Did You Know Your Home’s Water Pipes Are Probably Plastic?
With all the talk about microplastics in our food, I wanted to look into the pipes in our homes.
Personal Note: I’m very sorry for the delay in publishing. We took a vacation to Florida to see the first launch of Blue Origins New Glenn rocket. Our 6 year old loves rockets and space —it was awesome! Although a bummer that all of the launches were at 1am. Quite a difficulty for a 6 year old and a wife that is 6 months pregnant. But they were troopers and really impressed me. If you can make it down to the space coast, I highly recommend it.
My research project this week was about the microplastics we keep hearing about in our water bottles. As you read this one, please remember, absence of evidence isn’t the same as evidence of harm. I do NOT want to worry anyone. But with all the talk about plastics in our water, I thought it was a good time to explore the plastic pipes that are in many of our houses. This is what I found out.
We’ve all heard the concerns about microplastics in water bottles—especially when you leave them in a hot car. But here’s a twist: the water lines running through many modern American homes are now made of plastic, too. It’s called PEX (cross-linked polyethylene). And despite its widespread use, there are no large-scale, long-term human studies—or even randomized controlled trials—confirming whether PEX is 100% safe for our health.
Before you panic, keep in mind that the absence of evidence isn’t the same as evidence of harm. It just means research on PEX as a drinking water pathway hasn’t fully caught up with its popularity. Here’s the story so far:
A Quick History of PEX
• 1960s: PEX technology emerged, originally used for radiant floor heating in Europe.
• 1980s–1990s: U.S. building codes gradually allowed its use for potable water.
• 2000s: PEX gained traction as a flexible, freeze-resistant, and cost-effective alternative to copper or PVC.
By now, it’s the go-to solution for new builds and retrofits. Architects, plumbers, and homeowners alike praise its bendable nature, fewer connection points, and resistance to corrosion.
What the Studies Say
• Chemical Leaching: Laboratory tests have detected small amounts of volatile organic compounds (VOCs), like MTBE, that can leach out of PEX into standing water (particularly when new). Researchers found these levels drop with regular use and flushing.
• Taste and Odor: Some people report a temporary plastic taste or odor from new PEX. Studies suggest it usually fades over time.
• Microplastics?: Most available data focus on chemical migration, not tiny plastic particles. Current regulatory checks haven’t flagged microplastics as a concern with PEX, but the research is still thin.
Regulatory Green Light
PEX is approved under NSF/ANSI 61, a standard that tests for any contaminants leaching into drinking water at levels above acceptable thresholds. It also meets ASTM specifications for durability and performance. Local codes rely on these certifications to ensure PEX is safe for installation.
Here’s the rub: certification is not the same as a 20-year population study. Instead, it involves lab-based testing against chemical limits. Many experts consider it sufficient. Others wonder what the unresearched long-term effects might be.
Where This Stands
• Widely Used, Light on Human Data: Millions of homes already have PEX, with very few reported issues. But we still lack large-scale, longitudinal health research tracking real-world outcomes over decades.
• Absence of Evidence ≠ Evidence of Harm: No data says PEX is dangerous. No data says it’s perfectly harmless. It’s simply a technology that outpaced in-depth human trials.
• Takeaway: If microplastics in water bottles worry you, it’s worth asking what other plastic pathways your drinking water flows through—and whether you’re comfortable with the relative unknowns.
Want to try a new perspective this week? Rethink your assumptions about what “safe” really means. Just because something passes today’s regulatory hurdles doesn’t guarantee a well of peer-reviewed, long-term RCT data. Sometimes we accept what’s proven to “work fine” without a definitive 40-year, double-blind experiment behind it.
That’s not necessarily bad—it’s just where we stand right now. If you’re feeling curious or concerned, do a little digging into how your home’s water system is built. It might surprise you how many modern houses rely on plastic from the curb to the kitchen sink.
But we also must keep in mind to always ask ourselves: “Compared to What?” Meaning, if we don’t want our water to be stored in or transported in Plastic, are we safer if it is transported in metal? Lead? (Flint?) Buckets? Rivers? All of these sources have concerns and contaminants of their own. I guess this is all to say, it’s complicated.
Stay curious. Stay positive.
-Travis
Further Reading
Here in Evanston when they were replacing some of the older pipes (we still have plenty of lead) they were removing some of the original original "pipes" by Northwestern. It wasn't even a pipe, it was basically a brick aqueduct built sometime in the 1880s. I wish I had saved those pictures they posted but it's been lost to the sands of time.