The diffusion of chloroform and carbon tetrachloride from rigid PVC pipe and rigid CPVC pipe into water

Abstract

The objective of this study was to determine whether or not chloroform (CHC13) and carbon tetrachloride (CCl,) diffuse from poly(viny1 chloride) (PVC) or chlorinated poly(viny1 chloride) (CPVC) pipe into water in the absenceof solvent cement. Milli Q water (water which has been deionized, demineralized, and purified of residual organic matter) and tap water were permitted to stand in specimens of recently extruded pipe for 14 days in an attempt to simulate a condition of prolonged stagnation. The CHC13 and CCll in the water were then measured utilizing an analytical method sensitive to 0.01 pgll (ppb).CHCl3 and CCl4 do not diffuse from Geon PVC or TempRite CPVC pipe or fitting compounds in significant quantities under these t a t conditions. Where sporadic positive responses were noted, these were in the low or fractional pg/l (ppb) ranges and are far lower than levels commonly found in chlorinated tap water. The low, sporadic values obtained for CHC13 and CCl, in both Milli Q and tap water do not permit the calculation of meaningful diffusion constants.