The Study
A Review of the Toxicity of Ingredients in e-Cigarettes, Including Those Ingredients Having the FDA’s “Generally Recognized as Safe (GRAS)” Regulatory Status for Use in Food
This study is like a teacher explaining why just because something is safe to eat doesn’t mean it’s safe to breathe. It shows examples of food ingredients that hurt lungs when turned into vapor — but it didn’t do any new experiments itself.
Analysis score
Maximum 5 for a narrative review.
Where the score came from
Some ingredients in e-cigarettes are approved for food, but that doesn't mean they're safe to breathe. When heated and inhaled, they can turn into toxic chemicals that hurt your lungs.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 51 / 100
Quality score
Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes—this means millions of youth using flavored vapes may be breathing harmful chemicals they were told were 'safe'.
- 2Diacetyl, cinnamaldehyde, PG, glycerol, and vitamin E acetate—all safe to eat—cause lung damage, cell death, and inflammation when vaped.
- 3Vitamin E acetate caused a major lung injury outbreak (EVALI).
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Nicotine & Tobacco Research
Year
2024
Authors
Nada O F Kassem, R. Strongin, Andrea M. Stroup, M. Brinkman, Ahmad El-Hellani, Hanno C. Erythropel, A. Etemadi, V. Exil, M. Goniewicz, Noura O Kassem, Theodore P. Klupinski, Sandy Liles, T. Muthumalage, Alexandra Noël, D. H. Peyton, Qixin Wang, Irfan Rahman, Luis G. Valerio
Related Content
Claims (10)
When people vape liquids containing propylene glycol or glycerol, the heat turns them into harmful chemicals like formaldehyde and acrolein, which can irritate the lungs, damage blood vessels, and mess with the body’s internal clock.
People got seriously sick from vaping THC oil, and scientists found that a common food ingredient called vitamin E acetate—safe to eat—was to blame when breathed in. So just because something is safe to eat doesn’t mean it’s safe to vape.
Just because a food ingredient is considered safe to eat doesn’t mean it’s safe to breathe in, especially when it’s heated up in a vape pen — the safety rules for eating and breathing are totally different.
Flavors used in e-cigarettes that are safe to eat can still hurt your lungs when you breathe them in, causing irritation, cell damage, and swelling.
Even though vitamin E acetate is considered safe to eat, when people breathed it in through vaping, it caused serious lung damage during the 2019–2020 outbreak — so being labeled 'safe for food' doesn’t mean it’s safe to inhale.
When e-cigarettes are labeled as 'GRAS' (which means 'generally recognized as safe'), it tricks people—especially teens—into thinking they’re harmless to breathe, even though no real science or official rules back up that idea.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.