;During the process of the metal surface cleaning, chemicals can be emitted to the air of the workplace and may be absorbed by the body through the skin. Exposure to harmful chemicals is known to cause hazards to the health of the workers. The studied site of this thesis has implemented a program of environmental monitoring of existing on-site hazardous materials, in which the contracting environmental analytical lab has run tests on the concentrations of regulated hazardous substances and the results by far have met the permissible standards. However, these results have not served as a reference for operation improvement, nor has been the environmental monitoring data properly managed over the past years. It does not reflect the actual situation.
Hence, in this study we looked into the environmental monitoring data of five often-used chemicals, including nitric acid, hydrochloric acid, acetone, hydrofluoric acid and potassium hydroxide, in different chemical surface cleaning areas, such as Semiconductor Cleaning Area, Photoelectric Cleaning Area, Dissolving Gold with Chlorazoic Acid Area, and Metal Finishing Area. More than three measurements and evaluation methods, such as ILO-CCB, Quantitative Estimation, and Statistical Analysis were used to predict the result. We combined the actual environmental assessment value to evaluate the occupational exposure hazard and health risk on employees who handle chemicals in works (Chemical Department). In order to implement chemical risk grading management and to handle exposure patterns chronically, a health risk management strategy was proposed according to the health risks assessment results. As for the chemical exposure analysis and strategy methods, they include primary hazard analysis, additive effect assessment, health risk analysis, abnormal health checkup, and chemical grading management.
According to the results using the modified analogy method to classify the chemicals as well as the semi-quantitative method to assess the risk level, it was found that the risk grades were at level 3 or 4. The results indicated that although the currently used chemical concentrations meet the statutory permissible, they are still classified as moderate to high-risk chemicals. It is necessary to take improvement measures, for example, implement engineering control or enhance inspection points for operating procedures and methods. Other improvements can be equipment operation, maintenance, supervision, self-inspection, and so on. The semi-quantitative assessment results can also be used as a reference for the next operational environmental monitoring. The risk results of the quantitative non-ventilation estimation were at level 2, indicating that this can just be the routine checkup. Statistical analysis was used to evaluate chemicals with permissible concentration. In the semiconductor cleaning area, the risk level of nitric acid was at level 3, a moderate to high risk. It is recommended to be managed firstly and should be monitored and measured every three months. As for other chemicals with level 3 risks, it is recommended to provide personal protective equipment for operators, conduct self-health risk management, propose risk reduction control measures and continue the monitoring.
The chemical hazard rate of this site was assessed by the additive effect, and the result showed the risk level is less than 1, which is within the environmental monitoring acceptable limit. When examining the blood checkup results of Chemical Department employees, there was no visible abnormality in their white blood cells and red blood cells. It was inferred that the chemical department employees were not affected directly from the chemical exposure workplace. However, from the other health checkup data, it was found that employees’ liver function and cholesterol were classified as level 2 and 3 in health management. To fully achieve the purpose of occupational safety protection and to avoid the occupational hazard, there are several measures to take. For example, promote employees’ health care service, strength the awareness of employees’ health risk assessment and health management, promote workplace health management activities, such as adaptive operator selection, follow-up on employees’ abnormal health checkup cases, and so on.