PVC Cable Fire Toxicity using the Cone Calorimeter

Electrical cables with PVC sheaths were investigated for their ignition characteristics, heat release and toxic yields using the cone calorimeter. 40 KW/m² was required to get a significant heat release for PVC. A heated Temet Gasmet FTIR was used for the toxic gas analysis. Gas samples were taken from the cone calorimeter diluted exhaust duct and transferred to the FTIR using a 190°C heated sample line, heated pump and filter and a second 190°C heated sample line between the pump and the FTIR. The FTIR measurement zone was also heated at 190°C so that no loss of HCl and other condensable gases occurred. This heated sample system enabled the theoretical HCl yield, based on the chlorine content of PVC, to be measured. This indicated that there were no other significant chlorine products in the well ventilated fires. A peak yield of 0.45 for HCl was found. There were significant yields of the irritant gas acrolein and formaldehyde and acrolein was the most important toxic gas. The PVC sample and the char that remained after the test were analysed using TGA and the results showed that only 41.6% of the chlorine in the sample was lost as HCl in the cone calorimeter test, the rest remained in the char.