ISO 9239-1:2025

Overview

ISO 9239-1:2025 - Reaction to fire tests for floorings - Part 1: Determination of the burning behaviour using a radiant heat source specifies a laboratory method to assess the wind‑opposed burning behaviour and flame spread of horizontally mounted floorings exposed to a radiant heat gradient and ignited with pilot flames. The method applies to all flooring types (textile carpet, cork, wood, rubber, plastics, coatings) and reports key performance metrics such as heat flux at extinguishment (HF‑E) and critical heat flux (CHF). Annex A covers smoke measurement; Annex B gives information on test precision.

Keywords: ISO 9239-1:2025, reaction to fire tests for floorings, radiant heat source, critical heat flux, HF‑E, smoke development, flooring fire safety testing.

Key technical topics and requirements

• Purpose: evaluate wind‑opposed flame spread under a controlled radiative heat flux representative of early‑stage adjacent fires.
• Specimen mounting: horizontally mounted flooring specimens; results include the effect of any substrate, backing, adhesive or underlay used.
• Measured parameters:
  • Heat flux (kW/m²) profile across the specimen.
  • HF‑E (heat flux at extinguishment) and HF‑X (heat flux at X minutes) with CHF defined as the lower of HF‑E or HF‑30.
  • Smoke development assessment (Annex A) using light‑measuring systems or LED alternatives (ISO/TS 19850).
• Apparatus and calibration: standardized test chamber, gas‑fired radiant panel, pilot burner, heat flux meters, thermocouples, anemometer, pyrometer and recording equipment. Calibration procedures and heat flux meter calibration references are included (ISO 14934‑2/3).
• Safety and test integrity: guidance on gas/air supply safety, hazard assessment, and handling of re‑ignition events; precision data provided in Annex B.
• Reporting: required test report elements and an example report template (Annex D).

Practical applications and who uses it

ISO 9239-1:2025 is used to:

• Support product development and quality control for flooring manufacturers (carpet, resilient, engineered wood, vinyl, tiles).
• Provide data for fire safety engineers and specifiers evaluating interior finishes, especially in corridors and escape routes.
• Inform building compliance, procurement and third‑party testing laboratories performing reaction‑to‑fire tests. Note: test results reflect laboratory behaviour and cannot alone define actual fire risk; installation details (backing, adhesive, substrate) can materially affect outcomes.

Related standards

• ISO 13943 - Fire safety vocabulary
• ISO 554 - Conditioning atmospheres
• ISO 14934‑2/3 - Calibration of heat flux meters
• ISO/TS 19850 - Use of LED for smoke measurement
• EN 13238 - Conditioning and substrate selection guidance
• ISO 14697 - Guidance on choice of substrates

Use ISO 9239-1:2025 when you need standardized, comparable metrics (HF‑E, CHF, smoke data) to assess and document flooring reaction to fire under radiant‑heat, wind‑opposed conditions.