Effectiveness of Surface Disinfectants
...ate for their household. The EPA’s main requirement for a disinfectant is that is rids a surface of 95% of available microorganisms. Among many factors that influence effectiveness are degree of contamination (amount of fluid needed for cleansing and temperature needed for more effectiveness), percentage of efficiency in riding surfaces of microorganisms, concentration, quantity needed for maximum decontamination of a surface and how environment friendly is the agent. Various studies have been performed to determine which household disinfectants are the best. Dr. Rufula Williams, a doctor of medicine, determined through experimentation on various disinfectants that the best agents to use were commercially made household disinfectants instead of natural, environment friendly products. Through his experiment, he was able to conclude that Lysol and Clorox Bleach were more effective in killing disease causing agents than any other household disinfectant. In this experiment, we hope to evaluate the effectiveness of five widely used household disinfectants. We hypothesize that after an area has been contaminated and cleansed with a disinfectant, that the number of remaining colonies will be less than 99.9% of that of the control. Materials and Methods The experiment began by choosing five popular disinfectants that were used for exterminating surfaces from disease-causing microorganisms. The disinfectants chosen in this experiment were Simple Green, Lysol, Bleach, and 95% Ethanol. One milliliter of each solution was diluted in a 25 ml graduated cylinders. The dilution used was one milliliter of disinfectant to 10 milliliters of hot water. Concentrated solutions were transferred to the graduated cylinders by using sterile pipettes. Mixtures were shaken so that the two substances could mix thoroughly throughout the solution. After all solutions were made, the area for experimentation was chosen and prepared. The area chosen was a Biology lab bench at Mercer University. The bench was separated and labeled into 6 sections – one for each disinfectant, and the last section was used for a control. The area was contaminated with germs from the experimenter’s hands, lab coats, and spit. After the area was given a chance to air dry, one milliliter of each disinfectant was applied to its designated area. The disinfectant was able to interact with the surface for about five minutes before they were wiped up by using circular motions. After all surfaces were dry, sterile cotton swabs were used to transfer remaining bacteria from the bench surface to the nutrient agar dishes. All plates were incubated at 37 degrees for 48 hours. Results After 48 hours, all plates were removed from the incubator and counted for colo...