Fire Safety Science Digital Archive

Tests have been made in which the toxic gases and smoke produced from fires in rooms of polyurethane flexible foam in amounts representative of those likely to be found in domestic premises, have been measured. The tests have shown that all types of polyurethane foam tested, (unmodified, flame retardant, high resilience cold cure, and a recently introduced improved foam) ignited from small additional amounts of cellulosic material, and, except for the smallest fire load of two cushion squabs, were completely burned. The last three foams went out leaving some residual foam when only two cushions were tested. Although the smoke and toxic gases produced during the fires of two squabs were small and unlikely to present a risk to occupants, fires of larger amounts, representative of fully furnished rooms, produced sufficient smoke to impede escape, and amounts of the toxic gases, carbon monoxide, hydrogen cyanide and nitrogen oxides, that would present a lethal risk even after dilution of the fire gases with cool air to temperatures that could be borne for short periods. Tolylene diisocyanate (TDI) was not detected in any test. The detection limit was 3 ppm. The rate of production of smoke and toxic gases was such that, if they escaped from the room on fire to the remainder of a dwelling, the atmosphere in the whole of the dwelling would become hazardous in a few minutes.