not in the same large and significant quantities as in cigarettes, or in e-cigarettes.

In summary, both conceptually and compositionally, the smoke from e-cigarettes periodred "secondhand smoke" in the traditional sense. However, because e-cigarettes are relatively new, there is no way to have a large number of conclusions and data references in a short period of time, and there is no way to quote the exact and complete conclusion, so we should look forward to more scientific research results. Look at it rationally.