Rapid definition and communication of ground level toxic corridors during an environmental crisis are paramount concerns to protect public health and safety during an accident involving hazardous materials. Changing meteorological conditions, definition of dynamic stability conditions, and rapid identification of source strength have profound effects on the definition of horizontal and vertical transport of toxic materials released during a transportation or industrial accident. The pragmatic application of toxic corridor projection models during an agricultural chemical warehouse fire, a derailment involving the release of chloroform, and a tractor-trailer accident resulting in the release of ethyl chloroformate is reviewed.

The purpose of this paper is to provide information to assist those charged with the responsibility of rapidly assessing ground-level toxic corridors resulting from hazardous material accidents in industry and transportation. Three case histories are presented to demonstrate the application of toxic corridor projections for (a) a tractor-trailer accident resulting in the release of ethyl chloroformate,(b) a railroad derailment resulting in the discharge of chloroform, and (c) an agricultural chemical warehouse fire resulting in the release of toxic air pollutants.