The Ductile Iron Pipe Research Association (DIPRA), the trade group for PVC pipe’s chief competitor in the municipal water market, has found a new venue for its PVC attack ads.

This time it isn’t USA Today but the American Society of Civil Engineers’ Civil Engineering Source, where the group placed a “Sponsor Content” piece, misleading engineers into thinking that the U.S. EPA’s vinyl chloride review “raises questions for pipe specifications.”

DIPRA’s playbook should look familiar. It includes a stock photo, a claim that vinyl chloride is a carcinogen (without clarifying that hazardous detectable levels of it aren’t found in PVC), and links to DIPRA’s “Informed Water Choices” campaign, which houses all sorts of inaccuracies about PVC. Same scare messages, same scare formula.

Notably absent from the piece is any reference to the benefits of iron pipe—the material DIPRA exists to promote. That approach makes the post look like it’s simply meant to educate readers, when it’s really making a competitive argument. It also raises an obvious question: Why can’t the iron pipe industry promote its own products without attacking competing materials?

Disclosure isn’t neutrality

To ASCE’s credit, the piece is labeled as an advertisement. But average unsuspecting readers, those who may not distinguish paid content from conventional engineering news, could easily mistake it for a public service announcement. DIPRA invokes terms such as “stewardship,” “due diligence,” and “follow the science” to stoke unwarranted concerns among engineers regarding PVC pipe safety.

PVC pipe is safe

The takeaway for every reader is simple: today’s PVC pipe is certified to independent, stringent safety standards to ensure it poses no risk to public health.

The specific standard is known as NSF/ANSI 61, which “establishes minimum health-effects requirements for the chemical contaminants and impurities that are indirectly imparted to drinking water from products, components and materials used in drinking water systems.”

The standard dictates that PVC pipe must keep residual vinyl chloride monomer below 3.2 milligrams per kilogram, an infinitesimally small amount. PVC pipe must also pass a leaching test against the U.S. EPA’s drinking water standard.

What the science actually shows

Looking at the research on vinyl chloride in modern PVC water pipe helps clarify the safety question.

In one study of finished PVC products, including water pipe:

“...[C]urrent residual vinyl chloride monomer (RVCM) levels in all grades of PVC resin typically are significantly below acceptable levels and ... resulting fabricated products are typically at nondetect levels to very low parts-per-billion (ppb) levels.”

Put simply, trace levels of vinyl chloride in modern pipe are almost universally undetectable.

For an added layer of assurance, the U.S. EPA has enforced a Maximum Contaminant Level (MCL) for vinyl chloride in drinking water, 2 parts per billion, for decades. The Association of Metropolitan Water Agencies, whose utilities serve more than 160 million people, told the agency that any risk from PVC pipe is “adequately managed” by that standard and by NSF/ANSI 61.

What EPA has actually said about PVC pipe

While utterly misleading overall, DIPRA’s ad concedes key facts about the EPA’s evaluation of vinyl chloride: the process is ongoing, no risk determination has been issued, and the review “doesn’t target PVC pipe directly.” That’s a long way of saying, “there’s no news to report, but we’re going to deceive the public about it anyway.”

A 1970s problem, solved in the 1970s

As it’s wont to do, DIPRA conflates PVC pipe safety with claims that exposure to vinyl chloride, a chemical used to make PVC, causes cancer. But DIPRA doesn’t want you to know this: the workplace exposure problem identified in the 1970s was addressed with stringent worker protections and does not reflect the safety of finished PVC products today. According to the Vinyl Institute, vinyl chloride “is chemically transformed in the polymerization process and its presence in almost all cases is non-detectable in finished PVC products.”

DIPRA even cites a rare liver cancer isolated to workplace exposure to vinyl chloride in industrial settings, a problem that was addressed and corrected more than 50 years ago.

In 1974, the Occupational Safety and Health Administration (OSHA) cut the workplace vinyl chloride exposure limit from 500 parts per million (ppm) to 1 ppm—that’s like shortening a 500-mile drive, roughly Los Angeles to Las Vegas and back, to a single mile.

Industry then adopted innovative manufacturing practices, which, according to a 1997 CDC retrospective, “almost completely eliminated worker exposures.” The result: new cases of the cancer tied to the chemical in the 1970s were virtually eradicated.

Furthering DIPRA’s fear mongering, the group cites a laundry list of other cancers it desperately wants the public to think are linked to common vinyl chloride exposure—without clarifying that those links were once tied to high occupational exposures (which was rectified 50 years ago), or that any exposure to vinyl chloride at harmful levels is an exceedingly rare and isolated occurrence.

And it most certainly doesn’t take place when drinking a glass of water from the tap.

The bottom line

As always, our message is simple. Decisions about water infrastructure and public health should rest on the evidence. If DIPRA wants to make the case for ductile iron, rather than falsely attack PVC, ASCE’s readers are well equipped to judge the facts on the merits.

But DIPRA didn’t do that here. The group published a competitively motivated narrative replete with distortions about PVC pipe for the purpose of deceiving civil engineers.

And that’s just sad and pathetic.