| Abstract: | Approximately seventy-five organic materials have been detected by gas chromatography in the thermal decomposition products of PVC and are shown by mass spectrometry and retention studies to consist mainly of aromatic and aliphatic hydrocarbons. Weight-loss experiments and time-resolved chromatography indicate that these products are formed mainly during dehydrochlorination. The products are modified by the presence of oxygen but no oxygenated organic species have been detected. Experiments to specifically monitor the production of phosgene from the decomposition of both a rigid PVC sheet and a PVC polymer in air are recorded. Phosgene has not been detected and direct seeding techniques have been used to investigate the detection limits of this material. PVC is known to release the toxic gases, carbon monoxide and hydrogen chloride, when involved in fires. It is shown that the minor products, including phosgene, make little or no contribution to the overall toxicity of the decomposition products. |
