Sanitiser
Alan and others
I'm about to start making sanitiser from isopropyl alcohol (99.9%) and (does not say but I guess close 100%) glycerol. I also have some Aloe Vera 99.7% gel - as maybe kinder to hands alternative to glycerol.
My bottom line is that the alcohol content is best at 70% - 80%. Some sanitisers use only 70% (as is NHS recommended). Going up is worse for hands, but also worse for viruses. I think the US FDA suggestion is that anything over 60% will kill viruses but I doubt soon enough to be great.
I'm not using H2O2 since don't have any and its only utility seems to be destroying spores of chlostridium difficile. Not a problem for us.
So: what proportion water vs glycerol, or water vs aloe vera gel is sensible for a sanitiser the right consistency?
The WHO recipe is
• Isopropyl alcohol 99.8%:7515 ml
• Hydrogen peroxide 3%: 417 ml
• Glycerol 98%: 145 ml
Water: 1923 ml
I'd translate that is:
IPA: 75%
H2O: 23.5%
Glycerol: 1.5%
(EDITED)
Any comments? Mainly the H2O / glycerol ratio will determine final viscosity and is probably quite critical, so I'd be interested in advice from people who have done this.