Comparison of methods of hazard identification at plant level

Abstract Plant level hazard identification methods (Dow index and Mond index) have been evaluated by analysis of three different chemical plants (a reforming plant, a fine chemicals plant and a fertilizer plant). The results showed good agreement between the hazard rankings found by use of the Dow and Mond indices, respectively. However, some discrepancies were found, e.g. with respect to hazard ranking of gaseous hydrogen. One important limitation of the Dow and Mond indices is the lack of toxicological assessment of the involved chemical substances that were found to cause an incorrect hazard ranking when a toxic substance such as NH 3 is handled. A number of improvements to the methods are suggested.