Types of household humidifier disinfectant and associated risk of lung injury (HDLI) in South Korea

From 2002 through 2015, hundreds of people died of fatal lung injuries associated with the use of humidifier disinfectants (HDs) in Korea. Several chemical disinfectants used for household humidifiers were later clinically confirmed to cause HD-associated lung injury (HDLI). The aim of this study is to evaluate the registered lung disease cases and to compare the distribution of HDLI patients, including deaths, by HD use characteristics including types of HD and HD brands categorized by age group. A total of 530 registered were clinically examined through two rounds of investigations conducted from July 2013 until April 2015. Information on HD use was obtained from a structured questionnaire and home investigations. Approximately one-half of the patients (n=221) were clinically confirmed to be associated with the use of HDs. Pregnant women (n=35, 16%) and pre-school children≤6years old (n=128, 58%) accounted for most of the HD-associated lung injury patients (n=163, 74%). Sixty-seven percent of HDLI patients developed HDLI after less than one year of HD use. HD products containing polyhexamethylene guanidine phosphate (PHMG) were the most frequently used among confirmed HDLI patients (n=123, 55.7%), followed by oligo (2-(2-ethoxy) ethoxyethyl guanidinium (PGH) (n=24, 10.9%) and a mixture of chloromethylisothiazolinone (CMIT) and methylisothiazolinone (MIT) (n=3, 1.4%). Other HDs did not appear to be linked to HDLI. The majority of the HDLI patients (n=85, 38.5%) was found to use only Oxy Saksak® products containing PHMG. The development of HDLI was clinically found to be associated with the use of several HD products containing PHMG and PGH, and to lesser extent, CMIT/MIT.