'Humidifier Disinfectant Ingredients' Cause Pulmonary Fibrosis

Safety Evaluation Research Institute Announces Animal Testing Results
Major Components CMIT·MIT Concluded to Cause Pulmonary Fibrosis
Findings Likely to Be Used in Trials Indicating Potential Human Impact

On the 31st, the Citizens' Center for Environmental Health and families affected by humidifier disinfectants held a press conference marking the 9th anniversary of the humidifier disinfectant disaster at Gwanghwamun Square, Jongno-gu, Seoul. Photo by Jinhyung Kang aymsdream@

[Asia Economy Reporter Hwang Junho] Animal experiments have shown that chloromethylisothiazolinone and methylisothiazolinone (CMIT·MIT), ingredients in humidifier disinfectants, cause lung fibrosis, a condition where the lungs harden.

Dr. Lee Kyuhong's research team at the Safety Evaluation Research Institute, which assesses the toxicity of substances, reported on June 16 that after repeatedly administering CMIT·MIT intratracheally to mice (C57BL/6) and observing lung injury markers, the results were published on the 12th in the international journal Molecules. CMIT·MIT are inhalation toxic ingredients in "Humidifier Mate," manufactured by SK Chemicals and Aekyung.

This study is the first to clarify the causal relationship between respiratory exposure to CMIT·MIT and pulmonary fibrosis since the humidifier disinfectant incident. The research team found that exposure to these substances in the respiratory system of animals induces lung fibrosis. The experiments showed significant changes such as increased lung weight and elevated levels of inflammatory cytokines.

The institute stated, "This paper confirms the toxicity of humidifier disinfectants through animal studies and reveals that they can cause lung fibrosis," adding, "This implies that similar problems could occur when humans are exposed."

Meanwhile, this research is expected to become a key issue in the humidifier disinfectant case that occurred in 2012. The trial for the case is scheduled for the 27th.