Overview - ISO/TS 19700:2016 (steady-state tube furnace, controlled equivalence ratio)
ISO/TS 19700:2016, "Controlled equivalence ratio method for the determination of hazardous components of fire effluents - Steady‑state tube furnace (SSTF)", specifies a laboratory method to generate and analyse fire effluent under controlled decomposition conditions. The method uses a moving test specimen through a tube furnace at set temperatures and airflow rates to produce reproducible combustion products. It is validated and limited primarily to homogeneous thermoplastic materials that give consistent yields of toxicants. The document includes apparatus design, test procedure, sampling/analysis, verification (PMMA), and treatment of uncertainty and reproducibility.
Key topics and technical requirements
- Principle and apparatus: description of the SSTF, combustion boat and drive, quartz tube, calibrated thermocouples, mixing/measurement chamber and exhaust.
- Air supply and calibration: requirements for primary and secondary airflow control and calibration to define equivalence ratio.
- Test specimen preparation: specimen form, combustible loading and conditioning for thermoplastic samples.
- Selection of decomposition conditions: recommended furnace temperatures and airflow scenarios to model oxidative pyrolysis, well‑ventilated flaming, vitiated/poorly ventilated fires and post‑flashover conditions.
- Sampling and analysis: procedures for steady‑state sampling, gas and smoke aerosol analysis, mass‑loss and yield calculations.
- Validation and quality: verification using PMMA, interlaboratory reproducibility for homogeneous thermoplastics, sections on trueness, uncertainty, repeatability and reproducibility.
- Informative annexes: guidance on additional decomposition conditions, toxic potency estimation (ISO 13344), application to toxic hazard assessment (ISO 13571), bioassay use, optical density measurement and comparisons with large‑scale compartment tests (e.g., ISO 9705).
Practical applications and benefits
- Produces quantitative, reproducible data on toxicant yields (gases and smoke particulates) for fire safety engineering, material selection and toxic hazard assessment.
- Inputs for performance‑based fire models, smoke exposure and occupant risk calculations.
- Useful for product development, compliance testing, fire research and risk assessment where large‑scale testing is impractical or where controlled decomposition data are required.
Who should use ISO/TS 19700:2016
- Fire safety engineers and consultants performing fire hazard assessment and modeling.
- Test laboratories and researchers conducting small‑scale fire effluent generation and analysis.
- Material manufacturers and safety regulators evaluating thermoplastic materials for combustion toxicity.
- Organizations using data for toxic potency estimation (ISO 13344) or occupant exposure assessment (ISO 13571).
Related standards
- ISO 13344 (lethal toxic potency estimation), ISO 13571 (people exposure assessment), ISO 9705 (room/cupboard fire tests) - referenced for applying SSTF results within broader fire safety frameworks.