Hot Water for Handwashing - Where is the Proof?
The initial experiment involved
testing with bland non-antimicrobial
soap at 5 temperatures from 4.4°C
(40°F) to 49°C (120°F). Independent of
soil or bacterial type (resident or
transient) there was no significant
difference in efficacy attributed to
In the second experiment antimicrobial
soaps were used having different
antimicrobial active ingredients, at
each of two water temperatures, 29.5°C
(85°F) and 43°C (110°F).
In this experiment, even though
slightly higher efficacy was seen
with antimicrobial soaps at higher
temperatures, overall, there was no
statistical difference in efficacy ... at the two
Concomitant to the increase in
efficacy at higher temperatures was a
consistent trend for increases in
measures of skin damage, such as skin
moisture content, transepidermal water
loss and erythema. This was also found
not to be statistically significant.
As has been shown by many previous
researchers, overall handwashing
effectiveness is more dependent on the
vigorousness of execution than details
such as the type of soap, the length
of handwash or in this case water
For the complete text of the paper go here (it references more than 50 publications).