Fire Testing and Hazard Assessment for Flame Retardant Polymer Composites

ABSTRACT Flame‐retardant polymer composites are widely used in engineering products, but their safety evaluation remains challenging because an improved result in a small‐scale flammability test does not necessarily indicate a lower overall fire hazard. This review clarifies the relationship between fire‐test methods, evaluation indicators, and application scenarios for flame‐retardant polymer composites. Screening tests, bench‐scale calorimetry, smoke and toxic‐effluent measurements, and intermediate‐ or large‐scale tests are compared according to the evidence they provide for ignition/early flaming, fire growth, smoke obscuration, toxic exposure, and assembly‐level behavior. The limitations of single‐parameter metrics, including UL‐94 classification and limiting oxygen index, are emphasized. The review further discusses how multi‐scale test outputs can be translated into an integrated scenario‐aware evidence framework, supported by multi‐criteria decision analysis and data‐driven tools when the boundary conditions are clearly defined. Future work should connect standardized fire testing, product‐specific requirements, toxicity assessment, and practical implementation so that flame‐retardant materials can be evaluated in terms of realistic fire safety rather than isolated flammability improvement.