FED-STD-372

Abstract

This method of test describes a procedure for measuring the critical radiant flux of horizontally mounted carpet floor covering systems exposed to a flaming ignition source in a graded radiant heat energy environment, in a test chamber. The specimen can be mounted over underlayment, a simulated concrete structural floor, bonded to simulated structural floor or otherwise mounted in a typical and representative way. <br>This method measures the critical radiant flux at flame-out. It provides a basis for estimating one aspect of fire exposure behavior for floor covering systems. The imposed radiant flux simulates the thermal radiation levels likely to impinge on the floors of a building whose upper surfaces are heated by flames and/or hot gases from a fully-developed fire in an adjacent room or compartment. The method was developed to simulate an important fire exposure component of fires which may develop in corridors or exitways of buildings and is not intended for routine use in estimating flame spread behavior of floor covering in building areas other than corridors or exitways. Caution should be used in applying this test in instances where fuel loading is anticipated to be over 5 lbs. per square feet and/or there are other combustibles in the corridor. <br>Critical radiant flux, while an important fire characteristic of carpet floor covering systems, is just one of a number of fire system variables which must be considered in predicting corridor floor covering fire behavior. Thus, while this measurement permits rank ordering of carpet floor covering systems on the basis of this important fire property, it should not be considered that compliance with a particular level of critical radiant flux will insure against all corridor fires.