Electronic cigarettes: incorporating human factors engineering into risk assessments

OBJECTIVE: A systematic review was conducted to evaluate the impact of human factors (HF) on the risks associated with electronic cigarettes (e-cigarettes) and to identify research gaps. HF is the evaluation of human interactions with products and includes the analysis of user, environment and product complexity. Consideration of HF may mitigate known and potential hazards from the use and misuse of a consumer product, including e-cigarettes. METHODS: Five databases were searched through January 2014 and publications relevant to HF were incorporated. Voluntary adverse event (AE) reports submitted to the US Food and Drug Administration (FDA) and the package labelling of 12 e-cigarette products were analysed. RESULTS: No studies specifically addressing the impact of HF on e-cigarette use risks were identified. Most e-cigarette users are smokers, but data on the user population are inconsistent. No articles focused specifically on e-cigarette use environments, storage conditions, product operational requirements, product complexities, user errors or misuse. Twelve published studies analysed e-cigarette labelling and concluded that labelling was inadequate or misleading. FDA labelling analysis revealed similar concerns described in the literature. AE reports related to design concerns are increasing and fatalities related to accidental exposure and misuse have occurred; however, no publications evaluating the relationship between AEs and HF were identified. CONCLUSIONS: The HF impacting e-cigarette use and related hazards are inadequately characterised. Thorough analyses of user–product–environment interfaces, product complexities and AEs associated with typical and atypical use are needed to better incorporate HF engineering principles to inform and potentially reduce or mitigate the emerging hazards associated with e-cigarette products.