APPROACH TO ESTIMATING PROBABILITIES OF TRANSPORTATION-RELATED SPILLS OF HAZARDOUS MATERIALS

An approach to estimating probabilities of transportation-related spills of hazardous materials is described. The approach involves, first, determining accident rates for appropriate modes of transportation and, second, determining the fraction of accidents that result in spills. Spill probabilities are then estimated from equations based on the Poisson distribution. Estimates of spill probabilities are presently limited by the nature of the statistics. However, the Materials Transportation Bureau (Department of Transportation) is now recording more details on accidents involving spills of hazardous materials, and, therefore, more precise and meaningful estimates of spills can be obtained as this data base develops. An example is presented on how the approach may be used to estimate spills associated with chemical plant operation. However, the approach may also be used in determining probabilities of spills for whole classes of chemicals, or within certain geographical areas. Such information could be used to design more appropriate hazardous materials spill prevention, countermeasure, and control plans. © 1979, American Chemical Society. All rights reserved.