Background: The variety of flavors available in emerging tobacco products, like electronic nicotine delivery systems (ENDS), is an important factor in the maintenance of product use by new and current users. Manufacturers of emerging tobacco products add flavoring chemicals to boost the sensation from vaping. This study examined the flavoring chemical composition of popular brands of ENDS refill solutions.<br/>Methods: A convenience sample of 150 refill solutions were selected based on popularity among regular users. Products were purchased from US-based online vendors and organized into eleven flavor categories. Products were selected specifically to analyze similarities and differences within and across various brands. Flavoring chemicals were extracted from products using liquid extraction and analyzed using GC-MS with Agilent J&W DB-624UI (30 m, 0.25 μm, 1.4 μm) column. The full-scan data was collected and data were deconvoluted using MassHunter Unknowns Analysis software. EI mass spectra of the deconvoluted peaks were compared to flavoring high resolution mass spectral library matching spectra (Flavor & Fragrance Natural & Synthetic Compounds library (Shimadzu, USA) along with NIST14 database (NIST, USA)). Principal Component Analysis (PCA) with Mass Profiler Professional Software was performed on selected data files. We also searched toxicological databases for available information on inhalation risk of each identified flavoring compound. Selected flavoring chemicals were quantified in order to assess transfer rates from ENDS refill solution to aerosol.<br/>Results: Total of 256 unique flavoring chemicals were identified in this study. On average, each refill solution contained 6 flavoring chemicals. The most common flavorings found in analyzed products were vanillin, isovanillin, ethyl maltol, triacetin, benzyl alcohol, benzaldehyde and menthol. The majority of the analyzed flavored products contained known respiratory irritants, including benzaldehyde, triacetin and acetyl pyrazine. The transfer rates from refill solution to aerosols of the analyzed flavoring chemicals were calculated.<br/>Conclusions: The majority of the chemicals used in flavored tobacco products are compounds commonly used as food flavorings or fragrances. Many of these chemicals have not been deemed safe to use for inhalation. Future regulation of flavored tobacco products should take into consideration type, concentration, and potential inhalation toxicity of inhaled flavoring chemicals.

Identification and quantification of flavoring chemicals in ENDS refill solutions

2019 Spring National Meeting

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