Presented at American Public Health Association (APHA) Annual Conference.

Background: Electronic cigarettes (e-cigarettes) were introduced to the United States marketplace in 2007. By 2014, e-cigarettes dominated all other tobacco products used by youth. In May 2016, the Food and Drug Administration issued a final rule to implement graphic health warnings on cigarette packs and advertising, as required by the 2009 Tobacco Control Act. This study tested the hypothesis that youth's perceived harm of using e-cigarettes mediates the impact of seeing warning labels on their intentions to use e-cigarettes.

Methods: We used a cross-sectional quantitative research design to analyze the 2019 National Youth Tobacco Survey data from 12,563 students in middle schools (grades 6 – 8) and high schools (grades 9 – 12) in the U.S. We conducted the 4-step Baron and Kenny Mediation Analysis using Haynes' PROCESS macro analysis. Results: Our study results suggested a mediational process’s presence (path a: b = -.049, p < .001; path b: b = -.711, p < .001; path c: b = .189, p < .001; path c’: b =.186, p < .001), confirming the mediational role of youth's perceived harm of e-cigarettes on the relationship of seeing a warning label and their use intentions.

Conclusion: The study provided insights into the mediational role of the perceived harm of using e-cigarettes among youth. Through the Tobacco Control Act, the warning labels potentially serve as harm reduction products.