Warming and Sterilizing Towels by Microwave Irradiation

A steamed and sterilized towel was easily obtained using a home microwave oven. A small piece of gauze (7 × 7 cm) containing approximately 5 × 108 organisms in 1 mL of saline was rolled up in the moist towel which was wrapped in heat-resistant vinylidene polychloride film (wrap film). Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans in the towel were completely killed by microwave irradiation for 1 min. When three towels were irradiated simultaneously, it took 2 min for complete killing of the bacteria. In another experiment, the small gauze containing the bacterial suspension was set in a sterile plastic dish and completely dried using filtered air for a period of 3 h. After a 5-min irradiation in a microwave oven, the survival rate of S. aureus was 17%. These results indicate that a sterile steamed towel can be obtained by microwave irradiation of a moist towel wrapped in wrap film.