reactiontofire

Reaction to fire is a property of materials and products that describes how they behave when exposed to heat or an ignition source. It includes how easily the material ignites (ignitability), the speed at which flames spread across its surface, the rate at which heat is released, and the quantity of smoke and toxic gases produced. These behaviors are used to assess fire hazard and to inform safety decisions in design, construction, and consumer goods.

Assessment typically relies on standardized laboratory tests and classification schemes that yield a numerical or letter grade. In Europe, Euroclass under EN 13501-1 classifies materials from A1 (non-combustible) to F (easily flammable) and uses sub-classes for smoke production (s1, s2, s3). Other regions employ different schemes and tests, such as methods for plastics (e.g., UL 94) or for furniture and building materials, measuring flame spread, heat release rate, and smoke generation.

Applications of reaction to fire ratings span building materials, interior furnishings, textiles, electronics enclosures, and transportation interiors. A product’s reaction-to-fire rating informs building codes, product labeling, and procurement decisions. It is distinct from fire resistance, which concerns a material's ability to maintain structural integrity and function during a fire for a specified period.

Limitations and context: standardized tests are designed to be repeatable and comparable, but they may not predict every real-world scenario due to differences in geometry, ventilation, and service conditions. Ongoing research seeks to improve predictive metrics and to address evolving materials and composite systems.