Yellow Brass Plumbing Claims in Washington

William T. Cornell and Sommer B. Clement

Although the copper alloy known as “yellow brass” has caused problems in residential plumbing systems in some southwestern states and Hawaii, claims for yellow brass-related property damage and leakage in Washington can be defended, and at least one arbitration panel has dismissed such claims.

A common material used in the manufacture of plumbing fittings, yellow brass typically consists of varying proportions of copper, zinc, lead, and iron.  The term “yellow brass” was coined to describe brass alloys with greater than 15 percent zinc content, in contrast to “red brass” alloys with less than 15 percent zinc content.

Figure 1: A yellow brass plumbing fitting removed from a PEX domestic water system.

Some engineering consultants in Washington espouse the theory that yellow brass used in plumbing systems is capable of a type of corrosion known as “dezincification.”  Dezincification occurs when the zinc separates from the alloy, altering the fitting and rendering it capable of premature failure and leakage.  Because the plumbing systems are concealed within the wall cavities, these experts advocate completely re-piping the plumbing system, which requires extensive drywall repairs and re-painting.

Zinc’s proclivity for corrosion is well known.  Zinc has long been used as a sacrificial anode on metal ship hulls because it corrodes before steel and other metals critical to the ship’s operation.  During the 1950s, potable water systems in Gothenburg, Sweden, which has particularly corrosive water, experienced a type of dezincification corrosion known as “meringue,” where the pipe became plugged by zinc residue.  Although the meringue-type corrosion affected the functionality of the piping, it did not result in leakage.

During the mid-1990s, meringue dezincification caused obstructions in hot water recirculating systems in Las Vegas.  Las Vegas is known for corrosive water, among other things.  More recently, meringue corrosion and other problems, including failure of fittings by stress corrosion cracking, spawned a series of class action lawsuits against yellow brass component manufacturers including Zurn, RTI/Uponor, and IPEX/Kitec.  These class action claims arose as a result of corrosive water chemistry, together with other factors capable of accelerating corrosion, which are not present in Washington plumbing systems.

Yellow brass-related claims in Washington have evolved and vary by specific fitting.  In PEX domestic water plumbing systems with yellow brass compression fittings, for example, some engineering consultants theorize that corrosion of the barbs on the fitting, some of which are used to maintain the compression attachment, could change the profile of the barbs, causing the PEX pipe to loosen from the fitting.  Although these consultants initially argued this condition could result in spontaneous leaks within the wall cavity and required an immediate re-pipe, the theory has evolved to one of reduction of the life of the plumbing system, requiring premature, but not immediate replacement of the plumbing system.  In fact, there is no evidence of dezincification corrosion ever causing an actual fitting failure or leak in Washington.

Figure 2: A 500X magnification of a barb on a fitting that evidences minor dezincification (copper colored portion).

Unfounded expert opinions are subject to challenge to the extent they are inconsistent with generally accepted theories within the scientific community.  In addition, techniques, experiments, or studies using a theory must be capable of producing reliable results.  In an arbitration award issued in October 2012 concerning the Fifth and Madison condominium located in Seattle, a three-arbitrator panel rejected the yellow brass dezincification theory and found no liability for yellow brass claims in potable water and hydronic piping systems.  The award included a determination that the leakage theory propounded by plaintiff’s expert was “unlikely to occur as a result of dezincification and, if there is some dezincification, it will not result in the failure of the fitting.”  Although the plaintiff’s expert had attempted to draw parallels between short-term failures in Hawaii and the potential for failures in the Fifth and Madison condominium, the panel determined that the water chemistry in Hawaii was significantly different, and that there was no admissible evidence of any dezincification-related failures in the Seattle area that could support the plaintiff’s expert’s theory.  Thus, the arbitrators were persuaded by the defense expert’s testimony that the yellow brass fittings were not defective, could last more than 35 years, and there was no need for replacement in the short term.

Successful defense of yellow-brass plumbing claims requires close interaction between defense counsel and expert consultants, including a metallurgical analysis of the fittings in question.  Installed fittings typically exhibit stamp designations that indicate they were manufactured and tested in accordance with ASTM specifications and approved for use.  Defense experts believe there is nothing inherently wrong with using yellow brass in plumbing fittings.¹  In fact, ASTM specifications permit use of copper alloys with as much as 37 percent zinc content (well above the 15 percent threshold for yellow brass) in PEX plumbing systems.  Defense experts examine the conditions present in the system in question, measure and determine the source of any present corrosion, and identify the composition of the fittings.  In addition, defense experts challenge the conclusions drawn by opposing counsel including the applicable standards, test methodologies used, and useful life projections.

Please contact our office if you should have any questions concerning yellow brass claims.

¹In March 2011, a test standard known as ISO 6509 became effective in the U.S.  This standard imposes a highly controversial accelerated test for purposes of categorizing a fitting for manufacturing.  Any fitting that passes the test is deemed “dezincification resistant.”  A prudent practice for installation of brass fittings manufactured after March 2011 in Washington is to use only “dezincification resistant” fittings, stamped “DZR.”