The escalating frequency of cyberattack incidents targeting critical infrastructure, including chemical manufacturing plants, in recent years underscores the urgent need to integrate cybersecurity considerations into conventional risk analysis frameworks. To safeguard public health and the environment from potential hazards, this research proposes a comprehensive approach for assessing the cyber-physical risks within an Air Separation Unit (ASU) resulting from cyber intrusions targeting control systems. This research encompasses a detailed risk analysis, coupled with an overview of potential countermeasures essential for formulating an effective emergency response plan. To provide concrete insights, a case study involving an ASU and its associated storage facility is presented. This study defines an abnormal event as a deviation from normal plant operation arising from either process accidents or deliberate cybersecurity threats. The primary objectives of this work are to elucidate the specific hazards confronting ASU plants and to derive valuable lessons from historical incidents. Furthermore, the significant risk associated with a large-capacity ASU storage facility (exceeding 100,000 gallons of liquid oxygen) is highlighted, emphasizing its potential to trigger cascading failures and extensive damage, including environmental impact and fatalities, in the event of an abnormal occurrence. The findings of this research contribute to a more robust understanding of cyber-physical risks in critical chemical infrastructure and provide a foundation for developing strategically planned and effective emergency response strategies.
