Evaluation of the Hazard of Fire Resistant Materials Using Measurements from Laboratory and Parallel Panel Tests

This paper describes new concepts for evaluating the fire propagation hazard of exposed polymer materials exhibiting low heat release rates (typically less than 200 kW/m2). While the intent of most fire propagation models is to predict details such as the position of flame or pyrolysis fronts as a function of time in a room-corner scenario, engineers often simply need to know whether a material will support sustained fire propagation or not. To accomplish this objective, a 2.4-m high parallel panel configuration is studied as a reference scenario for determining fire propagation behavior apart from other complicating factors, such as flashover potential or excess pyrolyzate production. Coupled to this test configuration is laboratory analysis of the polymer that provides quantitative information on two key parameters for a simplified predictive model of fire behavior: 1) the ratio of the heat of combustion to the heat of gasification and 2) particulate yield of the polymer flames. Procedures for obtaining these parameters are described for three materials, two nominally identical polyvinychloride polymers of different thickness and a fire-retarded polypropylene. The behavior of these three materials in the parallel panel configuration when exposed to gas burner flames of varying intensity is analyzed and compared to model predictions. Based on the analysis, it is concluded that accurate determination of the heat of gasification in an inert, nitrogen environment is important for understanding the hazard of fire resistant materials