A used sponge contains bacteria that multiply rapidly under favorable conditions. Usually, nutrients and moisture in the sponge are sufficient to support growth of these micro-organisms. Successive use of the same dirty sponge can transfer bacteria from one surface to another during the 'cleaning' process. To minimize the potential spread of bacteria, sponges should be decontaminated regularly. In this study, several physical and chemical decontamination methods were evaluated. Heating a contaminated sponge for one minute in a microwave over or boiling a sponge in water for five minutes resulted in a more than 99.9 percent reduction in the number of bacteria. Soaking contaminated sponges for five minutes in a solution of bleach or a cleaner that contains a quaternary ammonium compound also resulted in a more than 99.9 percent reduction of bacteria. Other products such as hydrogen peroxide, isopropyl alcohol, ammonia, and vinegar were effective in reducing the bacterial load in laboratory-inoculated sponges but not in consumer-used sponges, which contained a higher concentration of bacteria.