有鑑於環境保護、災害預防觀念之演進，毒性化學物質洩漏之情境及危害結果預測日益重 要，故本研究運用美國環保署開發之公開模式一有害氣體擴散模式（ALOHA)，設定不同風 速、溫度及兩種毒化物之洩漏量，探討洩漏之危害影響距離。當毒化物洩漏時，上下風位置之 洩漏濃度差距甚大，以夏季西南西風、風速1.5 m/s、30.6°C、相對溼度80%、大氣穩定度為F為 例，當二氯甲烷儲槽或丙烯腈儲槽16,020 kg全部洩漏，擴散60分鐘後，以美國緊急應變規劃 指引第二濃度（Emergency Response Planning Guidelines)也就是需避難之濃度為計算之終端濃 度，結果顯示可知，距離洩漏點下風處573 m以內超出二氯甲烷ERPG-2濃度（750 ppm)，需 有避難之規劃。而丙烯腈因其有致癌之毒性特性，ERPG-2濃度比二氯甲烷低，為35 ppm，故 距離洩漏點下風處3.9 km以內超出丙烯腈ERPG-2濃度，需有避難之規劃。本研究建議運作毒性 特性高之廠家需有更多的災害初期搶救及預防災害擴散之機制，以避免下風數公里處之居民受 到危害。

To protect the environment and prevent hazards, the leakage characteristics of toxic chemicals must be understood and predicted. This research studied the effect of a harmful leak of dichloromethane or acrylonitrile, using the areal locations of hazardous atmospheres (ALOHA). This method was designed by the USEPA to understand the leakages of various materials with various wind speeds and temperatures. The effects of a leakage of toxic chemicals upwind and downwind differ.
In this study, a simulation was performed using the following parameters; WSW wing at summer, wind-speed of 1.5 m/s, temperature of 30.61, relative humidity of 80%, an atmospheric stability of F, complete leakage of 16,020 kg dichloromethane from tanks and a dispersion time of 60 min. The results of the simulation revealed that following leakage, the concentration of dichloromethane was 750 ppm (Emergency Response Planning Guidelines, ERPG-2) at a distance of 573 m downwind of the source of the leak and it is suggested to find other place for sheltering. Moreover, acrylonitrile has been classified as a carcinogen and the ERPG-2 of acrylonitrile was 35 ppm, which is lower than that of dichloromethane. Relevant results reveal that the concentration of leaked acrylonitrile exceeded 35 ppm at a distance of 3.9 km downwind of the source of the leak. This study suggests that manufacturers that use highly toxic chemicals must have an emergency response plan and a prevention program to protect nearby residents from harm.