Piping Up About Plumbing Standards

Piping Up: NSF experts clear up the misconceptions about PEX residential standards.

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When it comes to remodeling, I often find myself turning to HGTV and PBS and shows like “This Old House” and “Fixer Upper” to get my creative juices flowing. If you’re building a new house or undertaking a major home-improvement project, or if your landlord is updating your bathroom, you probably know exactly what I’m talking about. Paint colors, a polished-chrome or rubbed-bronze faucet, lighting fixtures — I jump right in to make those choices.

PEX piping is becoming a popular plumber pick because of its successful 30-year track record in Europe. Usually sold for water supply piping and in-floor radiant heat lines, it’s now one of the most frequently used materials for residential plumbing in Canada and the United States.

But when the conversation with my contractor turned to cross-linked polyethylene (PEX) piping, I admit I was stumped. Plus I’d read some buzz on social media about pollutants to drinking water in home piping. I wanted to make sure the piping he was installing was safe, so I reached out to the water experts at NSF to get the facts about PEX piping, its safety for drinking water pipes and all I needed to know before signing the remodeling contract.

Meets Safety Standards
PEX tubing is tested and certified to various product standards, including NSF/ANSI/CAN 61: Drinking Water System Components - Health Effects. This means it has gone through rigorous testing to ensure that it doesn’t introduce contaminants into drinking water at unsafe levels.
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Study Limitations
In reviewing a study that suggested PEX piping causes odors in drinking water in addition to contaminants, NSF researchers found several limitations in how the study was conducted, including:
- Nonstandard methods of testing pipe were utilized.
- Test samples were exposed to conditions that do not reflect any real-life situations.
- The quantities of chemicals were not reported.
- There was no study of the potential adverse health effects of the chemicals.
- Researchers did not report the controls used to inform the loss of chlorine.
- The U.S. EPA taste and odor testing method was not used in the intended manner.
- The source water control was not analyzed for samples taken in a building.
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Testing, Testing
The NSF mark includes the assurance that there are strict product-testing procedures in place to guarantee that the data collected is accurate and appropriate for the conditions, such as:
- The testing models real-life scenarios for reasonable drinking water usage.
- Test results are quantified and compared with known health-based drinking water criteria.
- Annual testing of the plumbing is conducted to verify continued product safety.