Updated and editorially reviewed by VapePoint: August 2, 2026. General information only; not personal medical advice.
Diacetyl is a flavoring and aroma substance used in various industrial applications. It became widely known after high and prolonged occupational exposures were linked to a rare and severe obstructive lung disease, bronchiolitis obliterans.
What is the connection to vaping liquids?
Tests of liquids and aerosols have found that a small proportion of products may contain diacetyl or related substances, especially in connection with flavorings. Composition varies between products, batches, and conditions of use. Therefore, exposure cannot be inferred from the label or flavor alone. We recommend buying e-liquids only from official vape shops that import branded products from globally recognized brands with a strong reputation.
What cannot be determined?
The disease described in factory workers does not prove that a particular vaping product will cause the same disease, but it also does not justify saying that inhalation exposure is unimportant. Currently, there is insufficient evidence to accurately quantify the risk for every user, every liquid, or every level of exposure.
The fact that a flavoring is approved for use in food does not automatically make it suitable for inhalation. With regulated products, ingredients and test documents can be checked—this helps reduce the risk to a very low level.
Making an informed choice
For adults who smoke, completely switching from cigarettes can reduce exposure to many substances in smoke. For people who do not smoke, or those with respiratory symptoms, starting to vape is not a medical solution. If you experience shortness of breath, chest pain, or a persistent cough, stop using the product and seek medical evaluation.