In-situ TD-GCMS measurements of oxidative products of monoterpenes at typical vaping temperatures: implications for inhalation exposure to vaping products
- DOI
- Language of the publication
- English
- Date
- 2022-06-30
- Type
- Article
- Author(s)
- Zhu, Jiping
- Niu, Jianjun
- Das, Dharani
- Cabecinha, Ashley
- Abramovici, Hanan
- Publisher
- Nature
Abstract
Vaping is gaining in popularity. However, there is still much that remains unknown about the potential risk and harms of vaping. Formation of oxidative products is one of such areas that are not well understood. In this study, we used an in-situ thermal desorption GC/MS method to investigate the formation of oxidative products of several monoterpenes at or below typical vaping temperatures. Among the five tested monoterpenes, the unchanged portion of the parent compound in the vapour varied from 97 to 98% for myrcene to 11–28% for terpinolene. The majority of formed oxidative products in the vapour have a molecular weight of 134 (loss of two hydrogens), 150 (insertion of one oxygen and loss of two hydrogen atoms) or 152 (insertion of one oxygen atom). Three products, likely to be p-(1-propenyl)-toluene, β-pinone and fenchol were also observed. This is the first in-situ thermal desorption GC/MS study to investigate the possible formation of oxidative products of monoterpenes, one of the major components in vaping liquids, at temperatures that are relevant to the vaping process. Although the toxicity of inhaling these oxidative products is not clear yet, allergic and irritation reactions associated with oxidized monoterpene oils are well documented. Therefore, potential adverse effects of inhaling these oxidative products during vaping could be investigated to help support human risk assessment.
Plain language summary
Health Canada is mandated to conduct research to protect health and welfare of Canadians. Vaping is gaining in popularity especially among young people, however there is still much that remains unknown about the potential health risk and harms of vaping. Only limited information is available on the inhalation toxicity of chemicals of vaping liquid. The formation of oxidative products in vaping aerosol may add additional uncertainties to inhalation toxicity associated with vaping. In this study, we have used an in-situ thermal desorption GC/MS method to examine the formation of oxidative products of monoterpenes, which are used in e-vaping liquid, to gain insight into chemical transformations of vaping liquid that may occur during vaping. These products could subsequently be inhaled by the individuals who vape. Our results demonstrated that chemicals in vaping liquids could undergo oxidative reactions and form various products in the vapour when they are heated. These products could subsequently be inhaled by the individuals who vape. Although toxic nature of these newly formed oxidative products is unknown, oxidation of monoterpene oils is known to enhance allergic and irritation reactions. Therefore, adverse effects of inhaling oxidative products during vaping should be investigated to support human risk assessment related to e-vaping liquid and devices.
Subject
- Health,
- Health and safety