Dezincification of Brass PEX Fittings

Dezincification is a little-known but costly failure that plagued certain brass PEX fittings installed between the mid-1990s and the early 2010s. If your home was built or re-piped during this period, there’s a chance you have fittings at risk of premature failure. But even over the past few years, it has continued to occur in some brass fittings. 

What is Dezincification?
Dezincification is a type of corrosion where zinc is selectively leached out of yellow brass, leaving behind a weakened copper-rich metal. Over time, this process can weaken the fitting until it cracks or crumbles. Restrict water flow as corrosion products clog the passage. Cause leaks, often hidden until water damage has occurred. In the field, it shows up as chalky white crust, blue-green staining, or (if cut open) a redish tan , porous interior.
Why It Happens
The main triggers include aggressive water chemistry—chlorine/chloramine additives, low or high pH, high oxygen content, and stagnant water. Older yellow-brass alloys (high zinc content) were especially vulnerable. That’s why manufacturers shifted to dezincification-resistant (DZR) alloys or polymer (PPSU) fittings after repeated failures and lawsuits.
Known Brands and Markings Affected
The problem is tied to specific fittings and date ranges. Look for stamped markings on the body of the fittings: 

Zurn (QestPEX / “QPEX”), ASTM F1807 fittings (c. 1996–2010)
Markings: “QPEX,” “Q PEX,” or “Z PEX” (sometimes with F1807). These fittings were part of the ZurnPEX Products Liability Litigation. 

Kitec (IPEX), used with orange/blue PEX-AL-PEX (late 1990s–2007)
Markings: “Kitec” or “KTC,” often stamped with ASTM F1974 or CSA B137.9/10. Large class-action settlements addressed failures in these systems. 

NIBCO / CPI Dura-PEX, ASTM F1807 fittings (2000s–2012)
Markings: “NIBCO F 1807”. Covered under lawsuits that addressed premature failures and leaks.

Signs to Watch For
A white or green crust forms at PEX connection points. Leaks or dampness near fittings. Hot vs. cold water flow imbalance due to internal blockage. Powdery, pinkish metal if a fitting is removed.

Final Thoughts
Dezincification was a widespread problem that affected certain brands and alloys during a narrow window of time. If your home belongs to that era, don’t ignore the signs. A few failing fittings today can be a warning shot before a major plumbing failure tomorrow.  Below are a few examples from past inspections!

Trace Inspections can often locate hard-to-find issues like this by using infrared cameras, moisture meters, and even specially designed endoscopes to look inside wall cavities.