How to Evaluate the Fire Performance of Materials? Are You Familiar with International Fire Standards?

How to Evaluate the Fire Performance of Materials? Are You Familiar with International Fire Standards?

With the evolution of times, buildings are now subject to more diverse requirements, and many new materials have emerged as a result. Among these, a significant number have made outstanding contributions to architectural innovation. However, with the increasing variety of building materials, safety performance remains the top priority. Thus, the fire resistance of building materials is a critical aspect of evaluating their performance.

Different countries and regions have their own testing standards. Evaluating the fire performance of materials is not based on a single indicator but is a multi-dimensional, systematic scientific process. It primarily involves simulating the harsh conditions of different stages of a fire and conducting a series of standardized tests on materials to comprehensively assess their behavior in fire scenarios. The main evaluation dimensions include:

1. ​​Non-combustibility:​​ Whether the material does not burn at all under high temperatures. This represents the highest level of fire performance.
2. ​​Heat Release:​​ The rate and total amount of heat released when the material burns. The heat release rate is the most critical factor driving fire development.
3. ​​Flame Spread:​​ The speed at which flames spread across the surface of the material.
4. ​​Smoke Production:​​ The amount and density of smoke generated when the material burns. Smoke is one of the leading causes of casualties in fires.
5. ​​Flaming Droplets/Particles:​​ Whether the material produces droplets or particles during combustion that can ignite other objects.
6. ​​Fire Resistance:​​ Refers primarily to the shortest time a building component (such as walls, floors, or load-bearing columns) can maintain its stability, integrity, and thermal insulation under standard fire conditions. This is a performance indicator more focused on overall components.

Internationally common fire standards include the following:

1. ​​International Organization for Standardization (ISO) Standards:​​
   ISO standards are often used as globally applicable fundamental testing methods and are referenced by many national and regional standards.

   • ​​ISO 1182:​​ Non-combustibility test. A fundamental standard for determining whether a material is non-combustible.
   • ​​ISO 1716:​​ Determination of calorific value. Evaluates the potential fire load by measuring the total heat released after complete combustion of the material.
   • ​​ISO 5660-1 (Cone Calorimeter Test):​​ A core method for assessing fire hazard. Under controlled radiant conditions, it precisely measures key parameters such as heat release rate, total heat release, ignition time, and smoke production rate to predict the material's behavior in actual fires.
   • ​​ISO 11925-2:​​ Flammability test. Uses a small flame to directly impact the surface of the sample to evaluate the material's flammability and flame spread capability when exposed to a single ignition source.

2. ​​European Standards (EN):​​

   • ​​EN 13501-1:​​ Classification standard for the fire performance of building products and components. This is the most core and widely used classification system in the EU. It integrates multiple ISO tests to form a comprehensive evaluation matrix. Its classifications include:
     • Main classes: A1, A2 (non-combustible), B, C, D, E, F (flammable).
     • Additional classes:
       • Smoke production: s1 (low), s2 (medium), s3 (high).
       • Flaming droplets/particles: d0 (none), d1 (slow/limited), d2 (rapid/sustained).
         A material's complete European fire rating might be, for example, A-s1, d0, meaning "non-combustible material, low smoke production, no flaming droplets."
   • ​​EN 13823 (Single Burning Item Test - SBI):​​ Simulates a room fire scenario to evaluate the material's comprehensive fire performance under medium-scale fire conditions.

3. ​​American Standards (ASTM/UL):​​

   • ​​ASTM E84 / UL 723 (Steiner Tunnel Test):​​ The material is installed at the top of a tunnel furnace to observe the speed of flame spread across its surface and the amount of smoke produced. Two key indices are derived:
     • Flame Spread Index (FSI): Materials are classified into Classes A, B, and C based on FSI values.
     • Smoke Density Index (SDI).
   • ​​UL 94:​​ Standard for flame retardancy of plastic materials. Primarily used for plastic components in electrical equipment and other fields. V-0 is the highest flame retardancy rating.
   • ​​ASTM E662:​​ Smoke density test. Measures the density of smoke produced by material combustion in a specific enclosed space.

4. ​​Chinese Standards (GB):​​

   • ​​GB 8624-2012:​​ China's core standard for the classification of combustion performance of building materials and products. Its classification system is similar to the European EN 13501-1 but with slight differences. It is divided into:
     • Class A (non-combustible materials): Further subdivided into A1 and A2.
     • Class B1 (flame-retardant materials).
     • Class B2 (combustible materials).
     • Class B3 (flammable materials).
   • ​​GB/T 2408-2008:​​ Similar to UL 94, it is a testing method standard for the combustion performance of plastics.

Modern fire standards are becoming increasingly comprehensive. They not only focus on whether materials burn but also place great emphasis on secondary hazards such as smoke toxicity and flaming droplets. The evaluation systems are more scientific and holistic, helping to better prevent the significant personal and property damage caused by fires.