關鍵字：有害物、暴露評估、作業環境監測、化學品分級管理、飽和蒸氣壓模式。;Assessment of Exposure to Hazardous Substances of LCD Process
- a Case Study of Manufacturer A
The development of LCD makes our life more convenient and interesting, so that information can be spread quickly. The manufacturing process uses many kinds and large amounts of chemicals, some of which are hazardous substances. Improper exposure to hazardous substances in the working environment will affect labors’ safety and health. To prevent occupational injuries, this study aims at a LCD manufacturer (represented by manufacturer A) which implements regular working environment monitoring to assess chemical exposure. However, this way fails to assess all hazardous substances and some hazardous substances may cause problems of safety, health and cost without objective assessment. This study proposes risk-oriented exposure assessment methods including chemical control banding and saturated vapor pressure mode to assess labors’ exposure and health situation, and to complement management of hazardous substances which lack monitoring methods. First, we use hazard identification to understand the safety information of hazardous substances used in factory and the possible hazards to labors exposed to hazardous environment, and then, use the three exposure assessment methods (working environment monitoring, chemical control banding and saturation vapor pressure model) to assess the risk of hazardous substances. The result of working environment monitoring shows that the monitored value of a single hazardous substance is far below the permissible exposure limits and the calculated additive effect of hazardous substances in cleanroom is also less than 1, which conforms with the regulatory requirements. The result of working environment monitoring shows that under current management the contents of Indium, isopropyl alcohol and acetone are not within the expected concentration range, and it is associated with the usage amount and the improved measures. Result of risk-oriented exposure assessment shows that current methods of hazardous substances management adopted for module process can’t meet the requirement, so the risk acceptance still need to be improved. Comparing the results of various exposure assessment methods, we understand chemical control banding may be applied to substitute the working environment monitoring, and the management methods of hazardous substances assessment by saturation vapor pressure model is at a lower level which can effectively control the concentration of hazardous substances and is suitable for noncarcinogenic substances management. Examining the regulation of protective equipment usage, we find that the use of protective equipment is insufficient when exposing to hazardous substances directly. We should strengthen the education training program of hazard communication to further reduce the workers’ risk.
Keywords: hazardous substances, exposure assessment, working environment monitoring, chemical control banding, saturation vapor pressure model.