Behavioral incapacitation of rats during full-scale combustion of natural-fiber and synthetic polymeric furnishings

Thirty Long-Evans rats served in each of six experiments to determine the time-course of behavioral incapacitation during exposure to full-scale combustion of household furnishings. Three experiments involved furniture constructed of natural-fiber materials, and three experiments involved furniture dominated by synthetic polymers. Groups of rats, previously trained to stable levels of performance on three tasks (rotorod, operant shock-avoidance, and a jump/escape test), were exposed to combustion products at three locations in a full-scale burn facility. Animals were removed from the exposure environment when they reached each of three operationally defined stages of behavioral incapacitation. Measures of time-to-incapacitation revealed that a given degree of behavioral dysfunction occurred 3 to 5 times sooner during exposure to the combustion of polymeric as compared to natural-fiber furnishings. Temperature, hydrocarbons, carbon dioxide, and oxides of nitrogen were the most frequent statistically significant correlates of time to behavioral incapacitation in polymeric fires; carbon monoxide, carbon dioxide, and total hydrocarbon concentration were the most frequent statistically significant correlates of behavioral dysfunction in natural-fiber fires. Animals that survived the first 24-hour interval after exposure showed no evidence of lasting behavioral incapacitation.