Dow chemical exposure index

Tools are available to assist in comparing the risk associated with two or more different processes. For example, the first sheet of the Dow Fire and Explosion Index (FEI) (Dow, 1994b) ranks the safety characteristics of the process from a fire/explosion standpoint, without taking credit for protective and mitigation features. The Dow Chemical Exposure Index (CEI) (Dow, 1994a) and Id s Mond Index (ICI, 1985 Tyler, 1985) are other ranking tools. 

Dow-Chemical Exposure Index (CEI)3, which are two popular forms of hazards survey. These are formal systematized approaches using a rating form, similar to an income tax form. The final rating number provides a relative ranking of the hazard. The F EI also contains a mechanism for estimating the dollar loss in the event of an accident. 

Figure 10-6 Form used for the Dow Chemical Exposure Index. Source Dow s Chemical Exposure Index Guide (New York American Institute of Chemical Engineers, 1994). Reproduced by permission of the American Institute of Chemical Engineers.

Dow Chemical Exposure Index, 13 156 Dow Fire and Explosion Index,... 

Inventory of hazardous material in pipes can also be minimized by using the hazardous material as a gas rather than as a liquid. The Dow Chemical Exposure Index (14) is a tool that can be used to measure inherent safety with regard to potential toxic exposure risk. Table 2 shows the reduction in the Chemical Exposure Index that can be realized by handling a number of hazardous materials as a gas rather than as a liquid, assuming that the same-size pipe can deliver the required flow rate. Figure 6 shows the decrease in the hazard zone (toxic cloud footprint) that resulted from relocating a chlorine vaporizer from a production building to... 

The Dow Fire and Explosion Index (FEI) (12) and the Dow Chemical Exposure Index (CEI) (14) are two commonly used tools that measure inherent safety characteristics. Gowland (25) reports on the use of the FEI and CEI in the development of safety improvements for a urethane plant. Tables 1 and 2 illustrate the application of the FEI and CEI in measuring inherent safety characteristics of process design options. These indices measure the inherent safety characteristics of processes in only two specific areas—fire and explosion hazards and acute chemical inhalation toxicity hazards. Other indices would be required to evaluate other types of hazards. 

Several risk indices have been practiced by the chemical and manufacturing industries over the past 50 years (see Table 8.5) (Heikkila, 1999). The important ones among these indices are the Dow Fire and Explosion Index, the Dow Chemical Exposure Index, the HAZAN (Hazard Analysis), and the Prototype Index of Inherent Safety. 

The Dow Fire and Explosion Index (FEI) (Dow, 1994 Van den Braken, 2002) and the Dow Chemical Exposure Index (CEI) have been developed and practiced hy Dow Chemicals for several decades. These tools measure process inherent safety characteristics, help to quantify the expected damage of potential fire and explosion incidents, and identify equipment that would likely contribute to the creation of the incident. The Mond Index was developed by ICI (UK) from the Dow Fire and Explosion Index. The Mond Index includes toxicity and covers a wider range of processes and storage installations than the FEI. The various aspects considered in the FEI are material factor (flammability and reactivity), general process hazards such as exothermic/endothermic reactions, and special process hazards such as toxic nature of the chemicals and dust explosion. For example. Table 8.6 shows the results of the FEI for various inventory levels of storage of ethyl acrylate. 

One approach is to assume a constant liquid thickness throughout the pool. The pool area is then determined directly from the total volume of material. The Dow Chemical Exposure Index (AIChE, 1994) uses a constant pool depth of 1 cm. 

A Dow risk analysis package consists of the analyses developed with the Dow F EI and the Dow Chemical Exposure Index plus reports of loss prevention measures. This risk analysis package is used by industrial insurance carriers to predict the likelihood and size of loss from catastrophic events. 

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