Study the particle size distribution of the different type manufacturing processes in the indium-tin oxide plant

• Main Authors: Szu-Chieh Wang, 王思捷
• Other Authors: Hung-Hsin Liu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/63652336171668150801

碩士 === 中山醫學大學 === 職業安全衛生學系碩士班 === 102 === Abstract From animal experiments and human cases report, inhalation of indium tin oxide (ITO) has adverse influence on human health such as bronchioloalveolar carcinoma, pulmonary adenomatosis, squamous cell carcinoma, pulmonary alveolar proteinosis, pulmonary fibrosis, macrophage infiltration. Also, ITO particles sized as the ultrafine particles (UFP less than 1μm) are more easily breathe into the lung with a bigger surface area relative to those larger particles to induce more lung diseases due to the characteristic of ITO particles difficultly dissolved in the lung. There is little research of indium tin oxide in Taiwan. The purpose of this study was to study the indium tin oxide particle size distribution in the different working type from various plants. The Marple 8-stage cascade impactors were used for area monitoring and IOM was used for personal sampling to collect samples. The Marple sampler consists of eight impaction stages（50% cut-off dae = 0.52, 0.96, 1.55, 3.5, 6.0, 9.8, 14.8, and 21.3 μm, respectively）and a back-up filter (34mm PVC with 0.5μm pore size). The IOM personal sampler was used the 25 mm MCE filter paper with 5μm pore size. The Sigma Plot and SPSS software package was used for data process and statistical analysis. The results showed that the particle size distribution at the peak d50 was at 0.96μm from both the ITO target and display panel plants. The particle size as the UFP can easily cause lung damages if using a larger number abrasive paper to generate such smaller particle size dust. The dust concentrations were collected by IOM from different tools for polishing ITO target in display panel factories. The belt sander generated the highest particle concentration (26.144 mg/m3), followed by the disc sander produced concentration (7.672 and 9.722 mg/m3), and the abrasive papers generated the lowest particle concentrations (5.307, 15.211, and 5.824 mg/m3). One workplace had high concentration (15.211 mg/m3) because plastic shield was used to surrounding the ITO target area for polishing. There is no difference between the total dust concentration and respirable dust concentration in the target plants. The result showed the respiable dust is the main composition among the target plants. A particle concentration of polishing areas in target plants can reach to the highest as 3.782 mg/m3. It should be noticed that the particle sizes in bonding area is nanometer-scaled and below the IOM limitation. In this study, we found that there are more than 80% the particle size distribution is in the trachea-bronchial region and pulmonary region from both ITO target and display panel plants. Even more than 50% the particle size is in the pulmonary region. It means that the dust will be breathed into the pulmonary alveolus easily. We strongly suggest that an appropriate management plan should be implemented for indium exposure workers. These include adequate usage of Powered Air-purifying Particulate Respirators（PAPR）and good engineering control strategies for indium exposure workers. Key words：indium-tin oxide (ITO) ‧Marple‧particle size‧Powered Air-purifying Particulate Respirators