Cherry Flavored E-Cigarette Smokers Inhaling Benzaldehyde

Maciej Goniewicz

Dr. Maciej Goniewicz Interview with:
Maciej Goniewicz, PhD, PharmD

Assistant Professor of Oncology, Department of Health Behavior
Roswell Park Cancer Institute (RPCI

Medical Research: What is the background for this study? What are the main findings?

Goniewicz: In addition to nicotine and its solvents (like propylene glycol and vegetable glycerin), a majority of e-cigarettes contain flavorings. Users of e-cigarettes can choose their favorite flavor among hundreds of various options, including fruit, coffee, menthol, vanilla, chocolate, candy flavors, and tobacco.  Although many flavorings used in e-cigarettes are recognized as safe when used in food products, little is known about their potential toxicity when inhaled.

In this study we measured one such flavoring, benzaldehyde. This flavoring is commonly used in food and cosmetics. We know that there is little to no toxicity if we eat this compound or if we apply it on our skin. However, workers who regularly inhale a high concentration of benzaldehyde often report irritation of their eyes and throat. In this study, we tested 145 e-cigarette products, and we found benzaldehyde in 108 products. Interestingly, the highest levels of benzaldehyde were detected in cherry-flavored products. 

e-cigarette CDC imageMedical Research: What should clinicians and patients take away from your report?

Goniewicz: Although this study looked only at a single flavoring, our findings suggest that regular e-cigarette users may be exposed to benzaldehyde over a long time. Those users who vape cherry-flavored products may be at higher risk of experiencing some side effects from inhaling benzaldehyde.  If an e-cigarette user experiences some unpleasant side effects from the product, he or she should consider trying a product with a different flavor. Since the majority of tested products had lower benzaldehyde levels than tobacco cigarettes, those users who quit smoking with e-cigarettes should not come back to tobacco cigarettes.

Given the uncertainty surrounding adverse health effects stemming from long-term inhalation of flavoring ingredients such as benzaldehyde, clinicians need to be aware of this emerging risk and ask their patients about use of flavored e-cigarettes.

Medical Research: What recommendations do you have for future research as a result of this study?

Dr. Goniewicz: The potential effects flavor compounds may have on the respiratory health of e-cigarette users are unclear. This study only evaluated the presence of one chemical in e-cigarette vapors. We did not look at whether the levels we reported in our study can actually cause any side effects in e-cigarette users. Future studies should look at actual biological responses to inhaling flavored e-cigarette vapors. Our study indicates that future human studies need to assess a variety of flavorings, since the potential side effects may be related to a specific flavor. 

Medical Research: Is there anything else you would like to add?

Goniewicz: Although this study found that cherry-flavored e-cigarettes may expose users to benzaldehyde doses similar to those from tobacco cigarettes, it does not suggest that e-cigarettes are as toxic as tobacco products. Tobacco cigarettes are highly dangerous and deadly products, and there have been several studies showing significantly reduced toxicity of e-cigarettes compared to tobacco products. Since the majority of e-cigarettes tested in this study had lower benzaldehyde levels than tobacco cigarettes, those users who quit smoking with e-cigarettes should not come back to tobacco cigarettes.


Leon Kosmider, Andrzej Sobczak, Adam Prokopowicz, Jolanta Kurek, Marzena Zaciera, Jakub Knysak, Danielle Smith, Maciej L Goniewicz.Cherry-flavoured electronic cigarettes expose users to the inhalation irritant, benzaldehyde. Thorax, 2016; thoraxjnl-2015-207895 DOI:1136/thoraxjnl-2015-207895

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Maciej Goniewicz, PhD, PharmD (2016). Cherry Flavored E-Cigarette Smokers Inhaling Benzaldehyde 

Last Updated on January 29, 2016 by Marie Benz MD FAAD