This article presents an up-to-date review of chemical compositions, particularly those bearing the elements of halogen and phosphorus, and structural features of flame retardants which have been chemically incorporated in polyurethane foams. Particular Anthony J. Papa is project scientist with the Chemicals and Plastics Division, Union Carbide Corp., South Charleston, W. Va. He received his Pk.D. degree from Washington State University in 1960, and did postdoctoral work at Purdue University in 1961 and exploratory research on polyurethanes as leather substitutes at Du Pont from 1962 to 1966. He has had experience in the areas of urethane, isocyanurate, and phenolic foams, and since 1966 has worked in the fields of rigid and flexible foams.directed toward the construction marketplace, but at the present time the biggest outlet for flame-retardant rigid polyurethanes is still as insulation for the transportation industry.
Test MethodsA review of all flammability test methods applicable to polyurethane foams is beyond the intent of this article. The most commonly employed small and medium scale tests for rigid foams include the ASTM D 1692 test, the Butler chimney test, the Bureau of Mines flame penetration test, the ASTM E 162 radiant panel test, and the ASTM D 568 vertical bar test. The ASTM E 84