mijostyn - The bit about heated PVC making HCL is the funniest part.The kinetics and mechanism of dehydrohalogenation of PVC is well documented in the scientific literature. I had the opportunity to study the surface chemistry of UV induced dehydrohalogenation of PVC many years ago using photoelectron spectroscopy. The dehydrohalogenation process can be induced thermally or via UV exposure and does produce HCl. That is one reason stabilizers are used in PVC.
Many years ago people observed their Monster Speaker Cable turning green through the clear PVC jacket. This was due to dehydrohalogenation of the PVC jacket producing HCl which reacted with the copper conductor forming copper chloride.