Safety weighted hazard index (SWeHI) - A new, user-friendly tool for swift yet comprehensive hazard identification and safety evaluation in chemical process industries

Indices are extensively used for ranking various units of a chemical process industry on the I of ranking enables the professionals to identify the more hazardous units from the less basis of the hazards they pose of accidental fires, explosions and/or toxic release. This type hazardous ones so that greater attention can be paid to the former. The available indices-including the well-known Dow and Mend indices, and the author's HIRA (hazard identification and ranking analysis, Khan and Abbasi,(1))-rank chemical process units mainly in terms of the hazardous substances and operating conditions associated with the concerned units. Dow and Mend indices do consider some factors ('off setting index values' in the case of the Mend index and 'credits factor ' in the case of the Dow index) to account for the safety measures existing or planned in the unit, but much greater rigour, accuracy, and precision al e needed in quantifying the impact of safety measures on the values of the hazard indices. In this context, an attempt has been made to develop a new index, named here the Safety Weighted Hazard Index (SWeHI). The details are presented in this paper.