When it comes to kitchen sinks, stainless steel is still the cleanest, says a University of Georgia researcher.

To find the best sink type, Joe Frank, a food microbiologist with the UGA College of Agricultural and Environmental Sciences, put today's kitchen sink surfaces through food safety tests in his lab.

New and Old Materials Tested

"So many new materials are being manufactured for kitchen sinks," Frank said. "We wanted to see how they stand up to food pathogens that can be found in your home kitchen."

For the test, Frank compared sinks made of stainless steel, mineral resin and polycarbonate plastic. All were tested in both new and used conditions.

Frank exposed the sink surfaces to Staphylococcus aureus, a pathogen commonly found in household kitchens. "We selected S. aureus because it's harder to kill," he said.

The surfaces were exposed to the pathogen and then cleaned with chlorine, ammonia, bleach and liquid sanitizers.

Abraded Surfaces Harder to Clean

All abraded or used sinks were harder to sanitize. But Frank found the hardest surface to clean was the mineral resin sink. The easiest to clean, he found, was the new stainless steel sink.

"New products, especially plastics, are really easy to clean. But once a surface is abraded, it's just harder to clean," Frank said. "A new stainless steel surface is rougher initially, but it doesn't abrade easily, either."

Frank said all surfaces will become harder to sanitize the more they're used. Using proper cleaning supplies is the key to keeping your kitchen sink free of harmful bacteria and reducing your family's risk of food-borne illnesses.

Clean and Sanitize

"Remember that a cleanser only removes bacteria," Frank said. "You have to use a sanitizer to kill bacteria."

UGA food safety specialists recommend combination cleaning in the kitchen.

"Always wash and clean your kitchen surfaces first with a detergent solution," said Elizabeth Andress, an Extension Service food safety specialist with the UGA College of Family and Consumer Sciences. "Then clean the surfaces with a chlorine bleach-solution spray."

Andress said you can easily prepare a chlorine-solution spray at home by mixing 1 tablespoon of bleach with a gallon of water. "Then put the solution in a spray bottle and use it to spot clean your kitchen surfaces," she said.

She recommends using this solution within a few days. The diluted bleach solution will lose its strength when exposed to the air. "It's best to mix up a fresh solution each time you plan to sanitize," Andress said.

(Staphylococcus aureus image courtesy of the Centers for Disease Control and Prevention. Sink image courtesy Advanced Tabco Inc.)