Leading commercial electronic cigarettes were tested to determine bulk composition. The e-cigarettes and conventional cigarettes were evaluated using machine-puffing to compare nicotine delivery and relative yields of chemical constituents. The e-liquids tested were found to contain humectants, glycerin and/or propylene glycol, (⩾75% content); water (<20%); nicotine (approximately 2%); and flavor (<10%). The aerosol collected mass (ACM) of the e-cigarette samples was similar in composition to the e-liquids. Aerosol nicotine for the e-cigarette samples was 85% lower than nicotine yield for the conventional cigarettes. Analysis of the smoke from conventional cigarettes showed that the mainstream cigarette smoke delivered approximately 1500times more harmful and potentially harmful constituents (HPHCs) tested when compared to e-cigarette aerosol or to puffing room air. The deliveries of HPHCs tested for these e-cigarette products were similar to the study air blanks rather than to deliveries from conventional cigarettes; no significant contribution of cigarette smoke HPHCs from any of the compound classes tested was found for the e-cigarettes. Thus, the results of this study support previous researchers' discussion of e-cigarette products' potential for reduced exposure compared to cigarette smoke.

Summary Several machine-based puffing regimes for collection of e-cigarette aerosol were evaluated with the objective of recommending one regime for standardization. The study involved a comparison of several candidate regimes for which puff volume, duration, interval, profile shape, and puff number were defined and varied. Testing was conducted at four laboratories using seven e-cigarette test products. Each participating laboratory generated and analyzed aerosol from the test products for glycerin, propylene glycol, water, and nicotine using the candidate regimes. Results were compared within each product’s data set to understand the impact of the regimes on product yield, consistency of results, and reliability of the testing equipment. Each of the regimes evaluated was determined to be fit for purpose for the range of products tested. Based on specific selection criteria, the recommended collection parameters are a square-shaped 55-mL puff of 3 s duration with a puff frequency of one puff every 30 s. Standardized reporting parameters include aerosol collected mass (ACM), puff count, and e-cigarette weight loss along with analyte yield on a per-puff basis and total-puffs basis.

Summary On May 10, 2016, the U.S. Food and Drug Administration (FDA) published a Final Rule that extended its regulatory authority to all tobacco products, including e-cigarettes, cigars, hookah and pipe tobacco (Deemed Products). Effective August 8, 2016, this decision greatly expanded the scope of tobacco products being regulated by FDA and introduced significant testing challenges that need to be addressed. The major challenge for cigars in particular is testing as well as generation of accurate and reliable data, in the absence of certified reference products and standardized methodology for a product category with significant complexity and high inherent variability. In this article, we provide an overview of recent studies as well as active opportunities and on-going challenges associated with regulating and testing cigars. To the best of our knowledge, this is the first comprehensive review of non-clinical research for this product category (cigars). We are therefore convinced that, tobacco scientists and farmers, analytical chemists, cigar consumers, tobacco legal counsels, state and federal regulatory authorities will find this review beneficial and insightful.

Summary Commercial cigarettes were analyzed for harmful and potentially harmful constituents (HPHCs) in tobacco and smoke to investigate temporal product variability independent of analytical variability over one week, one year, and three years. Cigarettes from the worldwide market with various design features were collected over a 3-year period, stored, and tested concurrently for HPHCs to minimize analytical variability; repeat testing of reference cigarette 3R4F was included as an analytical control for the study design. Physical parameters were found to be relatively consistent. No trends in variability were noted based on blend type, smoke analyte matrix, or magnitude of an HPHC's yield. Combustion-related HPHCs generally showed low variation. Long-term batch-to-batch variability was found to be higher than short-term variability for tobacco-related compounds that have the potential to vary over time due to weather and agronomic practices. “Tar”, nicotine, and carbon monoxide were tested in multiple labs and showed greater lab-to-lab variability than batch-to-batch variability across all phases. Based on the results of this study, commercial cigarette products appear to have relatively low product variability. The low analyte variability noted in this study with products tested under unconventionally controlled analytical conditions serves to indicate that analytical variability may be a significant contributor to overall variability for general product testing over time and in interlaboratory studies. Laboratory controls and using a matched reference product across studies and between laboratories are important to assess testing differences and variability.

SUMMARY A collaborative study among 20 participating laboratories was conducted in an effort to publish a recommended method for determination of phenols in mainstream cigarette smoke. The study was conducted using 10 test samples including reference cigarettes and commercial products from various regions (ISO 3308 total particulate matter 1–16 mg/cig) smoked under two regimes (ISO 3308 and ISO 20778). Health Canada method T-114 was chosen as a basis for the analytical methodology and therefore mainstream cigarette smoke was trapped on 44-mm glass fiber filter pads which were subsequently extracted with 1% aqueous acetic acid for analysis by high performance liquid chromatography with fluorescence detection. Statistical analysis was carried out following ISO 5725 to generate repeatability (r) and reproducibility (R) data for results from linear and rotary smoking. For reproducibility (R) expressed as a percentage of mean yield across all of the studied products and both smoking regimes, values ranged from 17–150%. The lowest “tar” yielding products had the most variable data. Results trended as expected for total particulate matter, blend type, regime, and relative analyte yields. Results supporting a robust method for hydroquinone, resorcinol, catechol, phenol, o-cresol, m-cresol, and p-cresol are reported herein and support establishment of CRM 78, ISO 23904 and ISO 23905 standardized methods. [Contrib. Tob. Nicotine Res. 32 (2023) 18–25]