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

Indices are extensively used for ranking various units of a chemical proces s industry on the I of ranking enables the professionals to identify the mo re hazardous units from the less basis of the hazards they pose of accident al 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 th e author's HIRA (hazard identification and ranking analysis, Khan and Abbas i,(1))-rank chemical process units mainly in terms of the hazardous substan ces and operating conditions associated with the concerned units. Dow and M end indices do consider some factors ('off setting index values' in the cas e 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 g reater rigour, accuracy, and precision al e needed in quantifying the impac t of safety measures on the values of the hazard indices. In this context, an attempt has been made to develop a new index, named her e the Safety Weighted Hazard Index (SWeHI). The details are presented in th is paper.