Petrochemical Process Safety: A Comprehensive Review of Hazard Identification, Risk Assessment, and Emerging Safety Technologies

The petrochemical industry underpins modern civilization by supplying the feedstocks for plastics, fertilisers, fuels, and specialty chemicals, yet it simultaneously concentrates some of the most formidable process safety hazards known to engineering. This review synthesises six decades of scholarship, industrial experience, and regulatory evolution to present a holistic account of petrochemical process safety. We examine the physicochemical nature of major hazard sources—including vapour cloud explosions (VCEs), boiling liquid expanding vapour explosions (BLEVEs), toxic dispersion, and runaway reactions—and trace their contribution to landmark disasters such as Flixborough (1974), Bhopal (1984), Piper Alpha (1988), Texas City (2005), and Tianjin (2015). The review critically appraises established hazard identification methods (HAZOP, FMEA, What-If analysis, and Failure Mode and Effect Analysis), quantitative risk assessment (QRA) frameworks, and Layer of Protection Analysis (LOPA). Process Safety Management (PSM) systems are evaluated against the OSHA 29 CFR 1910.119 standard and the Center for Chemical Process Safety (CCPS) Risk-Based Process Safety (RBPS) framework. Emerging and disruptive technologies—artificial intelligence, digital twin modelling, Industry 4.0 integration, and drone-assisted inspection—are assessed for their potential to transform safety practice. Inherently Safer Design (ISD) philosophies and Safety Instrumented Systems (SIS) compliant with IEC 61511 are discussed in depth. The paper concludes with a forward-looking discussion of persistent challenges, including ageing infrastructure, cybersecurity threats to industrial control systems, climate-change-induced hazard escalation, and the imperative for a genuine safety culture. Together, the evidence compiled in this review points to a future in which data-driven, proactive safety architectures replace the historically reactive paradigm that has governed industry practice.