NFPA 270

Abstract

This is a fire-test-response standard. This test method provides a means of measuring smoke obscuration resulting from subjecting essentially flat materials, products, or assemblies (including surface finishes) not exceeding 25 mm in thickness to specified levels of thermal irradiance from a conical heater, in a single closed chamber, in the absence or presence of a pilot flame, and when placed in a horizontal orientation. The principal fire-test-response characteristic obtained from this test method shall be the specific optical density of smoke from the specimens tested, which is obtained as a function of time, for a period of 10 minutes. Other fire-test-response characteristics are also permitted to be determined. An optional fire-test-response characteristic measurable with this test method shall be the mass optical density, which is the specific optical density of smoke divided by the mass lost by the specimens during the test. The fire-test-response characteristics obtained from this test are specific to the specimen tested, in the form and thickness tested, and are not inherent properties of the material, product, or assembly tested. This test method does not provide information on the fire performance of the test specimens under fire conditions other than those conditions specified in this test method. This standard measures and describes the response of materials, products, or assemblies to heat and flame under controlled conditions but does not by itself incorporate all factors required for fire hazard or fire risk assessment of the materials, products, or assemblies under actual fire conditions.  Fire testing of products and materials is inherently hazardous, and safeguards for personnel and property shall be employed in conducting these tests. This standard does not purport to address all of the safety problems, if any, associated with its use. It shall be the responsibility of the user of this standard to establish the necessary safety and health practices and determine the applicability of regulatory limitations prior to use.  Purpose. (Reserved)