Interaction between low-extractable polyvinyl chloride (PVC) pipe and high-purity water containing 50 ppb of dissolved ozone is investigated for a period of five weeks. Rinse water analysis from the pipe effluent showed an increased level of chloride ion following ozonation. A number of analytical investigations such as scanning electron microscopy, x-ray photoelectron spectroscopy, and static secondary ion mass spectroscopy revealed chemical interactions between the PVC pipe surface and the dissolved ozone. Organic solvent cement used for joining the pipe is also affected chemically by the action of ozone. Oxidative degradation of the PVC by dissolved ozone can be explained by dehydrochlorination mechanism.