3- Are zinc bar tops really antimicrobial?

Another challenge facing the zinc countertop industry revolves around the claim that zinc and copper are antimicrobial.  So, are most zinc bar tops really antimicrobial?  To investigate this claim, we have to look at the whole countertop system, and not simply the choice of metal.

Now zinc itself is, in fact, antimicrobial, though scientists still struggle to describe exactly how its ionic properties eliminate the bad guys across different surfaces. However, zinc alloys have some copper present, which can also help with the fight. We’ll talk about alloys later, but copper also contains tremendous antimicrobial properties.

After extensive antimicrobial testing by the Environmental Protection Agency, it was found that 355 copper alloys, including many brasses and bronzes, were found to kill more than 99.9% of bacteria within two hours of contact. Normal tarnishing or patina was found not to impair antimicrobial effectiveness. So this is a good thing!

However, most bar tops are not solid zinc or copper, and herein lies the rub. Most bartops use plywood, a biologically susceptible substrate, as the core onto which metal is attached.

So once fluid finds its way past the barrier of zinc, brass, or copper, it has the potential to set up shop just below the surface where it can’t be addressed. Because bacteria love this damp environment, they can take hold on scuppers, drink rails, and service areas of the bar when not properly attended to. 

So the construction details that most in the industry use lend themselves to bacterial infiltration and outbreak. I have personally seen this issue with dozens of projects, and it is a difficult condition to overcome, even with better training of bar staff.

So another challenge facing the zinc countertop industry is that current construction assemblies are, in fact, not taking full advantage of the antimicrobial properties of zinc because of construction techniques.