Data center owners and engineers spend enormous amounts of energy protecting their facilities against the obvious threats — power loss, cooling failures, cyberattacks and more. But one of the most insidious risks to uptime is nearly invisible, grows silently for years, and often traces back to components no one considered threats: walkways, cable and runway trays, electrical metallic tubing (EMT), and other supporting infrastructure components.
That risk is zinc whiskers.
What Are Zinc Whiskers?
Zinc whiskers are microscopic, hair-thin crystalline filaments that spontaneously grow out of zinc-coated metal surfaces over time. They aren’t caused by contamination, poor installation, or a manufacturing defect in the traditional sense — they’re a byproduct of internal stress built into certain zinc coatings during the plating process. As that stress slowly relaxes, it pushes zinc atoms outward, forming whiskers that can grow to several millimeters in length over months or years.
Individually, a zinc whisker is nearly weightless and invisible to the naked eye. But data centers move enormous volumes of air through raised floors, plenums, and cable pathways to keep servers cool — and that airflow is exactly what dislodges whiskers and carries them into sensitive electronics. Once inside a server, switch, or power distribution unit, a conductive whisker can bridge two closely spaced circuit traces, causing intermittent short circuits, arcing, and hard-to-diagnose equipment failures. Because the failures are often transient and don’t leave obvious physical evidence, zinc whisker contamination can go undiagnosed for a long time while quietly degrading reliability.
Zinc whiskers are definitely not a new problem. In fact, the issue dates back more than 20 years, such as when the Colorado Secretary of State’s office had to build an entirely new data center after zinc whiskers were discovered to be the cause of computer failures and recurring outages. The problem has simply accelerated in recent years due to the aging of data centers built with certain zinc-coated components, including steel EMT.
Why Galvanized Steel EMT Is a Concern
The zinc whisker risk isn’t necessarily about all galvanized steel — the risk goes up or down depending on how the zinc coating was applied. Coatings that are electroplated (electrogalvanized) tend to retain much higher internal stress than coatings applied by hot-dip galvanizing (in which the tube is completely submerged in molten zinc), and that added stress is the underlying driver of whisker formation. A thick, alloyed hot-dip coating is far less prone to whisker growth than a thin, highly stressed electroplated layer.
This matters a great deal for data center construction because steel EMT — the thinner-walled conduit often used throughout power and low-voltage runs — is predominantly manufactured using an electrogalvanizing process. Steel strip is typically formed into tube, electric-resistance welded, and then run through a continuous electroplating line to apply the zinc coating. That process results in a thin zinc layer that is well suited to EMT’s tight dimensional tolerances, but it also produces exactly the kind of stressed coating associated with whisker growth.
Some steel EMT manufacturers have recently developed new galvanization processes, but these typically fall short of traditional hot dip galvanizing. True hot dipping results in a thick zinc coating that can interfere with the tight inside dimension (ID) tolerances required for EMT. So, the new processes attempt to achieve a thicker layer than electro-galvanizing, but a thinner layer than hot dipping. Unfortunately, only time will tell if these new tactics can successfully contain the zinc over time, and ultimately reduce or eliminate zinc whisker risk.
The bottom line is this: any galvanized steel product, including EMT, contains a relatively thin layer of zinc, and therefore runs the risk of becoming a long-term liability when installed anywhere near sensitive IT equipment. And because zinc whiskers can take years to develop, the risk isn’t apparent at commissioning. It shows up later, as a facility ages, in the form of mysterious intermittent failures that are expensive and time-consuming to trace back to their source.
The Cost of Discovery: What Happens Once Zinc Whiskers Are Found
If zinc whiskers are confirmed in a live data center, the response is rarely quick or inexpensive. Because standard vacuuming and cleaning can actually aerosolize whiskers and spread contamination further through the facility, remediation requires specialized protocols, including:
• Containment of affected areas
• HEPA-filtered vacuuming capable of capturing particles down to fractions of a micron
• Specialized, controlled wipe downs
• Continuous air scrubbing to clear suspended particles from the space
Plus, because whiskers regrow as long as the zinc source remains in place, cleaning alone is only a temporary stopgap. Lasting resolution requires identifying and physically replacing the offending galvanized steel — whether it’s EMT, raised-floor tile, cable tray or another component — with a non-zinc-whisker-forming alternative.
While some remediation providers apply a clear-coat encapsulant directly over the affected galvanized surface after HEPA-vacuum cleaning — an attempt to lock existing whiskers in place and create a physical barrier to stop them from reaching the airflow — this is another short-term or interim measure. There’s really only one way to guarantee the problem goes away for good: removing the source permanently.
Needless to say, removing and replacing components in an active data center is expensive enough. But the even larger cost can be the operational requirements of remediation — including thorough assessments, powering down and removing affected components, coordinating downtime windows, migrating workloads, and scheduling around service-level commitments. This would be a serious undertaking in any facility, let alone a data center running live mission-critical loads.
Eliminating the Risk at Initial Construction: BLUE LIGHTNING Aluminum EMT
The most effective way to manage zinc whisker risk is by removing galvanized steel components from the equation entirely. That’s exactly what happens when Penn Aluminum’s BLUE LIGHTNING Aluminum EMT is used in data center construction — for both electrical and data wiring.
Because BLUE LIGHTNING EMT is manufactured from naturally non-corrosive aluminum, rather than steel (which requires corrosion protection), there is no zinc coating that can break down over time, no internal plating stress to relax, and no whisker growth mechanism at all. For mission-critical environments where long-term reliability is non-negotiable, that’s a fundamental, built-in design advantage.
While stopping zinc whisker risk is enough of a reason to choose BLUE LIGHTNING aluminum EMT, it’s only the beginning of a long list of advantages compared to steel EMT:
• Lighter weight (1/3 the weight of steel EMT)
• Easier and faster to install
• Reduced fatigue and injury risk
• Lower cost than steel EMT
• Increased sustainability
• Naturally corrosion-resistant
• Non-sparking
• Internally-coated for easier wire pulling
Check out our BLUE LIGHTNING page to read more about its many advantages, and learn more about the sustainability of aluminum conduit and EMT here, including important third-party documentation such as Environmental Product Declarations (EPDs) and Declare Labels.
The Smart Choice for Mission-Critical Construction
Zinc whiskers are a slow-building, hard-to-detect threat that can cause serious damage and equipment failures. For data centers, where uptime is everything, that’s a risk worth designing out from day one.
For architects, engineers, building owners and contractors involved in specifying electrical and data cable raceways for mission-critical facilities, the choice is increasingly clear. Rather than accepting the long-term liability of zinc whisker growth from electrogalvanized steel EMT, that risk can be removed completely with BLUE LIGHTNING Aluminum EMT — while also providing a lighter weight, safer, more cost-effective, and more sustainable solution.
