Comparison of e-cigarette nicotine concentrations used by US adults and youth

Nicotine concentration is a key characteristic of modern e-cigarette products. This study aims to illuminate age-related differences and temporal trends in nicotine concentrations to help inform strategies to reduce nicotine-related public health risks.

Data were drawn from the US Population Assessment of Tobacco and Health Study Wave 5 (December 2018-November 2019), Wave 6 (March-November 2021) and Wave 7 (January 2022-April 2023) and analysed in 2026. χ² tests and multivariable regressions were used to compare nicotine levels used in e-cigarettes (ie, unknown, 0%, 0.1-1.7%, 1.8-4.9%, 5.0%+) by age groups at Wave 7 and examine trends in nicotine concentrations for adults (18+) across Waves 5-7.

Among individuals currently using e-cigarettes at Wave 7 (n=3782), about 60.1% of those aged 12-14 and 51.2% of those aged 15-17 reported not knowing nicotine concentrations, and young adults aged 18-24 were the most likely to report using 5.0%+ (38.7% prevalence vs 24.4% of those aged 25-34, 14.6% of 35-54 and 4.3% of 55+). The proportion of adults responding 'I don't know' increased from 15.8% at Wave 5 to 23.8% at Wave 7, especially among those aged 18-24 (13.9-26.0) and 25-34 (13.9-23.6%). The proportion of adults reporting 5.0%+ increased from 13.9% to 24.4%(p<0.0001), and those reporting 0.1-1.7% decreased from 49.2% to 35.4% (p<0.0001).

Over half of youth using e-cigarettes were unaware of the nicotine concentration. High-concentration products have become increasingly prevalent, especially among young adults. Clearer nicotine concentration labelling on e-cigarette products and continued surveillance of nicotine levels are needed.