Fire resistance is an important factor when selecting FRP grating for industrial and infrastructure projects. Although FRP (Fiberglass Reinforced Plastic) grating offers excellent corrosion resistance and durability, its fire performance depends on resin formulation and compliance with recognized fire resistance standards. Different regions and industries apply different testing methods.
ASTM E84 / UL 723 – Flame Spread and Smoke Development
ASTM E84, also known as UL 723, is one of the most widely used fire standards for FRP grating. This test measures the Flame Spread Index (FSI) and Smoke Developed Index (SDI).
FRP grating that meets Class 1 (Class A) requirements typically has an FSI of 25 or less and an SDI of 450 or less. This classification is commonly required for industrial facilities, public areas, and offshore platforms.
ASTM D635 – Horizontal Burning Rate
ASTM D635 evaluates how quickly a plastic material burns when exposed to flame. FRP grating that passes this test is often described as self-extinguishing, meaning the flame stops once the ignition source is removed.
This standard is frequently used as a supplementary reference for industrial flooring and structural components.
EN 13501-1 – European Fire Classification
In European markets, EN 13501-1 is the primary fire classification system. It evaluates a material’s reaction to fire, smoke production, and flaming droplets.
FRP grating may be classified with ratings such as Bfl-s1 or Cfl-s1, depending on resin type and performance level. These ratings are often required for commercial buildings and infrastructure projects in Europe.
ISO 5660 and ASTM E662 – Heat Release and Smoke Density
ISO 5660 (Cone Calorimeter Test) measures heat release rate and smoke generation, providing detailed fire behavior data.
ASTM E662 focuses on smoke density, which is critical in enclosed or evacuation-sensitive areas.
Phenolic resin FRP grating typically performs best in these tests due to low smoke emission.
Conclusion
FRP grating fire resistance is evaluated through standards such as ASTM E84, ASTM D635, EN 13501-1, ISO 5660, and ASTM E662. Selecting the right resin system and fire classification ensures compliance, safety, and long-term performance in demanding environments.
