The toxic products formed during thermal oxidative degradation of neoprene and polyvinyl chloride compositions, urethane foams, and various untreated and treated woods were determined quantitatively on a gram-per-gram basis. Quiescent and dynamic decomposition conditions were employed. Analyses were performed using high-vacuum separations, gas chromatography, mass spectrometry, infrared spectroscopy, and wet chemical methods. The main toxic species found included CO, hcl, hcn, so2, anhydride, aniline, and furfural. Thermogravimetric analyses were performed on all the compositions, and the data were correlated to available formulating information and product formation.