The extent of harmful volatile organic compounds released when smoking after breaking the flavor capsules of heat-not-burn (HNB) cigarette products

A number of flavored capsule heat-not-burn (FC–HNB) tobacco products such as IQOS, Lil, and Glo have been introduced as a new generation of cigarettes. As they can release various types of volatile organic compounds (VOCs), it is important to assess the harmfulness associated with their use. Thus, the composition of VOCs in HNB cigarette vapor was evaluated to investigate the interactive roles of key variables controlling the relationships between VOC composition and capsule breaking, particularly the compositional changes induced by capsule breaking and release of flavor from FC-HNB cigarettes relative to regular products. As the capsules of FC-HNB cigarettes were broken, the total VOC concentrations increased by as high as eight times from 60.3 ± 0.48 to 488 ± 21.8 μg cig-1. The key VOC components released after breaking the flavored capsules were identified as ethyl butyrate (157 ± 13.6 μg cig-1; Lil), isoamyl acetate (76.9 ± 1.98 μg cig-1; Lil), and limonene (52.3 ± 3.29 μg cig-1; Glo). If the primary health risks of FC-HNB cigarette vapor are assessed using National Institute for Occupational Safety & Health (NIOSH) guidelines, 2,3-butanedinone exceeds the maximum daily intake limit (i.e., 0.05 mg day-1). Our study is expected to offer valuable insights into the harmful effects of direct and indirect exposure to various VOCs in FC-HNB products.