CMIT/MIT 가습기살균제 판결: 대법원 파기환송 결정의 환경보건학적 함의

The CMIT/MIT Humidifier Disinfectant Ruling: Environmental Health Implications of the Reversal by the Supreme Court

On December 26, 2024, the Supreme Court of Korea reversed the appellate court’s conviction of CMIT/MIT product manufacturers, citing chemical differences between PHMG products and independent development. However, both products shared identical exposure routes (inhalation), target organs (lungs), and vulnerable populations. All manufacturers failed to assess inhalation toxicity and concealed ingredients. Scientific evidence established CMIT/MIT’s pulmonary toxicity through clinical cases of severe lung injury from CMIT/MIT-only exposure, cellular toxicity studies, and epidemiological evidence of synergistic interactions with PHMG. While the appellate court integrated toxicological, epidemiological, and clinical evidence, the Supreme Court neither evaluated CMIT/MIT’s toxicity nor addressed co-exposure scenarios, effectively applying scientific uncertainty in favor of manufacturers. The ruling exposed structural limitations in the current criminal law system regarding environmental health disasters. In the remanded trial, liability for single-exposure victims should be clearly established. For the 94 co-exposure victims, the evidentiary standard is critical: If courts demand precise quantitative attribution per substance—which is scientifically infeasible due to synergistic interactions and individual variability—this may paradoxically preclude victim relief despite sufficient evidence. However, liability can be established if substantial contribution suffices. Systemic reforms including abolishing statutes of limitations for environmental crimes and expanding judicial scientific advisory systems are urgently needed.