Microwaves Can Ignite, as Well as Sterilize, Sponges

Friday, January 26, 2007

Kitchen sponge users, beware. Microwaving sponges can sterilize them but can also apparently have a downside: Some sponges may burst into flames.

The Washington Post reported Wednesday that new research showed microwaving a kitchen sponge for two minutes can kill most germs. Since then, several unhappy readers have called to report that when they tried this at home something startling happened: Their sponges ignited.

In response, The Post contacted Gabriel Bitton of the University of Florida, who did the research, for advice.

"I have been microwaving sponges for the past two days and nothing bad happened in my home nor in my lab," Bitton responded yesterday in an e-mail.

Bitton noted, however, that he had tested only cellulose sponges, using a microwave with a maximum of 1,100 watts of power, never exceeding 90 percent of its power.

"We have no data from synthetic sponges or loofah sponges," Bitton said. "If the customer has a microwave with a higher power, he/she should experiment a little bit by increasing the exposure time gradually."

Bitton added this advice:

· Sponges should be fully soaked with water.

· Metallic scrubbing pads should never be put in a microwave.

· Soapy sponges can be microwaved, but not those containing detergents and other chemicals.

Finally, Bitton cautioned: "Beware of hot sponges after exposure."

-- Rob Stein

© 2007 The Washington Post Company