A study was conducted to determine the flammability characteristics and thermal degradation of urethane cellular plastics used in aircraft interiors. Model urethane polymers were prepared, and the effect of the chemical structure of isocyanates and ployols on performance during fire exposure were studied. A series of non-fire-retarded rigid-urethane foams was synthesized and evaluated to serve as the basis for further research directed toward the synthesis of fire-retarded systems. A series of fire- retarded rigid foams was synthesized incorp- orating reactive and non-reactive fire retardants in various concen-trations. The flammability characteristics of these cellular plastics were evaluated using test methods for the ease of ignition, flame propagation, fire endurance, smoke emission, and oxygen index as criteria. Based on the information obtained, a series of optimized rigid foams, which incorporated reactive and auxiliary fire retardants, was prepared and evaluated. Similar studies were carried out using formulations representing flexible urethane. (Author, modified-PL).