Material Flammability Characterization

Summary

The Material Flammability Characterization project is developing a database (the NIST Material Flammability Database) to maintain the tools (experimental and analytical) needed to enable quantitative prediction of material flammability behavior (e.g., ignition, steady burning, and fire growth). Initially proposed in 2016^[1], this framework offers:

• Experimental measurements for a large variety of materials collected across a range of length scales (multiple test apparatus).  
• Material properties relevant to fire modeling are determined (i.e., calibrated) through automated analysis of these mg-scale and g-scale measurements.
• Calibrated properties can be used as model inputs in simulations of fire behavior conducted in the Fire Dynamics Simulator (FDS). 

The NIST Material Flammability Database has evolved to include new classes of measurement data, a growing library of automated tools for property calibration, and an ever-increasing set of target materials^[2-5]. 

Description

Objective 

To develop a database that maintains the tools (experimental and analytical), measurement data (for model calibration and validation), material property sets, and validation data needed to enable quantitative prediction of material flammability behavior (e.g., ignition, steady burning, and fire growth). 

Research Plan
The fire modeling community is working to quantitatively predict material flammability behavior (e.g., ignition, burning rate, fire growth). State-of-the-art fire models require input parameters (material properties) that describe: the decomposition reaction mechanism of combustible solids (and associated kinetics and thermodynamics) and relevant heat/mass transport properties. 

Figure 1. The NIST Material Flammability Database.  A detailed version of this project summary poster is available online: PROJECT POSTER PDF

To address this need, NIST Fire Research Division has been developing^[1] experimental and analytical tools to calibrate these material properties and validate their ability to predict flammability response across a range of configurations/scales (i.e., mg-scale thermal decomposition, g-scale gasification/burning, and flame spread over panels 0.5 m to 2.44 m tall). 

To date, these tools have been used to characterize synthetic polymers and copolymers, fiber-reinforced composite materials, porous polymer foams, and natural- and engineered-wood-products. These calibration measurements^[2,15,16], analysis tools^[3-5,11], resulting material property sets, and comparisons of experimental measurements^[6] and numerical simulations (Fire Dynamics Simulator, FDS) of full-scale fire growth behavior (model validation) are maintained on the NIST Flammability Database (Fig. 1).

Ongoing Development

The tools developed here have been applied in a range of applications including quantifying the impact of material composition on ignitability and fire growth (materials found in nuclear power plants)^[7], quantifying how differences in vegetative fuel decomposition affect CFD simulations of wildfire spread^[8], and understanding the flammability performance of products and materials used in wildland urban interface (WUI) homes and communities (noted as a high priority for fire and materials research in a recent road mapping exercise ^[14]. 

Current research applications include:

1. Calibration^[9] and validation^[10,11] data provided to support the Measurement and Computation of Fire Phenomena Working Group (MaCFP, a global effort to advance fire modeling)
2. Development of automated scripts^[13] for thermal transport property determination from gasification data 
3. Standardization of experimental data sets, material property and model parameter formatting
4. Continuous production of pyrolysis property sets (maintaining a living, growing database): apply tools to characterize additional fuels (e.g., vegetation) and fire behaviors (e.g., smoldering)
5. Quantify and validate model sensitivity (fire growth rate) to measured variations in material properties and their respective measurement uncertainties
6. Determination of material property requirements (for test material replacement)  PROJECT POSTER PDF

references

References

1. Bruns, M.C. and Leventon, I.T., Design of a Material Flammability Property Database,” ACS, 2016.
2.  Leventon, I.T. et al., “Experimental Measurement of Material Flammability at the Micro-, Bench-, and Full-Scales for Fire Model Development” ASTM Symposium on Obtaining Data for Fire Models, 2021.
3. Bruns, M.C. and Leventon, I.T., “Automated fitting of thermogravimetric analysis data,” Fire and Materials 2021.
4. Bruns, M.C. and Leventon, I.T., “Automated Characterization of Pyrolysis Kinetics and Heats of Combustion of Flammable Materials,” FAA Fire & Cabin Safety Research Conference, 2019.
5. Bruns, M.C. and Leventon, I.T., “Automated Characterization of Heat Capacities and Heats of Gasification of Combustion of Flammable Materials,” FAA Fire & Cabin Safety Research Conference, 2022.
6. Leventon, I.T., Heck, M. V., McGrattan, K.B., Bundy, M.F., and Davis, R.D., ‘The Impact of Material Composition on Ignitability and Fire Growth. Volume 1: Full-Scale Burning Behavior of Combustible Solids Commonly Found in Nuclear Power Plants’ NIST Technical Note 2282, 2024. https://doi.org/10.6028/NIST.TN.2282
7. Leventon, I.T., Heck, M. V., McGrattan, K.B., Bundy, M.F., and Davis, R.D., ‘The Impact of Material Composition on Ignitability and Fire Growth. Volume 1: Full-Scale Burning Behavior of Combustible Solids Commonly Found in Nuclear Power Plants’ NIST Technical Note 2282, 2024. https://doi.org/10.6028/NIST.TN.2282
8. Leventon, I.T., Yang, J., Bruns, M.C., ‘’Thermal Decomposition of vegetative fuels…’, Fire Safety Journal, 2023.
9.  https://github.com/MaCFP/matl-db/tree/master/PMMA/Calibration_Data/  (DOI: https://doi.org/10.18434/mds2-2586)
10. https://doi.org/10.18434/mds2-2940  
11. https://doi.org/10.18434/mds2-2812   
12. Bruns, M.C. and Leventon, I.T., “Automated Characterization of Thermal Conductivity of Flammable Materials,” ACS Fire and Polymers 2024
13. Davis, R.D., Zammarano, M., Marsh, N. “Workshop Report: Research Roadmap for Reducing the Fire Hazard of Materials in the Future,” NIST Special Publication 1220, 2018. https://doi.org/10.6028/NIST.SP.1220 
14. Ding, Y., Leventon, I.T., Stoliarov, S.I., “An analysis of the sensitivity of the rate of buoyancy-driven flame spread on a solid material to uncertainties in the pyrolysis and combustion properties. Is accurate prediction possible?” Polymer Degradation and Stability, 2023.
15. Leventon, I.T., De Lannoye, K., Measurement of the Smoldering and Flaming Heats of Combustion of Biomass and Woody Fuels, 

    US National Combustion Meeting, Boston, MA, US, 2025.
16. Greene, R., Tripi, R., Leventon, I.T., McGrattan, K., Measurement of the Average Molecular Weight of Gaseous Pyrolyzates Produced by Combustible Solids, US National Combustion Meeting, Boston, MA, US, 2025.