safety assessments. The fire-test-response characteristics obtained from this standard are not intended to be used as the sole basis for such assessments.1.1 This standard details a method for assessing the critical radiant flux of horizontally mounted floor-covering systems when subjected to a flaming ignition source within a controlled radiant heat environment in a test chamber. The specimens are installed over underlayment, a simulated concrete structural floor, adhered to a simulated structural floor, or mounted in a manner that is representative of typical installations.

1.2 The standard quantifies the critical radiant flux at the point of flame extinction. It serves as a foundation for evaluating one characteristic of the fire exposure response of floor-covering systems. The radiant flux applied mimics the thermal radiation that would affect a building’s floors from flames or hot gases, or a combination of both, originating from a fire in an adjacent space. This standard is designed to replicate a key fire exposure scenario for fires that occur in building corridors or exitways and is not intended for regular use in assessing the flame spread behavior of floor coverings in other areas of a building, aside from corridors or exitways. Refer to Appendix X1 for guidance on the correct application and interpretation of results from this test.

1.3 The SI units provided in this standard are considered the standard units of measure. No alternative units of measurement are included within this standard.

1.4 The body of this standard includes references to notes and footnotes that offer additional explanatory details. These notes and footnotes, excluding those found in tables and figures, are not to be considered as mandatory requirements of the standard.

1.5 This standard is employed to measure and describe how materials, products, or assemblies react to heat and flame under controlled conditions. However, it does not, on its own, provide all the necessary factors for fire-hazard or fire-risk assessments. The fire-test-response data derived from this standard should not be the sole basis for such safety evaluations.