| dc.description.abstract | Semiconductor factories use many kinds of organic solvents in their manufacturing processes which will cause health hazards or to the worse occupational diseases for laborers exposing themselves to this environment for long duration of time. This study aims to evaluate health risk of occupational exposure for laborers working in a wafer-surface treatment process of a semiconductor plant to realize their actual exposure pattern. The methods of chemicals exposure assessment and control measure include preliminary hazard analysis, additive effect assessment, health risk assessment, abnormal health data analysis, and chemicals management classification.
Six working groups with similar organic solvent exposure were selected as study targets. They include cleaning operation area (SEG01), electronically photolithography zone (SEG02), photo resisting area (SEG03), wet photo resisting area (SEG05), electronically grinding zone (SEG09), and wet etching zone (SEG17).
The values of additive effect regarding to chemicals exposure for laborers based on environmental monitoring data from 2010 to 2014 are as follows. The value of 0.11 for cleaning area (SEG01), 0.13 for electronically photolithography zone (SEG02), 0.20 for photo resisting area (SEG03), 0.13 for wet photo resisting area (SEG05), 0.06 for electronically grinding zone (SEG09), and 0.18 for wet etching zone (SEG17). Among various values, the value of photo resisting area (SEG03) is the highest. However, the values of additive effect in each working group are all smaller than 1 and thus they meet regulatory requirements.
According to health risk assessment, the hazard index (HI) of chronic inhalation for each group in descending order is SEG03 (1.72 * 10-1), SEG05 (1.15 * 10-1), SEG09 (1.22 * 10-3), SEG01 (8.22 * 10-4), SEG17 (6.24 * 10-4), and SEG02 (1.68 * 10-4). The computed values are all smaller than one, the allowable criterion. For laborers working in the similar area, the health hazard in the photo resisting area (SEG03) is more severe than that in the wet photo resisting area (SEG05) and the wet etching zone (SEG17) is inferior to he electronically yellow-ray zone (SEG02). The result is similar to that of additive effect.
The decending order of abnormal rate for health examination data is the photo resisting area (SEG03, 16.2%), the cleaning area (SEG01, 15.3%), the wet photo resisting area (SEG05, 11.5%), the electronically photolithography zone (SEG02, 10.9%), the wet etching zone (SEG17, 10.8%), and the electronically grinding zone (SEG09, 10.6%). For paired t-test between laborers of each working area and administrative staff on creatine and glomerular filtration rate, significant differences were found for laborers in the areas of SEG02, SEG05, SEG09, and SEG17. The hazardous materials both used in SEG02 and SEG17 were acetone, phenol and PGMEA (Propylene Glycol Monomethyl Ethyl Acetate) and the quantity of phenol was found with significant difference from the comparison.
To sum up the above assessments, SEG03 was ranked as the area with the highest risk and the causal hazardous substances were naphthalene, acetone, isopropyl alcohol, and NMP (N-Methyl-2-pyrrolidone). The health risk of SEG05 was ranked second with causal hazardous substances including naphthalene, acetone and isopropanol. The laborers in the above mentioned areas should enhance the checking frequency of machine leakage, protective equipment maintenance, safety of chemicals storage, and fault machine listing mechanism. The phenol used in SEG02 and SEG17 is probably the causing substance of creatinine abnormality of laborers in health examination. The monitoring frequency for environmental exposure of laborers in these two areas should be increased and discard manual replacement of the photoresist agent.
| en_US |