"Handwashing is considered an important public health measure to prevent communicable diseases such as gastrointestinal and respiratory infections. The sinks in public toilets are often only equipped with cold water, and it can often be observed that users only briefly rinse their hands after using the toilet, instead of properly washing them with soap," recently wrote Romana Kordasiewicz-Stingler from the Institute for Hygiene and Applied Immunology at MedUni Vienna and her co-authors in a publication of the German Society for General and Hospital Hygiene.

Cold or Warm Water for Handwashing?

Since there are no recommendations regarding the optimal water temperature for the effectiveness of handwashing, the effectiveness of simple hand rinsing with cold (four degrees Celsius) and warm (40 degrees Celsius) water for ten and 20 seconds was compared, the experts explained the initial situation. The organization of the experiment: Subjects formed five "treatment groups" with three participants each. They contaminated the fingertips of their hands by dipping them into water contaminated with E. coli bacteria. Then the hands were allowed to dry, followed by handwashing with cold or warm water, with different durations, etc. Before and after, the germ contamination was measured. E. coli germs are classic intestinal bacteria and triggers of diarrheal diseases, etc.

The main results of the study: Ten seconds of handwashing with cold water led to a decrease in germ concentration by 1.93 log units (two log units: minus 99 percent). There was statistically no difference from using water at 40 degrees Celsius (minus 2.01 log units). It was quite similar for a 20-second duration of the washing process (cold water minus 2.23 log units; warm water minus 2.39 log units). However, the stronger effect of the longer handwashing was already statistically significant compared to just ten seconds.

How Long Should You Wash Your Hands?

All experimental setups were statistically inferior to a one-minute handwashing with soap. This reduced the number of germs on the fingers by 2.68 log units.

Rinsing hands for ten or 20 seconds with cold (...) or warm water "was significantly worse than the one-minute reference procedure of handwashing with Sapo kalinus (potassium soap; note), but there were no significant differences between the use of cold or warm water in pairwise comparison for both times. However, the duration seems to affect germ reduction, as the differences between the hand rinsing times for both temperatures were significant," the scientists noted in the summary of their study.

The Conclusion

Whether you wash your hands with cold or warm water after using the toilet makes no difference. The duration of the washing process and the use of soap are more likely to make a difference.

(APA/Red.)

This article has been automatically translated, read the original article here.