The use of a respirometer is introduced as a novel technique for measuring the oxidation rates of thermally degrading polymers. A dual channel respirometer with fuel cell detectors demonstrates sufficient sensitivity to measure the oxidation rates of low-density polymeric samples at ambient temperatures in a relatively short period of time. Samples of low-density polyurethane foam were aged for various lengths of time in sealed chambers at temperatures ranging from 23 to 110 degrees C. The extent of oxygen depletion was measured by flushing the chamber with air and comparing the oxygen concentration in the chamber flow to that of a reference flow. Oxidation rates of the 0.1 g/cm(3) polyurethane foam could be measured in less than 600 h of aging time at 23 degrees C. This corresponds to approximately 2 ppm oxidation by weight. Oxidation rates of the foam were used to calculate acceleration factors over a wide temperature range, including ambient conditions. Acceleration factors for the compressive force of the polyurethane foam were determined at elevated temperatures. Assuming that the aging behavior of compressive force of the foam is correlated to its oxidation rate, it is possible to calculate acceleration factors for the compressive force and predict the performance of the foam Elsevier Ltd. All rights reserved.