As States Replace Lead Pipes, Plastic Alternatives Could Bring New Risks

Additional chemicals that have been found leaching from PVC pipes include benzene, styrene, tetrahydrofuran, methylene chloride, and other volatile organic compounds. These compounds, which may be released into drinking water when PVC pipes are exposed to high heat, are variously linked to cancer, immune suppression, or damage to the nervous and reproductive systems.

Meanwhile, Beyond Plastics says existing systems to protect the public from PVC-related contaminants are inadequate — and potentially compromised by industry influence. The EPA doesn’t have legally enforceable drinking water standards for the vast majority of chemicals used commercially by humans, including organotins, and those that it does regulate are usually tested for at water treatment plants, before water travels through the pipes that lead to people’s homes.

To ensure pipes are safe, the EPA relies on NSF, an international nonprofit formerly known as the National Sanitation Foundation. NSF sets its own standards for how much of certain chemicals are allowed to leach from PVC pipes, and charges pipe manufacturers for a certification saying their products meet those standards.

Enck raised concerns about conflicts of interest in the standard-setting process, not only because NSF gets industry funding from those piping certification fees but because industry representatives sit on the NSF committees that propose and vote for water quality and exposure standards. (Public health experts also sit on these committees, but one former member told Beyond Plastics that their voices were “absent or very quiet.”)

“Shouldn’t this be the role of government?” Enck said. “We would not expect a coal plant to certify whether they’re complying with air pollution laws.” She also noted that NSF typically only tests for leaching chemicals on a short-term timeframe, potentially failing to capture what happens as PVC sits in the ground over years and decades.

NSF did not respond to Grist’s request for comment. The EPA said it has supported the development of NSF’s plumbing safety standards and that they require evaluations to ensure chemicals that leach into drinking water are “below levels that may cause potential adverse human health effects.”

Beyond Plastics says more toxicological data is urgently needed to characterize the full chemical consequences of using PVC pipes. But in the meantime, the organization urges policymakers to consider piping made of simpler, less chemical-laden materials, like copper or stainless steel. These pipes cost more than PVC — but they would only increase the total cost of replacing lead pipes by about 5 percent, according to Beyond Plastics.

Plus, there are nonmonetary costs of plastic to consider, including its carbon footprint and the toxic air pollution caused by its production. In February, the Norfolk Southern train derailment in Ohio highlighted yet more risks as it spewed vinyl chloride and other plastics-related chemicals into the air and soil of East Palestine.    

“There are very serious impacts,” Enck said. “Plastic is not cheap when you take everything into account.”

Joseph Winters is a reporter for Grist. This story was originally published by Grist. You can subscribe to its weekly newsletter here.