How to Microwave a Kitchen Sponge to Kill GermsWritten on: August 8th, 2012
Reducing incidence of foodborne illness by just 10% would mean 5 million fewer Americans would get sick each year! After seeing this recent Centers for Disease Control and Prevention estimate, we started thinking about kitchen safety tips to help keep our families safe from these all-too-common illnesses.
Worst Places for Germs in the Kitchen
Washing hands before cooking and eating are a good, commonsense way to start. Earlier this year, a Chicago Tribune article added that kitchen sponges are a major source of microbes, saying that when NSF International (an independent public health organization) swabbed various items in homes, the kitchen sponge was by far the germiest, harboring 150 times more bacteria, mold and yeast than a toothbrush holder!
The University of Arizona’s ‘Dr. Germ’ – aka microbiologist Prof. Charles P. Gerba – agrees. He writes that sponges are the worst place for germs in the kitchen, providing a damp, nurturing environment for fecal bacteria from raw meat to fester. Yuck! In a New York Times interview, Gerba said that the cleanest-looking kitchens are often the dirtiest because “clean” people wipe up so frequently, they spread bacteria all over the kitchen. Amusingly, some of the cleanest kitchens, Gerba claims, are in the homes of bachelors who rarely wipe up counter tops.
Another recent study found that preparing one simple meal can contaminate up to 90 per cent of kitchen surfaces touched, which may spread foodborne illness. Volunteers were asked to prepare a chicken stir-fry, fresh green salad, and packed kids’ lunch. Results showed significant cross-contamination in the kitchen, which spread to other hand-contact surfaces, kitchen towels, cloths and sponges.
Microwave Sponges to Kill Germs
Moms Against Cooties would like to be able to use and reuse sponges without fearing that we were spreading germs. So, we set out to find the best way to clean sponges that have been in contact with foods such as raw egg, uncooked meat or raw vegetables. Turns out that the microwave oven may offer the simplest effective option, according to University of Florida researchers.
The scientists reported that simply microwaving sponges (completely wet, never dry) for two minutes at high power killed or inactivated over 99 percent of pathogens in sponges that had been soaked in a “witch’s brew” of fecal bacteria, viruses, protozoan parasites and bacterial spores.
Zap Sponges… But Watch Out
The researchers recommend “zapping” kitchen sponges every other day or so. Watch out though – the zapped sponges will be really hot and steamy, so should be left in the microwave for a few minutes to cool. And obviously, this method won’t work if the sponges contain any metal. Another option is to put the sponge into a dishwasher for a full wash and dry cycle.
How do you keep your family safe from foodborne illness? We’d love to hear your tips.
5 High power may vary among microwave ovens, but this point is not addressed by the researchers. The researchers used a Sharp, Model R-630D microwave oven with a rotating glass plate, a frequency of 2,459 MHz, and power of 1,100 watts.