Long-term Multiple Chemical Exposure Assessment for a Thin Film Transistor Liquid Crystal Display (TFT-LCD) Industry

Ying-Fang Wang ； Shih-Min Wang ； Yu-Chieh Kuo ； Chungsik Yoon ； Ya-Fen Wang ； Perng-Jy Tsai

《Aerosol and Air Quality Research》 17卷11期 (2017/11) Pp. 2891-2900

https://doi.org/10.4209/aaqr.2017.08.0299

摘要

A surrogate approach was deployed for assessing long-term exposures of multiple chemicals at 8 selected working areas of 3 manufacturing processes located at a clean room of a thin film transistor liquid crystal display (TFT-LCD) industry. For each selected area, 6 to 12 portable photoionization detector (PID) were placed uniformly in its workplace to measure its total VOCs concentrations (C_(T-VOCs)) for 6 randomly selected workshifts. Simultaneously, one canister was placed beside one of these portable PIDs, and the collected air sample was analyzed for individual concentration (C_(VOCi)) of 107 VOCs. Predictive models were established by relating the C_(T-VOCs) to C_(VOCi) of each individual compound via simple regression analysis. The established predictive models were employed to construct a year-long C_(VOCi) databank based on the measured year-long CT-VOC for each selected area using the same portable PID. The ethanol (381 ppb-2,480 ppb), acetone (123 ppb- 624 ppb) and propylene glycol monomethyl ether acetate 29 (PGMEA; 14.4 ppb-2,241 ppb) dominated in all selected areas, and all measured C_(VOCi) were much lower than their permissible exposure limits. Predictive models obtained from simple linear regression analyses were found with an R^2 ＞ 0.453 indicating that C_(T-VOCs) were adequate for predicting C_(VOCi). The predicted year-long C_(VOCi) reveals that long-term total multiple chemical exposures of all selected areas fall to the range 0.10%-20% of the permissible exposure level. Using the C_(T-VOCs) as a surrogate for the routine checking purpose, the present study yielded allowable C_(T-VOCs) fall to the ranges of 49.1 ppm-577 ppm. Considering the approach used in the present study requires less cost and manpower, it would be applicable to similar industries for conducting long-term multiple chemical exposure assessments in the future.

關鍵字

Multiple chemical exposures ； Long-term Exposure assessment ； Risk assessment ； Clean room