Experimental determination of indoor air concentration of 5-chloro-2-methylisothiazol-3(2H)-one/ 2-methylisothiazol-3(2H)-one (CMIT/MIT) emitted by the use of humidifier disinfectant

Abstract

A mixture of 5-chloro-2-methylisothiazol-3(2H)-one/2-methylisothiazol-3(2H)-one (CMIT/MIT) had been used as an active ingredient in humidifier disinfectants (HDs). Owing to its high reactivity, the atmospheric concentration of CMIT/MIT, following its use in HD, would be lower than expected assuming that it is removed by ventilation only. In order to evaluate the exposure concentration of CMIT/MIT used as an HD, room-scale chamber studies were conducted under plausible use of three different HD doses at air change rates (ACR) of 0.3, 0.5, and 1.0 h-1. Atmospheric CMIT/MIT was sampled using two serial impingers containing deionized water after the attainment of steady state. Water samples in which CMIT/MIT was dissolved were concentrated using a cosolvent evaporation method with efficiencies of 35.5 and 77.9% for CMIT and MIT, respectively. The estimated air concentration, assuming that all the CMIT/MIT is absorbed in deionized water, increased linearly with increasing emission rate, but was independent of the ACR. This indicates that the removal rate of CMIT/MIT via chemical reactions is more than the removal rate by ventilation. Further investigations on homogeneous and heterogeneous chemical reactions of CMIT/MIT under ambient conditions are necessary to understand the actual exposure concentration of the mixture in HD.

Characteristics of Exposure to Chloromethylisothiazolinone (CMIT) and Methylisothiazolinone (MIT) among Humidifier Disinfectant-Associated Lung Injury (HDLI) Patients in South Korea

“…Thirdly, our estimated airborne levels of the mixture of CMIT and MIT to which HDLI patients were exposed (Table 4) are similar to the results (CMIT: 0.95-4.37 µg/m 3 , MIT: 0.30-1.75 µg/m 3 ) reported by Park et al (2020), who measured airborne CMIT and MIT using two serial impingers in a room-sized stainless steel chamber where HD containing the intended level was used [27]. This partly supports the validity of the assumptions for exposure assessment in this study, although there might be variations in exposure parameters among patients and potential losses of CMIT and MIT other than through ventilation.…”

Spatial Uncertainty in Modeling Inhalation Exposure to Volatile Organic Compounds in Response to the Application of Consumer Spray Products

“…Changes in the ambient air concentration of test VOCs were measured in real-time using a custom-made chamber [ 18 ] ( Figure S1a ). A 30 m 3 stainless room-sized chamber was manufactured to meet the criteria set by the American Society for Testing and Materials (ASTM), and United States Environmental Protection Agency (U.S. EPA) [ 19 , 20 ].…”

A Commonly Used Biocide 2-N-octyl-4-isothiazolin-3-oneInduces Blood–Brain Barrier Dysfunction via Cellular Thiol Modification and Mitochondrial Damage

“…Although the use of antibacterial substances is increasing globally, the systemic effects of IT biocides on human health are poorly understood [ 3 , 4 , 5 , 6 ]. These biocides can be absorbed orally and dermally during personal and industrial use [ 7 , 8 , 9 ] and subsequently circulate in the blood posing a human health risk [ 2 , 10 , 11 ]. While blood vessels are continuously exposed to circulating xenobiotics, the effects of IT biocides on the vascular system remain unknown.…”