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Are your granite counters teeming with bacteria?

Granitebacteria_4I had never heard the words granite and bacteria in the same sentence until the solid-surface manufacturers started using it to sell their products. They claim granite counters are not safe and harbor bacteria, while their composite counters (Corian, Silestone and the like) are safe. Really? Haven’t we been using granite counters for decades, even centuries? Where’s the outbreak of food-borne illness? And what about tile and grout? Why aren’t we all dead?

Over at Garden Web’s remodeling forum, homeowners are discussing the merits of Stonemark, a granite product carried by Home Depot that is soaked in some kind of super-duper sealer to make it more impervious.

With granite fabricators and sellers saying granite is safe, and with solid-surface manufacturers and sellers saying it isn’t, whom do you believe?

For an impartial view, I asked Susan Serra, a certified kitchen designer who writes a robust blog called the Kitchen Designer. Here’s what Susan had to say:

Is harboring bacteria a concern? Oh, tricky question here! How could I say no? Of course it’s a concern. And the kitchen is a wonderful place to harbor all sorts of exotic bacterial living organisms. You’re never really alone in the kitchen. . . !

I think there are several ways to look at this issue. The first is universal. Clean your hands and your countertops properly before and after working with food. Cleanliness goes nearly all the way in preventing food-borne illnesses, originating in the kitchen.

Probably, the most perfect of countertop surfaces to keep bacteria to a minimum would be stainless steel or solid surfaces. These countertops would have to have a curved (cove) turn at the rear of the countertop, to avoid a seam where bacteria could congregate and grow. The countertops would also have to have integral sinks of the same material, again, to avoid a seam. Then, you’re as protected as you can be.

I don’t know about you, but I’m not interested in going back to the ’70s with a short, coved backsplash, and I don’t necessarily want an integral sink of the same material.

My advice is NOT to be afraid of granite. Tests have shown that a mix of 10% vinegar, with water, will kill 99.9% of bacteria. Use it in a spray bottle.

Me, I see bacteria and granite as a nonissue, providing one uses appropriate cleaning methods. I might add, as an anecdotal note, that I have had three tile countertops in my life (supposedly the worst for bacteria) totaling approximately 22 years. My family is never sick, certainly never with gastro-intestinal illnesses. Hot, soapy water works for us!

Will you get these (more sanitary) countertops so that you can clean off your last bit of bacteria and settle for a different aesthetic than you would have chosen otherwise?

Just be aware that when you go to answer the phone, a pesky ant or fly may track raw chicken juice across the "better" countertop surface and then crawl or fly away before you return. A kitchen is not a confined laboratory. There will be some bacteria in the best of circumstances.

How about you? Do you have granite counters? Have bacteria taken over your home? Are we taking this bacteria thing too far so the corporations can sell us more chemicals?


6 Comments on Are your granite counters teeming with bacteria?

  1. J. Krynen - ARS Construction, Whittier // December 14, 2007 at 7:56 am //

    While I agree with Ms. Serra’s analysis that granite countertops are probably as safe as most surfaces if regularly cleaned, I must advise against the use of vinegar any stone surface. Vinegar, also known as acetic acid, will slowly eat into and remove the glossy shine of the counter surface. Marble and limestones are more susceptible, but granite will also dull from the corrosive effect of the acid. There are many anti-bacterial cleaners on the market that are more pH balanced, or use Ms. Serra’s follow-up advice; hot soapy water works great, gets into all the tiny pits and is alkaline (non-acidic).

  2. Kudos to J Krynen on pointing out the damage caused by improper cleaning agents. The damage done by the cleaning agents is the crux of the problem, how to clean granite without damaging the stone.
    In addition, the vast majority of the bacteria will never come in contact with the cleaning agent, being deep in the pores, crevices and cracks. Sure a few will be killed on the surface, but the population will rebound in a few days if of the more dangerous type like Salmonella, Campobacteria, or E coli. This is exactly why they are dangerous, their speed of reproduction. One becomes a billion in just a few days. In addition, kill rate is never 100% and those left become or are resistant to the agent used for cleaning.
    The CDC reports that food posioning cases are surging but have not attributed it to any one cause as of this date. In view of this, it would be better to have a material that can be cleaned with most effective cleaners without worry of damage to the countertop.
    Based upon these reasons, I would have to respectfully disagree with Susan Serra on granite and bacteria being a non issue.

  3. One thing you can do to reduce bacteria on your kitchen countertops is never, never bring your purse into the kichen and set it down on your counter. A study done shows 25% of purses have E Coli on them–so leave your purse in the entryway or the car.
    http://www.snopes.com/medical/disease/purse.asp

  4. Don’t forget that granite gives off Radon!

  5. Kitchen design,
    it does indeed have Radon emissions from the Uranium decay chain. Here are some studies that prove it.
    http://solidsurfacealliance.org/granite-Radon-issues-page-2.html

  6. Radon is found everywhere in the Earth. However, solid surface manufacturers and associations would have you believe that there are dangerous levels in a granite countertop. That couldn’t be furher from the truth. Here are the bottom line facts, and don’t let these companies misinform you: http://www.stonemark.com/granite-radon.htm

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