Release of Bisphenol A and Other Volatile Chemicals from New Epoxy Drinking Water Pipe Liners: The Role of Manufacturing Conditions

Cured-in-place-pipe (CIPP) technology has begun to be adopted for drinking water pipe repairs, and limited information exists about its drinking water quality impacts. CIPP involves the manufacture of a new plastic pipe inside a buried damaged pipe. In this study, the chemical composition of the raw materials and CIPP water quality impacts were examined. Numerous (47) VOCs and SVOCs were found in the resin and two hardeners were studied. TGA results indicated that new CIPPs contained about 3.2-4.8 wt% VOC. A controlled static headspace analysis using PTR-TOF-MS detected eight protonated ions (/ < 114) with mixing ratios above 1 ppb and phenol was identified as the most abundant VOC released into air. The analytical methods were unable to identify 99.9% of the extractable VOC mass. A 5% shorter curing duration had no impact on the chemical residual left in the CIPPs, but a 5% hardener reduction prompted an increase in the amount of monomer remaining. Both normal drying and quick drying formulations released similar amounts of 2-EHGE and BPA into drinking water. Laboratory results scaled to 4-36 in. diameter pipes indicated only 4 in. diameter CIPPs would cause BPA levels to exceed a U.S. state drinking water standard, EU, and WHO drinking water limits. Flushing and drinking water VOC and SVOC testing should be conducted before use. Additional studies of resins, manufacturing conditions, and wastes generated, are recommended. At present, the limited information available about these materials has shifted the burden of potential health and financial costs to the users.