| Abstract: | ![]()
Measurements of the extent of vinyl chloride migration from specimens of processed poly(vinyl chloride) (PVC) are used to calculate the diffusivity of vinyl chloride in PVC pipe compound. The migration is strongly affected by temperature and is slightly larger into water than into air. The equation for calculating vinyl chloride migration from PVC must be generalized to recognize a variable diffusivity to be useful for non-isothermal situations, as in the case of the measurements. The diffusivities calculated from the data with the generalized equation were confirmed by migration measurements from one in. pipe. Predictions with the calculated diffusivities and the generalized equation show that PVC pipe with a 3 mg/kg concentration of residual vinyl chloride will not release quantitatively detectable amounts of vinyl chloride (< .002 mg/kg) in a realistic time frame in potable water distribution. |
