Assessment of Potential Microbial Contamination in the Laundry and Decontamination Dry Cleaning System (LADDS)

摘要

Survival studies using microorganisms representative of hospital and nonhospital environments were conducted under conditions simulating the Laundry and Decontamination Dry Cleaning System (LADDS). The LADDS is based on the continuous reuse of Freon-113 (1,1,2-trichlorotrifluoroethane) as a cleaning solvent. The laboratory tests were performed under various conditions of temperature(room temperature and 45 C), detergents (anionic and cationic surfactants), moisture (0.1% and minimal water) and with soiled clothing swatches. Populations of the vegetative microorganisms Escherichia coli and Staphylococcus aureus, representative of nonhospital LADDS applications, were significantly reduced under all conditions where detergents were employed at 45 C. An acceptable level of disinfection (greater than six log reduction) was obtained within a 30 second to 10 minute time frame in these experimental systems, depending on the microorganism, detergent and water content. Significant reductions were also observed in systems where soiled and inoculated clothing was present, however, six log reductions were not attained. Spores of Bacillus globigii, representative of hospital LADDS applications were virtually unaffected in all experimental systems studied. The incorporation of the NBC neutralization option may provide improved sporicidal activity. Further work is required to evaluate the rate of spore removal from contaminated clothing and the feasibility of incorporating a disinfecting agent (compatible with Freon-113) in the LADDS.