Disaster risk communicators have long contemplated the significance of sociodemographic dimensions in better understanding and characterising an audience's perceptions. Indeed, various societal and personal factors have been considered as predictors of individual risk attitudes, perceptions and behaviours for an array of hazard types. However, such risk communication issues have only recently started to be explored within the emerging field of conjoint natural and technological disasters, called Natech. In this context, delineating the sociodemographic profile of individuals and appreciating the implications of these aspects on Natech risk communication can assist risk managers in tailoring effective risk communication strategies. This study investigates, among other items, the effects of residents' gender, age, household size, income and educational level on their perceptions of information disclosure concerning Natech risk. The approach draws upon the framework of the Situational Theory of Problem Solving in an attempt to conceptualise the complex issue of information deficiency. Taking into account individuals' situational perception elements, the research focuses on certain cross-situational, sociodemographic features that serve as external, determining factors that shape their problem-solving motivation. Data has been collected from households near industrial parks in Osaka and Kobe in Japan and Yeosu, Suncheon, Gwangyang and Ulsan in S. Korea. The results of our regression analysis indicated mostly weak and insignificant effects, except for gender and age that suggested negative and positive influences to individuals' communicative attitudes, respectively. The implications of the institutional differences between the two countries are also discussed within the sphere of chemical and Natech risk communication.