Overview - ISO 15025:2016 (Protective clothing, limited flame spread)
ISO 15025:2016 defines a laboratory test method for limited flame spread of vertically oriented flexible materials used in protective clothing. It specifies two ignition procedures - surface ignition and bottom-edge (edge) ignition - to evaluate how single- and multi-component fabrics (coated, quilted, sandwich constructions, multilayer assemblies, trims and seams) respond to a small, defined flame. The standard is intended for materials exposed to a small ignition source and is not appropriate for situations with restricted air supply, large intense heat sources, or materials showing extensive melting/shrinkage.
Key topics and technical requirements
- Two procedures: Procedure A (surface ignition) and Procedure B (bottom-edge ignition) for vertically mounted specimens.
- Specimen & apparatus: Defined specimen holder frames, templates and pin locations; templates sizes correspond to the procedure used. Burner geometry and mounting details are specified (Annex A).
- Fuel: Commercial-grade propane (≥95% purity) is the standard fuel; deviations must be recorded.
- Measured observations: melting, flame spread, afterflame time, afterglow time, formation of debris or flaming debris, holes, and optionally damaged (char) length.
- Test conditions and safety: 10 s flame application under controlled ventilation; guidance on operator safety and fume extraction is included.
- Multilayer & seam testing: Multilayer assemblies and trimming/seams can be tested as part of the fabric assembly; hem and seam preparation instructions are provided.
- Reporting: Detailed reporting requirements including test procedure used, gas type, and observed behaviours.
Applications - who uses ISO 15025:2016
- PPE manufacturers and textile product designers evaluating fabric performance against small ignition sources.
- Independent testing and certification laboratories performing flame-spread characterization for protective clothing standards and product specifications.
- Safety engineers and compliance officers selecting materials for workwear, firefighting liners, or industrial garments where limited flame spread behaviour is critical.
- Procurement and quality assurance teams who require documented, repeatable test results for supplier qualification.
Practical value & limitations
- Provides a repeatable laboratory method to classify materials that do not propagate flame to specimen edges under a short flame exposure.
- Useful for material selection, product development and compliance evidence for limited-flame-spread performance.
- Not suitable for assessing performance under oxygen-restricted conditions, intense heat fluxes, or for highly melting/shrinking materials - other test methods should be used in those cases.
Related standards
- ISO/TR 11610 (terms/definitions referenced)
- ISO 6941 and ISO 6940 (related flame test methods)
- Developed by ISO/TC 94/SC 13 (Protective clothing)
Keywords: ISO 15025:2016, protective clothing, limited flame spread, flame test, surface ignition, bottom-edge ignition, textile testing, PPE testing, propane flame test.