Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Assessment of a Medium-Scale Polyurethane Foam Flammability Test.



Thomas J. Ohlemiller, John R. Shields


Six polyurethane foams of widely varying flame retardant levels have been tested in two modes: as four, fabric-wrapped cushions in a chair mock-up based on California Technical Bulletin 133 and in a two foam slab Vee configuration that uses multiple propane flames to simulate fabric burning. The latter test was developed as a way to: (1) use less foam to assess real world foam flammability behavior and (2) avoid the use of fabrics in this assessment since they do not have reproducible properties. For the six foams tested as chair mock-ups with a polypropylene fabric, the Vee test correlates well for peak heat release rate but not for time to that peale In a more limited assessment of chair mock-ups having polyester fiber wrap between the fabric and foam, it was found that this material overwhelms even high levels of flame retardants and gives a serious fire regardless of the nature of the foam. One foam, which contained expandable graphite, gave very good initial fire behavior by suppressing foam melt flow entirely. However, it ultimately began to disintegrate and yielded a serious fire as a result of the dropping of burning, solid foam chunks. New non-melting foams based on carbon nano- fibers, now under development, will have to have to exhibit greater "char" coherence if they are to avoid this performance pitfall.
Technical Note (NIST TN) - 1495
Report Number


polyurethane foams, flammability tests, flame retardants, fabrics, cushions, test methods, chairs, flexible foams, heat release rate, experiments, fire behavior


Ohlemiller, T. and Shields, J. (2008), Assessment of a Medium-Scale Polyurethane Foam Flammability Test., Technical Note (NIST TN), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed February 21, 2024)
Created February 1, 2008, Updated November 10, 2018