What makes residents more willing to participate in source separation of waste masks under the COVID-19 pandemic?

With the outbreak of the novel coronavirus (COVID-19), the generation of a large amount of medical waste brought a rude shock to the existing solid waste management system. Since masks constitute the most common household medical waste under the COVID-19 pandemic, their effective collection and treatment can significantly reduce the potential risks for secondary transmission, and this concern has attracted worldwide attention. Taking Macau City as a case study, this research tried to identify factors that can influence residents’ behavioral intentions toward the source separation of COVID-19 waste masks. The extended theory of planned behavior (TPB) model is used to examine the influence factors of the source separation behaviors of 510 respondents. The results show that the main factors that positively affected respondents’ behavioral intentions toward waste-mask source separation are: cognitive attitude, convenience, and perceived behavioral control, and among these, cognitive attitude has the highest influence. Subjective norm is also proved to be the weak factor to improving behavioral intention. Policy advocacy, and demographic variables have no significant effect on behavioral intention. The results of this study can help decision makers and managers formulate effective strategies to increase residents’ participation in the source separation of waste masks. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10163-022-01513-7.