EFFICIENCY DETERMINATION OF COMMONLY USED DISINFECTANTS OVER SEVEN DAYS OF STORAGE
Arpita Roy, S. M. Rezowan Kabir* and Fouzia Ferdows Khan Chowdhury
ABSTRACT
Among commonly used broad spectrum disinfectants ethanol, isopropyl alcohol (IPA) and savlon are well known. Although their effectiveness against different group of microorganisms has already been established but till now effectiveness of old preparation of any of these is not established. This study was aimed to find out whether the efficiencies of prepared disinfectants solution remain same or reduced during storage. Effectiveness was tested by applying 70% ethanol, 70% IPA and 3.3% savlon solutions individually on surface of stainless steel sheets previously contaminated with Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Staphylococcus aureus and Candida albicans as well as one non-sterile sheet. Following the application of disinfectant after 30 seconds, 5, 10 and 15 minutes number of surviving organisms were counted. Same test was done on first, fourth and seventh day of solution preparation and their effectiveness were compared. In this study it was found that Ethanol and IPA effectively killed 99.99% populations of test organisms and most of the non-specific contaminants from non-sterile surfaces on both 1st and 4th day’s test, but failed to kill 99.99% of test organisms at 7th day’s test. Savlon was found effective against all the test organisms and non-specific contaminants on 1st, 4th and 7th day. So, the obtained results suggested that efficiency of prepared solutions remained constant up to 4th day of preparation for 70% ethanol and 70% IPA and at least up to 7th day for 3.3% savlon.
Keywords: Disinfectant, effectiveness, storage, decontamination.
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