Wildfire Natech accidents in the wildland-industrial interface: Exposure pathways analysis

• Wildfire Natech risk assessments lack an established hazard assessment methodology. • Wildfire analyses need to include flame, firebrand, and fire environment exposure. • A Fault Tree Analysis considering all wildfire hazards is proposed. • Specific missing models for failure probability estimation are highlighted. Wildfires are growing more intense, and wildfire-induced industrial accidents and near-misses are increasing. These trends demand dedicated quantitative risk analysis (QRA) for wildfire Natech accidents. This paper assessed wildfire exposure pathways to industrial components through input from two international stakeholder workshops and a fault tree analysis (FTA); the FTA highlights missing models and data to estimate wildfire induced industrial failure. Establishing a wildfire Natech QRA methodology requires wildfire hazard metric models and critical industrial components response tests to the most likely hazard mechanisms. Considering four exposure mechanisms (flame radiation, flame contact, firebrand exposure, and the fire environment), the FTA identifies 30 basic or underdeveloped events that shape impact pathways in chemical industries. The identified events directly indicate the missing models and investigations required to formalise wildfire Natech risk assessments. A case study illustrates the FTA for two industrial components, estimating the fire probability of an external floating roof tank and the loss of containment probability for plastic intermediate bulk containers exposed to normal and extreme wildfire conditions.