In Korea, the cause of lung disease of unknown origin was identified as humidifier disinfectants in November 2011. In February 2017, the 'Special Act on Remedy for Damage Caused by Humidifier Disinfectants' was promulgated. Even though emotional and mental injuries caused by humidifier disinfectants have been reported, the focus of the special act has been on physical injury only, and criteria for recognizing mental health impact have not been considered. This case considers emotional and mental injury caused by humidifier disinfectants. After a humidifier disinfectant was used from January 2005 to April 2006, the patient's son aged 20 months was hospitalized with respiratory symptoms, and he died within two weeks. Also, the patient was hospitalized for a month with the same symptoms, and then she led a normal life with no symptoms. After both mother and son were diagnosed with definite (level 1) humidifier disinfectant lung injury (HDLI) in 2017, she took to drinking alcohol because of extreme guilt over her son's death. In March 2018 she died from acute liver failure due to alcohol use disorder. The patient's death was caused by continuous alcoholism, due to emotional and mental trauma caused by her son's death after HDLI was revealed as the cause. The government did not acknowledge her death was due to humidifier disinfectants, but the company that sold the humidifier disinfectants recognized her as a victim and compensated the family of the victim. There are still lots of psychological responses among humidifier disinfectant disaster victims. Mental health impact on humidifier disinfectant victims should be considered more carefully, and institutional improvements should be made into establish psychological interventions and measures.