A Quick Way to Sterilize Your Sponges
Here's a household hint from a team of researchers at the University of Florida: Your sponges and scrubbing pads might benefit from some time in the microwave oven.
The scientists tested the effects of microwave radiation on different types of bacteria that commonly contaminate sponges and scrubbing pads by soaking cellulose sponges in wastewater filled with pathogens, then zapping them for increasing periods. The study, published in the most recent issue of the Journal of Environmental Health, found that nearly 100 percent of bacteria were inactivated after two minutes in the microwave on high power. "We actually mimicked an extreme situation by soaking the sponges in raw sewage," says Gabriel Bitton, the microbiologist who led the team. "A real kitchen sponge or pad will probably have far fewer microbes and bacteria. And to take care of E. coli, which has caused so many problems, 30 seconds is enough. One minute is probably enough for the rest of the bacteria."
Make sure your sponges are thoroughly soaked before they go into the microwave. Recent reports of people causing fires by microwaving dry sponges have prompted the researchers to post a list of safety precautions on their website. Bitton cautions against putting metallic scrubbing pads in the microwave and notes that, while soapy sponges may be microwaved, those containing certain chemical composites or detergents may release toxic fumes. "The study has great practical value," says Rolf Halden, an assistant professor of environmental health at Johns Hopkins University and cofounder of the Hopkins Center for Water and Health. Halden does worry about toxic fumes but foresees a day when sponge makers will label their products "microwave safe."