The purpose of this study is to validate and verify a head nose exposure inhalation system for nano particle inhalation toxicity studies. Carbon nano tube(CNT) particles were generated by a chemical vapor deposition(CVD) generator. And purchased single wall carbon nanotubes(SWCNT) and multi wall carbon nanotubes(MWCNT) were generated by an atomizer. CNT particle distribution was measured by Scanning Nano-Particle Spectrometer(SNPS) and Condensation Particle Counter(CPC). Diameter and length of MWCNT generated by CVD were 10~40 nm and 220~20 μm respectively. Particle number concentration of MWCNT generated by CVD were 1.3×105, 4.1×104, 5.6×103#/cc in high, middle, low chamber respectively. Distribution of particles which were less than 100 nm was 45%. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 8.5×106, 5.3×105, 1.1×104#/cc and after sonication 6.7×106, 4.1×105, 9.5×103#/cc in high, middle, low chambers respectively. Particle number concentration of SWCNT generated by atomizer after magnetic stirring were 6.7×106, 4.6×105, 8.6×103#/cc and after sonication 7.7×106, 5.1×105, 1.3×104#/cc in high, middle, low chambers respectively. We set up head nose exposure inhalation system to conduct a study on nano particle inhalation toxicity. There were sufficient particle number concentrations of nano particles generated in each chamber.

The purpose of this study is to investigate information on performance of ventilation in high-tech microelectronicscleanrooms using computational fluid dynamics (CFD). One liquid crystal display (LCD) company was examinedfor evaluating the relationship between workplace concentration and ventilation rate efficiency by using CFDsoftware, Airpak 3.0v. Acetone concentration in cleanroom for final packing process, which is inspected LCD was40.1ppm (GSD 1.91) (n=55) as geometric mean, ranged 7.8~128.7ppm and weakly correlated with ventilationrate efficiency (R²=0.37, p<0.01). Resulting from computational fluid dynamics (CFD), acetone concentrationcan be reduced 62% when install booth type local exhaust system, the most efficient way among 10 other differentventilation methods like increasing volume of general ventilation, changing the location of workers, supply orexhaust diffusers and install downstream type local exhaust system, etc. We found that volitile organic compoundsin cleanroom can be a matter of adverse health effects and the concentration was correlated with ventilation rateefficiency. The most optimized plan to control the contaminants in solvent cleaning work in cleanroom was boothtype local exhaust system.