1.1 These fire-test-response test methods describe small-scale laboratory procedures for determining the comparative burning characteristics of solid plastic materials that, due to specimen thinness and nonrigidity, may distort or shrink when tested using Test Method D 3801. A flame is applied to the base of specimens held in a vertical position and the extinguishing times are determined upon removal of the test flame. 1.2 The classification system described in Appendix X1 is intended for quality assurance and the preselection of component materials for products. 1.3 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. Note 1 -These test methods and ISO 9773 are technically equivalent. Note 2 -For rate of burning of nonrigid solid plastics in a horizontal position, formerly Test Method B of these test methods, see Test Method D 635, section 9.4. 1.4 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. For specific hazard statements, see Warning in 6.1.