标题：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
出版社：Korean Society of Environmental Health and Toxicology
摘要：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.
关键词：biocides;chemical reactions;chloromethyl/methyl-isothiazolinone (CMIT/MIT);health risk assessment;indoor air
