Recently, WHO recommended 75% IPA for hand sanitizers. Earlier recommended IPA percentage was 65-70%. When the IPA percentage goes up, water content goes down. It means the evaporation rate of IPA becomes high. Therefore, the contact time becomes low. I conducted a lab trial with two concentrations of IPA. 65% and 70%. 65% IPA containing hand sanitizer gave a good result than 70% IPA hand sanitizer. In this case, will 75% provide a good result?
Ethyl alcohol or Iso Propyl Alcohol basically denatures the cell wall proteings and pertubate the wall, resulting in microbial cell leakage .
> Anticeptic Activity ∝ Product concentration
> Anticeptic activity ∝ Contact time
Therefore, even if the cocentration is lower, if the contact time is high, a lower concentration can demonstrate good anticeptic activity.
For your question,
Research provide proof that SARSCov 19 can be killed from ETOH and IPA concentrations ranging from 62 - 90 %. And the virus can be killed at a lower contact time as 15 seconds. See the reference Article Ethanol and Isopropanol Inactivation of Human Coronavirus on...
It is my personal belief that WHO apporved 75% IPA concentration depending on high concentration and lower contat time; for increased efficacy and convenience of daily usage respectively.
I have a question of my own.
Since you mentioned that you conducted a lab trial,
> I would like to know the procedure.
When WHO mentioned 75% IPA for hand sanitizers, at present times it was targeted solely on covid outbreak. Since thats the case,
> I would like to know whether you conducted this experiment using two IPA concentrations on a Corona virus infected human cell line?