Asbestos and humidifier disinfectant cases are representative environmental health disasters with a large number of victims that demand social explanations and political interventions. Understanding disasters as discursive and political constructs with material consequences, this paper analyzes how asbestos and humidifier disinfectant cases were constructed as environmental health disasters. Examining how disasters are characterized, understood, and resolved can reveal social and political responsibilities around safety within a society, providing practical implications to investigating and settling disasters. This paper highlights that the state responsibilities were particularly emphasized by characterizing the two cases as environmental health problems. First, the paper traces how the first comprehensive environmental health policies were made and how environmental disasters were legally and institutionally defined. Then it analyzes processes by which asbestos and humidifier disinfectant cases were characterized as environmental health disasters and policy measures established as consequences. Lastly, by comparing the two cases, this paper considers the implications of the increasing presence of environmental health problems in Korean society. Asbestos and humidifier disinfectant cases illustrate that characterizing the incidents as environmental health disasters was decisive in demanding governmental intervention and defining the scope of state responsibility.