Bacteriological quality of fabrics washed at lower-than-standard temperatures in a hospital laundry facility

Abstract

The authors determined whether the bacteriological quality of fabrics cleaned in a hospital laundry could be maintained at wash temperatures lower than 75°C by the use of economically reasonable formulas and wash conditions. Three groups of bacteria were examined to determine bacteriological quality: aerobic, nonexacting chemoorganotrophs, staphylococci, and total coliforms. The distribution of bacteria on soiled fabric was patchy, with staphylococci and total coliforms ranging from <0.1 to >4 x 103 CFU/cm2 and chemoorganotrophs ranging from <0.1 to >5 x 105 CFU/cm2. The washing process routinely produced fabric containing <1 CFU/cm2. Low temperature (47.8 to 60.0°C) wash procedures eliminated all bacterial groups at least as effectively as did high-temperature procedures. The effectiveness of bacterial density reduction at low temperatures was augmented by increased concentrations of bleach. Successful low-temperature washing such as that shown here may save both energy and money for hospitals.