Many of us from early childhood have heard that hot water with soap cleans best. But is there any scientific evidence to support this statement? A new study answers this question, writes likar.info.
Management under the control over products and medicines USA (FDA) reports that warm water is more effective for removing germs from hands, so they require that the temperature of the water in restaurants, cafeterias and other catering establishments was 40 ° C with an error of two degrees.
The rationale of this requirement is that the hot water promotes the formation of soap foam, which helps get rid of germs. However, if it is proven by scientific?
Scientists drew attention to the fact that there is no scientific evidence that would confirm that to kill germs during hand washing requires hot water. New research shows that cold water copes with this task not worse.
The study was conducted by researchers from Rutgers University – new Brunswick in new Jersey, and the results were published in the Journal of Food Protection.
In the new study studied the effect of various factors such as the amount of soap, water temperature and time of foaming, the effectiveness of hand washing.
In the beginning of the study, participants used one milliliter non-antibacterial soap for foaming for five seconds at a water temperature of 38 ° C.
The study was conducted with bacteria of ATSS 11229, non-pathogenic strain of Escherichia coli.
Scientists studied the effects of hot and cold water for hand washing with the participation of 20 volunteers, including 10 men and 10 women. Each test was repeated 20 times within 6 months. During this time, participants washed their hands in the water, which was 16 ° C, 26 ° C or 38 ° C. the Amount of soap used also differed: participants wash their hands 0.5 milliliters, one milliliter, or two milliliters of soap.
Overall, the use of antimicrobial soap was not more effective than using ordinary soap. However, the expansion has greatly improved the efficiency in one experiment.
It is important to note that water temperature also has no significant effect on the removal of bacteria. Regardless, the water was 38 ° C or 16 ° C, researchers found no difference in the reduction of bacteria.
In addition, the study showed that 10 seconds is enough to effectively remove germs.
Donald Shaffner, the study’s author, Professor and specialist in the dissemination of knowledge about food products, believes that people should feel comfortable while washing hands, but the temperature of the water being used is irrelevant for getting rid of germs.