Foodborne illnesses aren’t likely to be discussed openly when consumers are purchasing a kitchen countertop. However, the marketing campaigns of various countertop suppliers hint at this subject when they talk about how sanitary and how easy to clean their products are.
Solid surface manufacturers, in particular, emphasize that their products are non-porous, in contrast to granite and other natural stones which, it is said, can harbor dangerous bacteria in small surface crevices. The stone marketers respond, with some indignation, that bacteria are found everywhere, including on both granite and solid surface materials, and that any consumers who are concerned should wash their countertops with antibacterial soap.
Perhaps a blend of truth and hype can be found on both sides. I decided to investigate this topic in order to learn just how significant this issue is.
One thing that’s clear is that the risk of foodborne illnesses is very real. The Centers for Disease Control estimate that 76 million people get sick from food-related illnesses every year in the U.S. Although the majority of these illnesses are relatively minor, more than 300,000 Americans are hospitalized and 5,000 die as a result each year.
It is also clear that many of these illnesses originate in places other than residential kitchens. Whether the problem developed on the farm, in a food processing plant or in a restaurant or other commercial kitchen, many such illnesses have absolutely nothing to do with the kitchen countertops in our homes. Despite this, the fact remains that most of our meals are still prepared at home, and much of that work takes place on our countertops.
Therefore, it is also clear that our kitchen countertops do play a role, whether in promoting or in slowing the spread of these illnesses.
Countertops and Cleanliness
I turned to the National Sanitation Foundation (NSF) for additional information. It developed NSF/ANSI Standard 51, which regulates a wide variety of materials used in food equipment. To summarize, their analysis of kitchen countertop materials is favorable to stainless steel and most major brands of solid surface and engineered stone, which are all certified by NSF for use in a “food zone” or an area designed to come into direct contact with foods.
Chalk up a point for the marketing campaigns for solid surface materials. Neither plastic laminates nor natural stones (such as granite) are considered acceptable materials in this type of application. NSF observes that natural stones are “too porous” to qualify. To be fair, health departments and building inspectors rely on this standard only when evaluating restaurant and institutional kitchens, rather than home kitchens.
Additionally and quite logically, the NSF strongly supports design standards that “prevent the harborage of vermin and the accumulation of dirt and debris.” In particular, the standard calls for a radius on inside corners of at least 1/8”, which suggests coved backsplashes; and also calls for permanently sealed joints and seams, which favors integral sinks and smooth, non-porous seams. These objectives certainly seem to be easier to achieve with solid surface materials than with either natural stone or engineered stone products. On the other hand, natural stone slabs properly installed in a home kitchen come far closer to that ideal than ceramic tile countertops, plagued by hundreds of feet of porous grout lines.
NSF publishes a flyer for home cooks called “Three Steps to a Safer Kitchen.” Second on the list, after proper hand washing, is keeping the kitchen clean, specifically, dishes and utensils, cutting boards, sponges and countertops. Its recommendation is to wash countertops with hot, soapy water before and after food preparation. The final step is to take special measures to prevent cross-contamination of produce or cooked foods by the juices of raw meat, poultry and seafood, through the use of separate or freshly washed cutting boards and knives.
While all of this may seem like basic common sense, research studies funded by the Food and Drug Administration show that many home cooks fail to comply with these standards. A 1997 survey of 106 households showed that 76% failed to take steps to prevent cross-contamination, 29% failed to refrigerate leftovers properly and 57% neglected hand washing. Other surveys confirm that, despite their own shortcomings in behavior, most consumers are far more likely to blame a restaurant or a food processing company for a bout of food-related illness than they are to accept their own personal responsibility.
In the past 10 years, supermarket shelves have been flooded with new products that claim potent antimicrobial or disinfectant powers. But are such products really necessary in order to clean up a countertop after the all-too-frequent spills of raw chicken juice? And, does it really make that much difference what sort of countertop is installed?
Inexpensive solutions of either bleach or ammonia are effective in getting rid of bacteria, although bleach and ammonia should never be mixed, because that potent blend will release poisonous chlorine gas.
A non-toxic and inexpensive solution is suggested by a study conducted by the Hospitality Institute of Technology and Management. Its researchers contaminated six countertop surfaces with a broth colonized by E. coli bacteria. The study found that simply washing the surfaces with dish detergent and water, followed by rinsing with clean water, resulted in a significant reduction of the bacteria count. Even more dramatic results were achieved with a final sanitizing rinse of 10% white vinegar in water. This simple treatment reduced bacteria levels on stainless steel by 230,000,000 to 1 and granite by 80,000,000 to 1. The overall performance of granite was excellent in this study, which did not evaluate solid surface materials.
In other words, just a little bit of vinegar helped get rid of over 99.99999% of the bacteria. It is most effective to apply it with a spray bottle, instead of a dirty dishcloth or sponge. Granite industry experts caution, though, that vinegar should be used only on those types of granites that are resistant to mild acids, and should never be used on marble, limestone or travertine.
Still, when it comes to countertop sanitation, I believe that nothing can beat a solid surface countertop with a coved backsplash and an integral sink, although I would grant a “tie” to a similar installation in stainless steel. But by far the most important factor is the cleanliness of the individual cook, rather than the countertop material. Nothing I learned should rule out a natural stone countertop, as long as the cook sanitizes all food contact surfaces properly.