Electronic industries in Taiwan are classified into six subcategories, included the manufacture of semiconductor, wafer, TFT-LCD, LED, transistor and mask. Depending on the characteristics and requirements of products, the manufacture processes of electronic industries are varied. However, yellow-light, lithography and etching units are the common process. In these units, various organic solvents such as photo-resist, stripper, developer, isopropyl alcohol and acetone are often used. By literature survey, it found that the authorities in most countries had managed and controlled the wasted organic solvents by the regulations related to hazardous wastes and toxic substances, and generally did not allow the direct discharge of organic solvents into wastewater treatment system and receiving water body. But, the regulations concerned about the monitoring of total toxic organics (TTO) due to the discharge of organic solvents were appeared in the effluent guidelines and standards of US EPA. In this study, the results of sampling and analysis of wastewater from more than 15 electronic plants revealed that trace amounts of chloroform, toluene, and butyl benzyl phthalate were detected, but the TTO concentrations did not exceed the limitations of pretreatment standards set up by US EPA. In addition, based on the evaluation of feasibility, the enforcement of controlling total toxic organics in the effluent of electronic industries is impractical at present in Taiwan. However, the implementation of source control of organic solvent and submitting a solvent management plan as well as discharge monitoring report to authorities is suggested.

electronic industry,total toxic organics(TTO),solvent management