Fire and explosion risk classification using MIL-STD-882E standard and PHL and PHA techniques and analysis of a case study incident

Mina Sharifipour  M; Varshosaz  K; Orak  N; Cheraghi  M; Laal  F

doi:10.18502/tkj.v17i3.20026

Mina Sharifipour M Department of Environment, Ahv.C, Islamic Azad University Ahvaz, Iran
Varshosaz K Department of Environment, Ahv.C, Islamic Azad University Ahvaz, Iran
Orak N Department of Environment, Ahv.C, Islamic Azad University Ahvaz, Iran
Cheraghi M Department of Environment, Ahv.C, Islamic Azad University Ahvaz, Iran
Laal F Department of Occupational Health Engineering, School of Health, Determinants of Health Research Center, Birjand University of Medical Sciences, Birjand, Iran

DOI: https://doi.org/10.18502/tkj.v17i3.20026

Keywords: MIL-STD-882E, Accident analysis, Risk, Petrochemical, Preliminary Hazard Analysis (PHA)

Abstract

Introduction: Process industries are inherently associated with the risk of catastrophic events such as fires and explosions. An integrated framework was created to identify analyze, and classify fire and explosion risks utilizing Preliminary Hazard List (PHL) and Preliminary Hazard Analysis (PHA) techniques along with the MIL-STD-882E risk assessment standard.

Materials and Methods: Initially, an analysis team was established and a system description was conducted. A real fire incident in the HDPE unit of a petrochemical plant was then selected as a case study. The underlying causes were identified through operational data, expert interviews, and technical documents. Using severity and probability tables from PHL and PHA methods, along with the MIL-STD-882E risk matrix, the risk level for each scenario was determined and corrective recommendations were proposed

Results: The findings revealed that eight hazardous conditions could possibly result in fire and explosion risks. Reactor explosions and centrifuge fires were identified in the initial control level of the study, accounting for 25%, linked to technical failures in control valves (TICI4). This scenario was assigned a risk level of 1D, classified as serious per the matrix. Compiling a comprehensive list of Pressure Safety Valves (PSVs) and implementing periodic inspections could significantly reduce the associated risk level. Moreover, the predominant consequences were mainly associated with deficiencies in isolation procedures, weaknesses in permit-to-work systems, and mistakes made by individuals.

Conclusion: Control and preventive measures proportional to the identified risk levels were recommended. The results demonstrate that combining PHA and PHL techniques with the MIL-STD-882E risk classification framework can enhance safety-related decision-making and mitigate hazards in high-risk process industries.