ISO 5658-2:2006

Overview

ISO 5658-2:2006 - "Reaction to fire tests - Spread of flame - Part 2: Lateral spread on building and transport products in vertical configuration" - specifies a laboratory test method for measuring the lateral spread of flame across the exposed surface of vertically oriented specimens. The standard is intended for essentially flat materials, composites and assemblies used as wall finishes and exposed surfaces in buildings and transport vehicles (ships, trains), and for certain profiled products under specified mounting conditions. Tests expose specimens to a defined radiant heat flux with a nearby pilot flame, and record ignition, flame-front progression and extinguishment. ISO 5658-2 is a comparative, controlled method and is not, by itself, a complete assessment of real fire risk.

Key Topics and Requirements

• Test principle: vertical specimen adjacent to a gas-fired radiant panel; pilot flame ignites volatiles; track lateral flame front versus time.
• Measured outputs: time to ignition, flame spread distance vs. time, flame-front velocity, critical heat flux at extinguishment, and average heat for sustained burning.
• Specimen criteria: representative samples (flat surfaces, composites, assemblies); conditioning and preparation requirements prior to testing.
• Apparatus & instrumentation: radiant panel and support framework, specimen holder, pilot burner (propane impinging mode), heat-flux meter, total-radiation pyrometer, recorders and timing devices, backing boards and calibration boards.
• Test environment & calibration: defined irradiance fields, calibration procedures, verification and pilot flame adjustment to ensure repeatability.
• Reporting & safety: standardized test report items; safety precautions for toxic gases; annexes cover specimen construction, calibration guidance, result variability and a normative method for plastic piping.

Applications and Users

• Who uses it: product manufacturers, fire-test laboratories, materials researchers, regulatory authorities and compliance teams working on wall coverings, interior panels, laminates and transport interior materials.
• Practical uses: comparative performance ranking of surface materials; R&D and quality control for flame-retardant treatments; supporting product development and specification decisions for building and transport interiors.
• Limitations: intended for controlled comparative testing under radiative heat and pilot flame conditions - not a standalone predictor of performance in full-scale or real fire scenarios.

Related Standards

• ISO 5658 (other parts) - Part 1 (guidance/TS), Part 4 (intermediate-scale vertical test)
• ISO 13943 (fire safety vocabulary)
• ISO/TR 3814 (reaction-to-fire test methodology)
• ISO 1716 (reference for non-combustible backing boards)

Keywords: ISO 5658-2, lateral spread of flame, reaction to fire tests, vertical configuration, radiant heat flux, flame spread test, building materials, transport products, fire testing method, fire safety standards.