This standard specifies a test method for determining the combustion performance of rigid foam plastics using the vertical burning method, applicable for assessing their vertical combustion performance under laboratory conditions. The standard requires that the specimen be vertically fixed inside a chimney with a glass front, ignited by a Bunsen burner, and then the flame height, burning time, and residual mass percentage during combustion be precisely recorded to evaluate performance. It should be noted that this method is not applicable to materials that melt, drip, or fuse during combustion, and its evaluation results cannot be used as a basis for assessing the fire hazard of materials under actual usage conditions.