It is known that propylene glycol (PG), vegetable glycerin (VG), and flavouring chemicals can break down under heat during vaping, producing harmful chemicals called carbonyls. However, less is understood about how flavour chemicals themselves produce carbonyls and how the ingredients in juice interact to create these compounds. Additionally, the research on their effect on human health and the actual amounts that are inhaled, is vast but limited, since it cannot be conducted in a real setting – ie in one’s lungs.
The 2021 study, “Carbonyl Composition and Electrophilicity in Vaping Emissions of Flavoured and Unflavoured juice“, analyzed the carbonyl chemicals released when vaping PG-VG (the main juice solvents) and four flavoured juice containing trans-2-hexenol, benzyl alcohol, l-(-)-menthol, or linalool. Using advanced testing methods (gas and juice chromatography-mass spectrometry), researchers identified and measured 14 different carbonyl compounds.
PG-VG alone produced the highest levels of formaldehyde, acetaldehyde, and acrolein—three harmful chemicals, while flavoured juice, generated a wider variety of carbonyls. Some of these directly formed through the chemical breakdown of flavouring ingredients. For example, trans-2-hexenol became trans-2-hexenal, and benzyl alcohol transformed into benzaldehyde.
The study also found evidence that some carbonyls (such as formaldehyde and trans-2-hexenal) can react with biological molecules in the body, raising concerns about potential health risks. By analyzing the chemical reactivity of these carbonyls, researchers further explained how different compounds produced during vaping could interact with biological systems. Overall, the study highlighted the presence of harmful carbonyl compounds in vaping emissions and emphasized the potential health risks associated with these chemicals.
Source: vapingpost.com