Revisiting the “Steiner Tunnel” test method covered under ASTM E84: An overview and analysis of the test method

The “Steiner Tunnel” test, which is standardized under ASTM E84 and UL 723, is used to comparatively assess surface-burning characteristics, namely, flame spread and smoke release from a wide range of building materials and assemblies. While the method is well known to fire safety engineers, it is not as well understood by material scientists who develop new fire safe materials that will meet this test. Understanding how the test measures flammability and smoke is critical to designing materials that can meet requirements that reference E84 and UL 723. This article primarily discusses the ASTM E84 test, discusses the history of the method, how it measures flame spread and smoke release, and how mounting samples in the test method affects flame spread and smoke release. Finally, there is discussion on test methods that could be used for qualitative screening tools for materials developed for the E84 test.