Adult harm perceptions, purchase, and use related to synthetic vs. tobacco-derived nicotine vaping products: A mixed-methods study

Objective: Synthetic nicotine (SN) e-cigarettes emerged on the market as an alternative to tobacco-derived nicotine (TDN) vaping products. It is critical to understand the harm perceptions, purchase, and use of SN vs. TDN e-cigarettes. Methods: From November 2021 to February 2023, we conducted intercept interviews with 263 adult customers at 37 vape shops in Southern California. Self-reported use and harm perceptions towards SN vs TDN e-cigarettes were examined. A qualitative analysis of researcher-obtained photographs of vaping items just purchased by customer participants was conducted. Results: Past 30-day SN e-cigarette use was reported by 44 (16.7 %) customers. Past 30-day SN e-cigarette users vs. non-users reported vaping on more days in the past month (29.3 vs. 26.1 days, p = 0.02). Overall, 23.8 % of participants perceived SN e-cigarettes as less harmful than TDN ones; never-smoking vapers and dual users perceived SN e-cigarettes as less harmful than salt-based TDN e-cigarettes. Among 44 customers who purchased SN products (verified through qualitative analysis of photographs), only 13 (29.6 %) self-reported using SN products in the past month, while 5 (11.4 %) indicated they were not aware of the existence of SN products. Most SN vaping products (71.4 %) displayed a modified "tobacco-free" warning label. Conclusions: Misperceptions about SN e-cigarettes were documented in this study, including the perception that SN is either less or more harmful than TDN. Further, some customers may be unknowingly purchasing and using SN e-cigarettes. Regulating "tobacco-free nicotine" terminology in SN vaping products marketing is suggested. SN product labeling should not imply that SN is safe/safer than TDN.