The Single Burning Item (SBI) test is a widely used fire performance assessment method designed to evaluate the reaction to fire of building products and materials. It is commonly applied to construction products used in walls, ceilings, insulation, cladding systems, and other interior or exterior applications. The purpose of the test is to determine how a material behaves when exposed to a small ignition source and how it contributes to fire growth, flame spread, smoke production, and heat release.In the SBI test, two test specimens are mounted together in a corner configuration, forming a right angle. This arrangement simulates a realistic installation condition and helps assess how the product would perform in an actual building scenario. A single gas burner is placed at the bottom corner between the two specimens and is ignited to create a controlled fire exposure. The burner provides a fixed thermal input, which allows consistent and repeatable testing of different materials under the same conditions.During the test, several fire-related parameters are measured. One of the most important is the rate of heat release, which indicates how much energy the material contributes to the fire over time. Another key parameter is flame spread, which shows how quickly flames move along the surface of the product. Smoke production is also monitored, since smoke can significantly affect occupant safety and visibility during a fire. In addition, observations are made regarding burning droplets or particles, which can present further fire hazards if they ignite materials below.The test usually lasts for a set period, during which the specimen is exposed to the burner and then allowed to continue burning or smoldering if applicable. Sensors and measurement equipment collect data throughout the process, including exhaust gas analysis and temperature changes. These results are then used to classify the fire performance of the product according to relevant standards. Such classifications help architects, engineers, and regulators understand whether the material is suitable for use in specific building applications.One advantage of the SBI test is that it provides a practical simulation of a real fire scenario without requiring a full-scale building fire experiment. It offers a balance between laboratory control and realistic conditions. Because of this, it is often used in product certification, quality control, research, and regulatory compliance. The test is especially valuable for comparing materials and identifying those that may contribute less to fire development.Overall, the Single Burning Item test is an important tool in fire safety engineering. It provides essential information about a product’s behavior under fire exposure and supports safer material selection in the construction industry. By measuring heat release, flame spread, smoke generation, and other critical factors, the SBI test helps improve building safety and reduce fire risks.