This test method covers a fire-test-response procedure. This test method describes a procedure for measuring the minimum concentration of oxygen that will just support flaming combustion in a flowing mixture of oxygen and nitrogen. Methods are provided for testing materials that are structurally self-supporting in the form of vertical bars or sheet up to 10.5 mm thick. These methods are suitable for solid, laminated or cellular materials characterized by an apparent density greater than 15 kg/m3. The methods may also be applicable to some cellular materials having an apparent density of less than 15kg/m3. A method is provided for testing flexible sheet or film materials while supported vertically. Note 1--Although this test method has been found applicable for testing other materials, the precision of the test method has not been determined for these materials, or for specimen geometry's and test conditions outside those recommended herein. This test method may be used to measure and describe the properties of materials, products, or assemblies in response to heat and flame under controlled laboratory conditions and shall not be used to describe or appraise the fire hazard or fire risk of materials, products, or assemblies under actual fire conditions. However, results of this test may be used as elements of a fire risk assessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular end use. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Specific hazards statements are given in Note 2. Note 2: Warning: During the course of combustion, gases or vapors, or both, are evolved which may be hazardous to personnel. Note 3--This test method and ISO 4589-2 are technically equivalent when using the Type A gas measurement and control device accuracy as described in 6.4.