• Ethanol 96%: 8333 ml
• Hydrogen peroxide 3%: 417 ml
• Glycerol 98%: 145 ml
Formula 2:
• Isopropyl alcohol 99.8%:
7515 ml
• Hydrogen peroxide 3%: 417 ml
• Glycerol 98%: 145 ml
Edit: Top off with distilled water until you get 10L of product.
My justification is argument from authority. I have no explicit model. Although both formulas use high concentrations of alcohol which are known to be effective disinfectants.
If 99%+ isopropyl alcohol becomes unavailable, it looks like the other common concentrations are 70% and 91%. Using 70% isopropyl alcohol and not diluting gives you 65% alcohol, which is below the 75% in the recipe—anyone know if 65% is likely to be effective?
In that case you can use the straight 70 % isopropyl alcohol as a sanitizer and be fine. According to the WHO guidelines, only the isopropyl alcohol is the effective substance in the recipe. The hydrogen peroxide is ‘used to inactivate bacterial spores in the solution’. If you buy medical-grade 70 % isopropyl alcohol, there shouldn’t be any bacterial spores in it.
The glycerol serves as a humectant. If you don’t add it, you might have to use more sanitizer in order to keep your skin wet for the whole thirty seconds. And you’ll have to keep your skin happy in some way separate from the sanitizing.
Normally something with AfA as justification would be moved to comments, but it’s useful and extremely specific in ways that can still be the foundations for a good argument, so we’re leaving it in answers.
Hand sanitizer is a poor substitute for actually washing your hands with soap and water.
Coronaviruses are “enveloped” viruses, which means they have a fat-based shell that protects the genetic material and (presumably) aids it in infecting a cell.
Destroying this shell “kills” the virus.
While an alcohol sanitizer can of course dissolve the fats in the shell, it is difficult to get enough alcohol all over the skin to do this.
Soap is more effective because it actively attacks fats, and of course washing your hands provides far more volume and time in which to destroy the virus shells.
Studies confirm the efficacy of hand sanitizer against enveloped viruses [1][2]. Although there is some evidence that handwashing is preferable against viruses [3].
Hand sanitizer is becoming hard to find. Here are some WHO guidelines on making your own :
https://www.who.int/gpsc/5may/Guide_to_Local_Production.pdf
Formula 1:
• Ethanol 96%: 8333 ml • Hydrogen peroxide 3%: 417 ml • Glycerol 98%: 145 ml
Formula 2:
• Isopropyl alcohol 99.8%: 7515 ml • Hydrogen peroxide 3%: 417 ml • Glycerol 98%: 145 ml
Edit: Top off with distilled water until you get 10L of product.
My justification is argument from authority. I have no explicit model. Although both formulas use high concentrations of alcohol which are known to be effective disinfectants.
(FactorialCode has fixed it.)
The formulas above are incomplete. You have to fill them up to ten litres with water. Thus it is written in the PDF.
(As far as I know, too high an alcohol concentration makes the sanitizer less effective.)
Good catch.
If 99%+ isopropyl alcohol becomes unavailable, it looks like the other common concentrations are 70% and 91%. Using 70% isopropyl alcohol and not diluting gives you 65% alcohol, which is below the 75% in the recipe—anyone know if 65% is likely to be effective?
In that case you can use the straight 70 % isopropyl alcohol as a sanitizer and be fine. According to the WHO guidelines, only the isopropyl alcohol is the effective substance in the recipe. The hydrogen peroxide is ‘used to inactivate bacterial spores in the solution’. If you buy medical-grade 70 % isopropyl alcohol, there shouldn’t be any bacterial spores in it.
The glycerol serves as a humectant. If you don’t add it, you might have to use more sanitizer in order to keep your skin wet for the whole thirty seconds. And you’ll have to keep your skin happy in some way separate from the sanitizing.
Normally something with AfA as justification would be moved to comments, but it’s useful and extremely specific in ways that can still be the foundations for a good argument, so we’re leaving it in answers.
I feel like citing WHO is just about as valid as it gets in this context. WHO is just as much “from authority” as citing a few scientific papers.
Hand sanitizer is a poor substitute for actually washing your hands with soap and water.
Coronaviruses are “enveloped” viruses, which means they have a fat-based shell that protects the genetic material and (presumably) aids it in infecting a cell.
Destroying this shell “kills” the virus.
While an alcohol sanitizer can of course dissolve the fats in the shell, it is difficult to get enough alcohol all over the skin to do this.
Soap is more effective because it actively attacks fats, and of course washing your hands provides far more volume and time in which to destroy the virus shells.
What is your source for this? The CDC recommends hand sanitizer in cases where washing is not easily possible. https://www.cdc.gov/coronavirus/2019-ncov/about/prevention-treatment.html
Studies confirm the efficacy of hand sanitizer against enveloped viruses [1][2]. Although there is some evidence that handwashing is preferable against viruses [3].
[1] https://academic.oup.com/jid/article/215/6/902/2965582
[2] https://apps.who.int/iris/bitstream/handle/10665/44102/9789241597906_eng.pdf;jsessionid=D50A762FABCFB1569406859669F8FAD4?sequence=1
[3] https://msphere.asm.org/content/4/5/e00474-19