Updated and editorially reviewed by VapePoint: August 2, 2026. General information only; not personal medical advice.
Formaldehyde is a chemical classified as carcinogenic to humans at relevant levels of exposure. It is not unique to vaping, and studies conducted over the years have failed to show that formaldehyde in dangerous amounts enters the body as a result of using e-cigarettes.
Why do studies produce different results?
The levels of formaldehyde and carbonyls in aerosol are affected by the type of device, power, coil, PG/VG ratio, flavorings, puff duration, and measurement conditions. Studies have found substantial differences between methods, and conditions involving overheating or a “dry puff” can sometimes change the result significantly.
Therefore, there is no single figure that can be attributed to every device or every user. A single laboratory study cannot establish that all vaping is equally dangerous, nor can it establish that no usage conditions could produce concerning exposure.
What can be said cautiously?
A systematic review found that in a large proportion of studies, formaldehyde and acrolein exposure among vapers was lower than among smokers. A more recent study emphasizes that flavors, power, and the base material can also affect carbonyl emissions.
From a harm-reduction perspective, the relevant comparison is primarily among adults who smoke and switch completely from smoking. Although studies provide a basis for cautious optimism, vaping is not risk-free, and results from one device do not guarantee the same results for another product or for long-term use.