The Hidden Hazard of Zinc Whiskers

As always, it began with a mystery.  Repeated explosions sent maintenance teams scurrying out of the data centre at a modern brewery in Toronto.  The large suitcase-sized Cisco router kept electrically exploding, and no one could determine the reason.

Let’s face it: a disruption of the flow of data, let alone the flow of beer in Canada, was unacceptable.  Cheers to that.

Unknown to everyone summoned to examine the temperamental machinery, a microscopic culprit was relentlessly attaching itself to surfaces in the room, creating strands barely the width of a human hair that were 100% conductive and 100% problematic.

In detective mode, I utilized power quality metering and various other tests to zero-in on the cause, deploying six Zinc Whisker kits under the floor tiles, in the ceiling, on racks and on the equipment itself.

And there they were, thousands of strands of Zinc Whiskers captured in photographs using a powerful electron scanning microscope. 

Zinc Whiskers were a big problem in the 1970s and 80s, and they’re resurfacing thanks to the use of cheaper zinc coatings, inferior steal, and half-price deals coming from off-shore suppliers.

The coatings are used on the bottom of tiles covering raised floors that allow access to data lines. Zinc is also used on the metal T-bars linking drop-down ceiling tiles.  At the beer plant, the Zinc Whiskers were being sucked into the Cisco router by its powerful fan. Being superconductors, the electrical charges would build and build until the explosions occurred.

Our tests found the troublesome strands floating throughout the room and landing on every surface.  We installed a room air cleaner with specialized filters to capture that level of particulate as fine as 100 microns, and we used a customized vacuum.  The “dirty” tiles emitting the whiskers were identified and removed and ultimately the floating whiskers were purged and eliminated at the source.

The brewery wasn’t the last of it. We’ve been called in to track down similar problems in hospitals, offices, and other manufacturing facilities.  In one case, we found zinc whiskers on the actual data rack, designed to hold the computer equipment; a result of low-quality metal coming from China.

The Zinc Whisker invasion isn’t about to slow down, as more and more of this cheap metal and cheap zinc coating infest our vital data centres or adjacent spaces (On one occasion, I sourced the whiskers from a different floor in an office tower…floating on currents through the HVAC system INTO a data room).

They say everyone likes a mystery.  But when it comes to Zinc Whiskers, it’s definitely a cautionary tale.