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Literature pertinent to the ignition by smoldering cigarettes of upholstered furniture and mattresses (soft furnishings) was searched through early 1986. This included literature on the smoldering behavior of cigarettes in air; their behavior on a variety of substrates simulating soft furnishings; mechanism of smoldering in substrates; relative cigarette ignition resistance of substrates; and relative propensity of commercial cigarette packings to ignite substrates. According to the reviewed literature, the smoldering behavior of cigarettes on substrates differs from that of cigarettes burning in air: on substrates, cigarette temperatures tend to be lower, and burning rates slower. These differences seem to be larger for substrates which ignite than for those which self-extinguish after the cigarette burns out. The characteristics of soft furnishings which insure resistance to cigarette ignition have been established, but those of cigarettes with low propensity to ignite furnishings have not. No mathematical model has been reported for the interaction of cigarette and substrate, but some empirical data do exist.

In an attempt to model real-life burn accidents, garment assemblies were burned on adult-size mannequins and the temperature distribution over the mannequin surface determined. Anaesthetized, shaved rats were exposed in openings of the mannequinns in the spatial arrangements encountered in real-life garment fires. The correlation between the depth of burn into the skin and the temperature observed on the mannequin surface near the exposed skin seemed fair. In other experiments, the interaction of burning fabrics and depth of burn was studied by means of simulated garments fitted to anaesthetized, shaved rats. Garment geometry was found to affect the burn injury potential as much as fabric parameters. It is discussed in terms of initial fabric to skin, fabric to mannequin, and outerwear-underwear distance (these distances often change during the fire due to heat shrinkage of thermoplastic fibers, turbulence, etc); formation of chimney spaces between fabric layers and the mannequin surface; and firestops such as belts. Other experiments covered the effect of combinations of various fabrics, such as dress-slip assemblies. Garments made from flame-retardant (FR)-treated cotton fabric and 100% thermoplastic fibers did not ignite in our experiments when used as single layers. When combined with polyester/cotton blends in outerwear-underwear assemblies, these fabrics caused smaller areas of the mannequins to be raised to elevated temperatures than the blend fabrics alone. This effect was particularly marked for the FR treated cotton. In our experiments, polyester/cotton blends seemed to have more potential for causing injury than comparable, 100% cotton fabrics. 100% thermoplastic fiber fabrics appeared to have a low injury potential. The effect of fabric weight on the area of the mannequin raised to elevated temperatures was not clear cut, though it was obvious that heavier fabric caused more severe injury to exposed skin, and were more difficult to extinguish by beating out the flames, than light fabrics.

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