Carbon beds containing organics, in contact with air, exhibit potential for thermal runaway. To accurately define the spontaneous oxidative thermokinetics, appropriate calorimetric techniques are required. A stopped-flow heat-flux calorimetry for oxidative heat-rate measurement is presented in conjunction with the results generated by accelerating rate calorimetry. The stopped-flow method eliminates many experimental uncertainties encountered with the conventional continuous gas-sparging method, and generates accurate and reproducible heat-rate data in a single test run. This technique is particularly useful in solid oxidation systems containing volatile organics.